Merge branch 'ds/partial-clone-fixes' into maint
[git] / dir.c
1 /*
2  * This handles recursive filename detection with exclude
3  * files, index knowledge etc..
4  *
5  * Copyright (C) Linus Torvalds, 2005-2006
6  *               Junio Hamano, 2005-2006
7  */
8 #include "cache.h"
9 #include "config.h"
10 #include "dir.h"
11 #include "object-store.h"
12 #include "attr.h"
13 #include "refs.h"
14 #include "wildmatch.h"
15 #include "pathspec.h"
16 #include "utf8.h"
17 #include "varint.h"
18 #include "ewah/ewok.h"
19 #include "fsmonitor.h"
20 #include "submodule-config.h"
21
22 /*
23  * Tells read_directory_recursive how a file or directory should be treated.
24  * Values are ordered by significance, e.g. if a directory contains both
25  * excluded and untracked files, it is listed as untracked because
26  * path_untracked > path_excluded.
27  */
28 enum path_treatment {
29         path_none = 0,
30         path_recurse,
31         path_excluded,
32         path_untracked
33 };
34
35 /*
36  * Support data structure for our opendir/readdir/closedir wrappers
37  */
38 struct cached_dir {
39         DIR *fdir;
40         struct untracked_cache_dir *untracked;
41         int nr_files;
42         int nr_dirs;
43
44         const char *d_name;
45         int d_type;
46         const char *file;
47         struct untracked_cache_dir *ucd;
48 };
49
50 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
51         struct index_state *istate, const char *path, int len,
52         struct untracked_cache_dir *untracked,
53         int check_only, int stop_at_first_file, const struct pathspec *pathspec);
54 static int resolve_dtype(int dtype, struct index_state *istate,
55                          const char *path, int len);
56
57 int count_slashes(const char *s)
58 {
59         int cnt = 0;
60         while (*s)
61                 if (*s++ == '/')
62                         cnt++;
63         return cnt;
64 }
65
66 int fspathcmp(const char *a, const char *b)
67 {
68         return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
69 }
70
71 int fspathncmp(const char *a, const char *b, size_t count)
72 {
73         return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
74 }
75
76 int git_fnmatch(const struct pathspec_item *item,
77                 const char *pattern, const char *string,
78                 int prefix)
79 {
80         if (prefix > 0) {
81                 if (ps_strncmp(item, pattern, string, prefix))
82                         return WM_NOMATCH;
83                 pattern += prefix;
84                 string += prefix;
85         }
86         if (item->flags & PATHSPEC_ONESTAR) {
87                 int pattern_len = strlen(++pattern);
88                 int string_len = strlen(string);
89                 return string_len < pattern_len ||
90                         ps_strcmp(item, pattern,
91                                   string + string_len - pattern_len);
92         }
93         if (item->magic & PATHSPEC_GLOB)
94                 return wildmatch(pattern, string,
95                                  WM_PATHNAME |
96                                  (item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0));
97         else
98                 /* wildmatch has not learned no FNM_PATHNAME mode yet */
99                 return wildmatch(pattern, string,
100                                  item->magic & PATHSPEC_ICASE ? WM_CASEFOLD : 0);
101 }
102
103 static int fnmatch_icase_mem(const char *pattern, int patternlen,
104                              const char *string, int stringlen,
105                              int flags)
106 {
107         int match_status;
108         struct strbuf pat_buf = STRBUF_INIT;
109         struct strbuf str_buf = STRBUF_INIT;
110         const char *use_pat = pattern;
111         const char *use_str = string;
112
113         if (pattern[patternlen]) {
114                 strbuf_add(&pat_buf, pattern, patternlen);
115                 use_pat = pat_buf.buf;
116         }
117         if (string[stringlen]) {
118                 strbuf_add(&str_buf, string, stringlen);
119                 use_str = str_buf.buf;
120         }
121
122         if (ignore_case)
123                 flags |= WM_CASEFOLD;
124         match_status = wildmatch(use_pat, use_str, flags);
125
126         strbuf_release(&pat_buf);
127         strbuf_release(&str_buf);
128
129         return match_status;
130 }
131
132 static size_t common_prefix_len(const struct pathspec *pathspec)
133 {
134         int n;
135         size_t max = 0;
136
137         /*
138          * ":(icase)path" is treated as a pathspec full of
139          * wildcard. In other words, only prefix is considered common
140          * prefix. If the pathspec is abc/foo abc/bar, running in
141          * subdir xyz, the common prefix is still xyz, not xyz/abc as
142          * in non-:(icase).
143          */
144         GUARD_PATHSPEC(pathspec,
145                        PATHSPEC_FROMTOP |
146                        PATHSPEC_MAXDEPTH |
147                        PATHSPEC_LITERAL |
148                        PATHSPEC_GLOB |
149                        PATHSPEC_ICASE |
150                        PATHSPEC_EXCLUDE |
151                        PATHSPEC_ATTR);
152
153         for (n = 0; n < pathspec->nr; n++) {
154                 size_t i = 0, len = 0, item_len;
155                 if (pathspec->items[n].magic & PATHSPEC_EXCLUDE)
156                         continue;
157                 if (pathspec->items[n].magic & PATHSPEC_ICASE)
158                         item_len = pathspec->items[n].prefix;
159                 else
160                         item_len = pathspec->items[n].nowildcard_len;
161                 while (i < item_len && (n == 0 || i < max)) {
162                         char c = pathspec->items[n].match[i];
163                         if (c != pathspec->items[0].match[i])
164                                 break;
165                         if (c == '/')
166                                 len = i + 1;
167                         i++;
168                 }
169                 if (n == 0 || len < max) {
170                         max = len;
171                         if (!max)
172                                 break;
173                 }
174         }
175         return max;
176 }
177
178 /*
179  * Returns a copy of the longest leading path common among all
180  * pathspecs.
181  */
182 char *common_prefix(const struct pathspec *pathspec)
183 {
184         unsigned long len = common_prefix_len(pathspec);
185
186         return len ? xmemdupz(pathspec->items[0].match, len) : NULL;
187 }
188
189 int fill_directory(struct dir_struct *dir,
190                    struct index_state *istate,
191                    const struct pathspec *pathspec)
192 {
193         const char *prefix;
194         size_t prefix_len;
195
196         /*
197          * Calculate common prefix for the pathspec, and
198          * use that to optimize the directory walk
199          */
200         prefix_len = common_prefix_len(pathspec);
201         prefix = prefix_len ? pathspec->items[0].match : "";
202
203         /* Read the directory and prune it */
204         read_directory(dir, istate, prefix, prefix_len, pathspec);
205
206         return prefix_len;
207 }
208
209 int within_depth(const char *name, int namelen,
210                         int depth, int max_depth)
211 {
212         const char *cp = name, *cpe = name + namelen;
213
214         while (cp < cpe) {
215                 if (*cp++ != '/')
216                         continue;
217                 depth++;
218                 if (depth > max_depth)
219                         return 0;
220         }
221         return 1;
222 }
223
224 /*
225  * Read the contents of the blob with the given OID into a buffer.
226  * Append a trailing LF to the end if the last line doesn't have one.
227  *
228  * Returns:
229  *    -1 when the OID is invalid or unknown or does not refer to a blob.
230  *     0 when the blob is empty.
231  *     1 along with { data, size } of the (possibly augmented) buffer
232  *       when successful.
233  *
234  * Optionally updates the given oid_stat with the given OID (when valid).
235  */
236 static int do_read_blob(const struct object_id *oid, struct oid_stat *oid_stat,
237                         size_t *size_out, char **data_out)
238 {
239         enum object_type type;
240         unsigned long sz;
241         char *data;
242
243         *size_out = 0;
244         *data_out = NULL;
245
246         data = read_object_file(oid, &type, &sz);
247         if (!data || type != OBJ_BLOB) {
248                 free(data);
249                 return -1;
250         }
251
252         if (oid_stat) {
253                 memset(&oid_stat->stat, 0, sizeof(oid_stat->stat));
254                 oidcpy(&oid_stat->oid, oid);
255         }
256
257         if (sz == 0) {
258                 free(data);
259                 return 0;
260         }
261
262         if (data[sz - 1] != '\n') {
263                 data = xrealloc(data, st_add(sz, 1));
264                 data[sz++] = '\n';
265         }
266
267         *size_out = xsize_t(sz);
268         *data_out = data;
269
270         return 1;
271 }
272
273 #define DO_MATCH_EXCLUDE   (1<<0)
274 #define DO_MATCH_DIRECTORY (1<<1)
275 #define DO_MATCH_LEADING_PATHSPEC (1<<2)
276
277 /*
278  * Does the given pathspec match the given name?  A match is found if
279  *
280  * (1) the pathspec string is leading directory of 'name' ("RECURSIVELY"), or
281  * (2) the pathspec string has a leading part matching 'name' ("LEADING"), or
282  * (3) the pathspec string is a wildcard and matches 'name' ("WILDCARD"), or
283  * (4) the pathspec string is exactly the same as 'name' ("EXACT").
284  *
285  * Return value tells which case it was (1-4), or 0 when there is no match.
286  *
287  * It may be instructive to look at a small table of concrete examples
288  * to understand the differences between 1, 2, and 4:
289  *
290  *                              Pathspecs
291  *                |    a/b    |   a/b/    |   a/b/c
292  *          ------+-----------+-----------+------------
293  *          a/b   |  EXACT    |  EXACT[1] | LEADING[2]
294  *  Names   a/b/  | RECURSIVE |   EXACT   | LEADING[2]
295  *          a/b/c | RECURSIVE | RECURSIVE |   EXACT
296  *
297  * [1] Only if DO_MATCH_DIRECTORY is passed; otherwise, this is NOT a match.
298  * [2] Only if DO_MATCH_LEADING_PATHSPEC is passed; otherwise, not a match.
299  */
300 static int match_pathspec_item(const struct index_state *istate,
301                                const struct pathspec_item *item, int prefix,
302                                const char *name, int namelen, unsigned flags)
303 {
304         /* name/namelen has prefix cut off by caller */
305         const char *match = item->match + prefix;
306         int matchlen = item->len - prefix;
307
308         /*
309          * The normal call pattern is:
310          * 1. prefix = common_prefix_len(ps);
311          * 2. prune something, or fill_directory
312          * 3. match_pathspec()
313          *
314          * 'prefix' at #1 may be shorter than the command's prefix and
315          * it's ok for #2 to match extra files. Those extras will be
316          * trimmed at #3.
317          *
318          * Suppose the pathspec is 'foo' and '../bar' running from
319          * subdir 'xyz'. The common prefix at #1 will be empty, thanks
320          * to "../". We may have xyz/foo _and_ XYZ/foo after #2. The
321          * user does not want XYZ/foo, only the "foo" part should be
322          * case-insensitive. We need to filter out XYZ/foo here. In
323          * other words, we do not trust the caller on comparing the
324          * prefix part when :(icase) is involved. We do exact
325          * comparison ourselves.
326          *
327          * Normally the caller (common_prefix_len() in fact) does
328          * _exact_ matching on name[-prefix+1..-1] and we do not need
329          * to check that part. Be defensive and check it anyway, in
330          * case common_prefix_len is changed, or a new caller is
331          * introduced that does not use common_prefix_len.
332          *
333          * If the penalty turns out too high when prefix is really
334          * long, maybe change it to
335          * strncmp(match, name, item->prefix - prefix)
336          */
337         if (item->prefix && (item->magic & PATHSPEC_ICASE) &&
338             strncmp(item->match, name - prefix, item->prefix))
339                 return 0;
340
341         if (item->attr_match_nr &&
342             !match_pathspec_attrs(istate, name, namelen, item))
343                 return 0;
344
345         /* If the match was just the prefix, we matched */
346         if (!*match)
347                 return MATCHED_RECURSIVELY;
348
349         if (matchlen <= namelen && !ps_strncmp(item, match, name, matchlen)) {
350                 if (matchlen == namelen)
351                         return MATCHED_EXACTLY;
352
353                 if (match[matchlen-1] == '/' || name[matchlen] == '/')
354                         return MATCHED_RECURSIVELY;
355         } else if ((flags & DO_MATCH_DIRECTORY) &&
356                    match[matchlen - 1] == '/' &&
357                    namelen == matchlen - 1 &&
358                    !ps_strncmp(item, match, name, namelen))
359                 return MATCHED_EXACTLY;
360
361         if (item->nowildcard_len < item->len &&
362             !git_fnmatch(item, match, name,
363                          item->nowildcard_len - prefix))
364                 return MATCHED_FNMATCH;
365
366         /* Perform checks to see if "name" is a leading string of the pathspec */
367         if (flags & DO_MATCH_LEADING_PATHSPEC) {
368                 /* name is a literal prefix of the pathspec */
369                 int offset = name[namelen-1] == '/' ? 1 : 0;
370                 if ((namelen < matchlen) &&
371                     (match[namelen-offset] == '/') &&
372                     !ps_strncmp(item, match, name, namelen))
373                         return MATCHED_RECURSIVELY_LEADING_PATHSPEC;
374
375                 /* name doesn't match up to the first wild character */
376                 if (item->nowildcard_len < item->len &&
377                     ps_strncmp(item, match, name,
378                                item->nowildcard_len - prefix))
379                         return 0;
380
381                 /*
382                  * name has no wildcard, and it didn't match as a leading
383                  * pathspec so return.
384                  */
385                 if (item->nowildcard_len == item->len)
386                         return 0;
387
388                 /*
389                  * Here is where we would perform a wildmatch to check if
390                  * "name" can be matched as a directory (or a prefix) against
391                  * the pathspec.  Since wildmatch doesn't have this capability
392                  * at the present we have to punt and say that it is a match,
393                  * potentially returning a false positive
394                  * The submodules themselves will be able to perform more
395                  * accurate matching to determine if the pathspec matches.
396                  */
397                 return MATCHED_RECURSIVELY_LEADING_PATHSPEC;
398         }
399
400         return 0;
401 }
402
403 /*
404  * Given a name and a list of pathspecs, returns the nature of the
405  * closest (i.e. most specific) match of the name to any of the
406  * pathspecs.
407  *
408  * The caller typically calls this multiple times with the same
409  * pathspec and seen[] array but with different name/namelen
410  * (e.g. entries from the index) and is interested in seeing if and
411  * how each pathspec matches all the names it calls this function
412  * with.  A mark is left in the seen[] array for each pathspec element
413  * indicating the closest type of match that element achieved, so if
414  * seen[n] remains zero after multiple invocations, that means the nth
415  * pathspec did not match any names, which could indicate that the
416  * user mistyped the nth pathspec.
417  */
418 static int do_match_pathspec(const struct index_state *istate,
419                              const struct pathspec *ps,
420                              const char *name, int namelen,
421                              int prefix, char *seen,
422                              unsigned flags)
423 {
424         int i, retval = 0, exclude = flags & DO_MATCH_EXCLUDE;
425
426         GUARD_PATHSPEC(ps,
427                        PATHSPEC_FROMTOP |
428                        PATHSPEC_MAXDEPTH |
429                        PATHSPEC_LITERAL |
430                        PATHSPEC_GLOB |
431                        PATHSPEC_ICASE |
432                        PATHSPEC_EXCLUDE |
433                        PATHSPEC_ATTR);
434
435         if (!ps->nr) {
436                 if (!ps->recursive ||
437                     !(ps->magic & PATHSPEC_MAXDEPTH) ||
438                     ps->max_depth == -1)
439                         return MATCHED_RECURSIVELY;
440
441                 if (within_depth(name, namelen, 0, ps->max_depth))
442                         return MATCHED_EXACTLY;
443                 else
444                         return 0;
445         }
446
447         name += prefix;
448         namelen -= prefix;
449
450         for (i = ps->nr - 1; i >= 0; i--) {
451                 int how;
452
453                 if ((!exclude &&   ps->items[i].magic & PATHSPEC_EXCLUDE) ||
454                     ( exclude && !(ps->items[i].magic & PATHSPEC_EXCLUDE)))
455                         continue;
456
457                 if (seen && seen[i] == MATCHED_EXACTLY)
458                         continue;
459                 /*
460                  * Make exclude patterns optional and never report
461                  * "pathspec ':(exclude)foo' matches no files"
462                  */
463                 if (seen && ps->items[i].magic & PATHSPEC_EXCLUDE)
464                         seen[i] = MATCHED_FNMATCH;
465                 how = match_pathspec_item(istate, ps->items+i, prefix, name,
466                                           namelen, flags);
467                 if (ps->recursive &&
468                     (ps->magic & PATHSPEC_MAXDEPTH) &&
469                     ps->max_depth != -1 &&
470                     how && how != MATCHED_FNMATCH) {
471                         int len = ps->items[i].len;
472                         if (name[len] == '/')
473                                 len++;
474                         if (within_depth(name+len, namelen-len, 0, ps->max_depth))
475                                 how = MATCHED_EXACTLY;
476                         else
477                                 how = 0;
478                 }
479                 if (how) {
480                         if (retval < how)
481                                 retval = how;
482                         if (seen && seen[i] < how)
483                                 seen[i] = how;
484                 }
485         }
486         return retval;
487 }
488
489 int match_pathspec(const struct index_state *istate,
490                    const struct pathspec *ps,
491                    const char *name, int namelen,
492                    int prefix, char *seen, int is_dir)
493 {
494         int positive, negative;
495         unsigned flags = is_dir ? DO_MATCH_DIRECTORY : 0;
496         positive = do_match_pathspec(istate, ps, name, namelen,
497                                      prefix, seen, flags);
498         if (!(ps->magic & PATHSPEC_EXCLUDE) || !positive)
499                 return positive;
500         negative = do_match_pathspec(istate, ps, name, namelen,
501                                      prefix, seen,
502                                      flags | DO_MATCH_EXCLUDE);
503         return negative ? 0 : positive;
504 }
505
506 /**
507  * Check if a submodule is a superset of the pathspec
508  */
509 int submodule_path_match(const struct index_state *istate,
510                          const struct pathspec *ps,
511                          const char *submodule_name,
512                          char *seen)
513 {
514         int matched = do_match_pathspec(istate, ps, submodule_name,
515                                         strlen(submodule_name),
516                                         0, seen,
517                                         DO_MATCH_DIRECTORY |
518                                         DO_MATCH_LEADING_PATHSPEC);
519         return matched;
520 }
521
522 int report_path_error(const char *ps_matched,
523                       const struct pathspec *pathspec)
524 {
525         /*
526          * Make sure all pathspec matched; otherwise it is an error.
527          */
528         int num, errors = 0;
529         for (num = 0; num < pathspec->nr; num++) {
530                 int other, found_dup;
531
532                 if (ps_matched[num])
533                         continue;
534                 /*
535                  * The caller might have fed identical pathspec
536                  * twice.  Do not barf on such a mistake.
537                  * FIXME: parse_pathspec should have eliminated
538                  * duplicate pathspec.
539                  */
540                 for (found_dup = other = 0;
541                      !found_dup && other < pathspec->nr;
542                      other++) {
543                         if (other == num || !ps_matched[other])
544                                 continue;
545                         if (!strcmp(pathspec->items[other].original,
546                                     pathspec->items[num].original))
547                                 /*
548                                  * Ok, we have a match already.
549                                  */
550                                 found_dup = 1;
551                 }
552                 if (found_dup)
553                         continue;
554
555                 error(_("pathspec '%s' did not match any file(s) known to git"),
556                       pathspec->items[num].original);
557                 errors++;
558         }
559         return errors;
560 }
561
562 /*
563  * Return the length of the "simple" part of a path match limiter.
564  */
565 int simple_length(const char *match)
566 {
567         int len = -1;
568
569         for (;;) {
570                 unsigned char c = *match++;
571                 len++;
572                 if (c == '\0' || is_glob_special(c))
573                         return len;
574         }
575 }
576
577 int no_wildcard(const char *string)
578 {
579         return string[simple_length(string)] == '\0';
580 }
581
582 void parse_path_pattern(const char **pattern,
583                            int *patternlen,
584                            unsigned *flags,
585                            int *nowildcardlen)
586 {
587         const char *p = *pattern;
588         size_t i, len;
589
590         *flags = 0;
591         if (*p == '!') {
592                 *flags |= PATTERN_FLAG_NEGATIVE;
593                 p++;
594         }
595         len = strlen(p);
596         if (len && p[len - 1] == '/') {
597                 len--;
598                 *flags |= PATTERN_FLAG_MUSTBEDIR;
599         }
600         for (i = 0; i < len; i++) {
601                 if (p[i] == '/')
602                         break;
603         }
604         if (i == len)
605                 *flags |= PATTERN_FLAG_NODIR;
606         *nowildcardlen = simple_length(p);
607         /*
608          * we should have excluded the trailing slash from 'p' too,
609          * but that's one more allocation. Instead just make sure
610          * nowildcardlen does not exceed real patternlen
611          */
612         if (*nowildcardlen > len)
613                 *nowildcardlen = len;
614         if (*p == '*' && no_wildcard(p + 1))
615                 *flags |= PATTERN_FLAG_ENDSWITH;
616         *pattern = p;
617         *patternlen = len;
618 }
619
620 int pl_hashmap_cmp(const void *unused_cmp_data,
621                    const struct hashmap_entry *a,
622                    const struct hashmap_entry *b,
623                    const void *key)
624 {
625         const struct pattern_entry *ee1 =
626                         container_of(a, struct pattern_entry, ent);
627         const struct pattern_entry *ee2 =
628                         container_of(b, struct pattern_entry, ent);
629
630         size_t min_len = ee1->patternlen <= ee2->patternlen
631                          ? ee1->patternlen
632                          : ee2->patternlen;
633
634         if (ignore_case)
635                 return strncasecmp(ee1->pattern, ee2->pattern, min_len);
636         return strncmp(ee1->pattern, ee2->pattern, min_len);
637 }
638
639 static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern *given)
640 {
641         struct pattern_entry *translated;
642         char *truncated;
643         char *data = NULL;
644
645         if (!pl->use_cone_patterns)
646                 return;
647
648         if (given->flags & PATTERN_FLAG_NEGATIVE &&
649             given->flags & PATTERN_FLAG_MUSTBEDIR &&
650             !strcmp(given->pattern, "/*")) {
651                 pl->full_cone = 0;
652                 return;
653         }
654
655         if (!given->flags && !strcmp(given->pattern, "/*")) {
656                 pl->full_cone = 1;
657                 return;
658         }
659
660         if (given->patternlen > 2 &&
661             !strcmp(given->pattern + given->patternlen - 2, "/*")) {
662                 if (!(given->flags & PATTERN_FLAG_NEGATIVE)) {
663                         /* Not a cone pattern. */
664                         pl->use_cone_patterns = 0;
665                         warning(_("unrecognized pattern: '%s'"), given->pattern);
666                         goto clear_hashmaps;
667                 }
668
669                 truncated = xstrdup(given->pattern);
670                 truncated[given->patternlen - 2] = 0;
671
672                 translated = xmalloc(sizeof(struct pattern_entry));
673                 translated->pattern = truncated;
674                 translated->patternlen = given->patternlen - 2;
675                 hashmap_entry_init(&translated->ent,
676                                    ignore_case ?
677                                    strihash(translated->pattern) :
678                                    strhash(translated->pattern));
679
680                 if (!hashmap_get_entry(&pl->recursive_hashmap,
681                                        translated, ent, NULL)) {
682                         /* We did not see the "parent" included */
683                         warning(_("unrecognized negative pattern: '%s'"),
684                                 given->pattern);
685                         free(truncated);
686                         free(translated);
687                         goto clear_hashmaps;
688                 }
689
690                 hashmap_add(&pl->parent_hashmap, &translated->ent);
691                 hashmap_remove(&pl->recursive_hashmap, &translated->ent, &data);
692                 free(data);
693                 return;
694         }
695
696         if (given->flags & PATTERN_FLAG_NEGATIVE) {
697                 warning(_("unrecognized negative pattern: '%s'"),
698                         given->pattern);
699                 goto clear_hashmaps;
700         }
701
702         translated = xmalloc(sizeof(struct pattern_entry));
703
704         translated->pattern = xstrdup(given->pattern);
705         translated->patternlen = given->patternlen;
706         hashmap_entry_init(&translated->ent,
707                            ignore_case ?
708                            strihash(translated->pattern) :
709                            strhash(translated->pattern));
710
711         hashmap_add(&pl->recursive_hashmap, &translated->ent);
712
713         if (hashmap_get_entry(&pl->parent_hashmap, translated, ent, NULL)) {
714                 /* we already included this at the parent level */
715                 warning(_("your sparse-checkout file may have issues: pattern '%s' is repeated"),
716                         given->pattern);
717                 hashmap_remove(&pl->parent_hashmap, &translated->ent, &data);
718                 free(data);
719                 free(translated);
720         }
721
722         return;
723
724 clear_hashmaps:
725         warning(_("disabling cone pattern matching"));
726         hashmap_free_entries(&pl->parent_hashmap, struct pattern_entry, ent);
727         hashmap_free_entries(&pl->recursive_hashmap, struct pattern_entry, ent);
728         pl->use_cone_patterns = 0;
729 }
730
731 static int hashmap_contains_path(struct hashmap *map,
732                                  struct strbuf *pattern)
733 {
734         struct pattern_entry p;
735
736         /* Check straight mapping */
737         p.pattern = pattern->buf;
738         p.patternlen = pattern->len;
739         hashmap_entry_init(&p.ent,
740                            ignore_case ?
741                            strihash(p.pattern) :
742                            strhash(p.pattern));
743         return !!hashmap_get_entry(map, &p, ent, NULL);
744 }
745
746 int hashmap_contains_parent(struct hashmap *map,
747                             const char *path,
748                             struct strbuf *buffer)
749 {
750         char *slash_pos;
751
752         strbuf_setlen(buffer, 0);
753
754         if (path[0] != '/')
755                 strbuf_addch(buffer, '/');
756
757         strbuf_addstr(buffer, path);
758
759         slash_pos = strrchr(buffer->buf, '/');
760
761         while (slash_pos > buffer->buf) {
762                 strbuf_setlen(buffer, slash_pos - buffer->buf);
763
764                 if (hashmap_contains_path(map, buffer))
765                         return 1;
766
767                 slash_pos = strrchr(buffer->buf, '/');
768         }
769
770         return 0;
771 }
772
773 void add_pattern(const char *string, const char *base,
774                  int baselen, struct pattern_list *pl, int srcpos)
775 {
776         struct path_pattern *pattern;
777         int patternlen;
778         unsigned flags;
779         int nowildcardlen;
780
781         parse_path_pattern(&string, &patternlen, &flags, &nowildcardlen);
782         if (flags & PATTERN_FLAG_MUSTBEDIR) {
783                 FLEXPTR_ALLOC_MEM(pattern, pattern, string, patternlen);
784         } else {
785                 pattern = xmalloc(sizeof(*pattern));
786                 pattern->pattern = string;
787         }
788         pattern->patternlen = patternlen;
789         pattern->nowildcardlen = nowildcardlen;
790         pattern->base = base;
791         pattern->baselen = baselen;
792         pattern->flags = flags;
793         pattern->srcpos = srcpos;
794         ALLOC_GROW(pl->patterns, pl->nr + 1, pl->alloc);
795         pl->patterns[pl->nr++] = pattern;
796         pattern->pl = pl;
797
798         add_pattern_to_hashsets(pl, pattern);
799 }
800
801 static int read_skip_worktree_file_from_index(const struct index_state *istate,
802                                               const char *path,
803                                               size_t *size_out, char **data_out,
804                                               struct oid_stat *oid_stat)
805 {
806         int pos, len;
807
808         len = strlen(path);
809         pos = index_name_pos(istate, path, len);
810         if (pos < 0)
811                 return -1;
812         if (!ce_skip_worktree(istate->cache[pos]))
813                 return -1;
814
815         return do_read_blob(&istate->cache[pos]->oid, oid_stat, size_out, data_out);
816 }
817
818 /*
819  * Frees memory within pl which was allocated for exclude patterns and
820  * the file buffer.  Does not free pl itself.
821  */
822 void clear_pattern_list(struct pattern_list *pl)
823 {
824         int i;
825
826         for (i = 0; i < pl->nr; i++)
827                 free(pl->patterns[i]);
828         free(pl->patterns);
829         free(pl->filebuf);
830
831         memset(pl, 0, sizeof(*pl));
832 }
833
834 static void trim_trailing_spaces(char *buf)
835 {
836         char *p, *last_space = NULL;
837
838         for (p = buf; *p; p++)
839                 switch (*p) {
840                 case ' ':
841                         if (!last_space)
842                                 last_space = p;
843                         break;
844                 case '\\':
845                         p++;
846                         if (!*p)
847                                 return;
848                         /* fallthrough */
849                 default:
850                         last_space = NULL;
851                 }
852
853         if (last_space)
854                 *last_space = '\0';
855 }
856
857 /*
858  * Given a subdirectory name and "dir" of the current directory,
859  * search the subdir in "dir" and return it, or create a new one if it
860  * does not exist in "dir".
861  *
862  * If "name" has the trailing slash, it'll be excluded in the search.
863  */
864 static struct untracked_cache_dir *lookup_untracked(struct untracked_cache *uc,
865                                                     struct untracked_cache_dir *dir,
866                                                     const char *name, int len)
867 {
868         int first, last;
869         struct untracked_cache_dir *d;
870         if (!dir)
871                 return NULL;
872         if (len && name[len - 1] == '/')
873                 len--;
874         first = 0;
875         last = dir->dirs_nr;
876         while (last > first) {
877                 int cmp, next = first + ((last - first) >> 1);
878                 d = dir->dirs[next];
879                 cmp = strncmp(name, d->name, len);
880                 if (!cmp && strlen(d->name) > len)
881                         cmp = -1;
882                 if (!cmp)
883                         return d;
884                 if (cmp < 0) {
885                         last = next;
886                         continue;
887                 }
888                 first = next+1;
889         }
890
891         uc->dir_created++;
892         FLEX_ALLOC_MEM(d, name, name, len);
893
894         ALLOC_GROW(dir->dirs, dir->dirs_nr + 1, dir->dirs_alloc);
895         MOVE_ARRAY(dir->dirs + first + 1, dir->dirs + first,
896                    dir->dirs_nr - first);
897         dir->dirs_nr++;
898         dir->dirs[first] = d;
899         return d;
900 }
901
902 static void do_invalidate_gitignore(struct untracked_cache_dir *dir)
903 {
904         int i;
905         dir->valid = 0;
906         dir->untracked_nr = 0;
907         for (i = 0; i < dir->dirs_nr; i++)
908                 do_invalidate_gitignore(dir->dirs[i]);
909 }
910
911 static void invalidate_gitignore(struct untracked_cache *uc,
912                                  struct untracked_cache_dir *dir)
913 {
914         uc->gitignore_invalidated++;
915         do_invalidate_gitignore(dir);
916 }
917
918 static void invalidate_directory(struct untracked_cache *uc,
919                                  struct untracked_cache_dir *dir)
920 {
921         int i;
922
923         /*
924          * Invalidation increment here is just roughly correct. If
925          * untracked_nr or any of dirs[].recurse is non-zero, we
926          * should increment dir_invalidated too. But that's more
927          * expensive to do.
928          */
929         if (dir->valid)
930                 uc->dir_invalidated++;
931
932         dir->valid = 0;
933         dir->untracked_nr = 0;
934         for (i = 0; i < dir->dirs_nr; i++)
935                 dir->dirs[i]->recurse = 0;
936 }
937
938 static int add_patterns_from_buffer(char *buf, size_t size,
939                                     const char *base, int baselen,
940                                     struct pattern_list *pl);
941
942 /*
943  * Given a file with name "fname", read it (either from disk, or from
944  * an index if 'istate' is non-null), parse it and store the
945  * exclude rules in "pl".
946  *
947  * If "ss" is not NULL, compute SHA-1 of the exclude file and fill
948  * stat data from disk (only valid if add_patterns returns zero). If
949  * ss_valid is non-zero, "ss" must contain good value as input.
950  */
951 static int add_patterns(const char *fname, const char *base, int baselen,
952                         struct pattern_list *pl, struct index_state *istate,
953                         struct oid_stat *oid_stat)
954 {
955         struct stat st;
956         int r;
957         int fd;
958         size_t size = 0;
959         char *buf;
960
961         fd = open(fname, O_RDONLY);
962         if (fd < 0 || fstat(fd, &st) < 0) {
963                 if (fd < 0)
964                         warn_on_fopen_errors(fname);
965                 else
966                         close(fd);
967                 if (!istate)
968                         return -1;
969                 r = read_skip_worktree_file_from_index(istate, fname,
970                                                        &size, &buf,
971                                                        oid_stat);
972                 if (r != 1)
973                         return r;
974         } else {
975                 size = xsize_t(st.st_size);
976                 if (size == 0) {
977                         if (oid_stat) {
978                                 fill_stat_data(&oid_stat->stat, &st);
979                                 oidcpy(&oid_stat->oid, the_hash_algo->empty_blob);
980                                 oid_stat->valid = 1;
981                         }
982                         close(fd);
983                         return 0;
984                 }
985                 buf = xmallocz(size);
986                 if (read_in_full(fd, buf, size) != size) {
987                         free(buf);
988                         close(fd);
989                         return -1;
990                 }
991                 buf[size++] = '\n';
992                 close(fd);
993                 if (oid_stat) {
994                         int pos;
995                         if (oid_stat->valid &&
996                             !match_stat_data_racy(istate, &oid_stat->stat, &st))
997                                 ; /* no content change, ss->sha1 still good */
998                         else if (istate &&
999                                  (pos = index_name_pos(istate, fname, strlen(fname))) >= 0 &&
1000                                  !ce_stage(istate->cache[pos]) &&
1001                                  ce_uptodate(istate->cache[pos]) &&
1002                                  !would_convert_to_git(istate, fname))
1003                                 oidcpy(&oid_stat->oid,
1004                                        &istate->cache[pos]->oid);
1005                         else
1006                                 hash_object_file(buf, size, "blob",
1007                                                  &oid_stat->oid);
1008                         fill_stat_data(&oid_stat->stat, &st);
1009                         oid_stat->valid = 1;
1010                 }
1011         }
1012
1013         add_patterns_from_buffer(buf, size, base, baselen, pl);
1014         return 0;
1015 }
1016
1017 static int add_patterns_from_buffer(char *buf, size_t size,
1018                                     const char *base, int baselen,
1019                                     struct pattern_list *pl)
1020 {
1021         int i, lineno = 1;
1022         char *entry;
1023
1024         hashmap_init(&pl->recursive_hashmap, pl_hashmap_cmp, NULL, 0);
1025         hashmap_init(&pl->parent_hashmap, pl_hashmap_cmp, NULL, 0);
1026
1027         pl->filebuf = buf;
1028
1029         if (skip_utf8_bom(&buf, size))
1030                 size -= buf - pl->filebuf;
1031
1032         entry = buf;
1033
1034         for (i = 0; i < size; i++) {
1035                 if (buf[i] == '\n') {
1036                         if (entry != buf + i && entry[0] != '#') {
1037                                 buf[i - (i && buf[i-1] == '\r')] = 0;
1038                                 trim_trailing_spaces(entry);
1039                                 add_pattern(entry, base, baselen, pl, lineno);
1040                         }
1041                         lineno++;
1042                         entry = buf + i + 1;
1043                 }
1044         }
1045         return 0;
1046 }
1047
1048 int add_patterns_from_file_to_list(const char *fname, const char *base,
1049                                    int baselen, struct pattern_list *pl,
1050                                    struct index_state *istate)
1051 {
1052         return add_patterns(fname, base, baselen, pl, istate, NULL);
1053 }
1054
1055 int add_patterns_from_blob_to_list(
1056         struct object_id *oid,
1057         const char *base, int baselen,
1058         struct pattern_list *pl)
1059 {
1060         char *buf;
1061         size_t size;
1062         int r;
1063
1064         r = do_read_blob(oid, NULL, &size, &buf);
1065         if (r != 1)
1066                 return r;
1067
1068         add_patterns_from_buffer(buf, size, base, baselen, pl);
1069         return 0;
1070 }
1071
1072 struct pattern_list *add_pattern_list(struct dir_struct *dir,
1073                                       int group_type, const char *src)
1074 {
1075         struct pattern_list *pl;
1076         struct exclude_list_group *group;
1077
1078         group = &dir->exclude_list_group[group_type];
1079         ALLOC_GROW(group->pl, group->nr + 1, group->alloc);
1080         pl = &group->pl[group->nr++];
1081         memset(pl, 0, sizeof(*pl));
1082         pl->src = src;
1083         return pl;
1084 }
1085
1086 /*
1087  * Used to set up core.excludesfile and .git/info/exclude lists.
1088  */
1089 static void add_patterns_from_file_1(struct dir_struct *dir, const char *fname,
1090                                      struct oid_stat *oid_stat)
1091 {
1092         struct pattern_list *pl;
1093         /*
1094          * catch setup_standard_excludes() that's called before
1095          * dir->untracked is assigned. That function behaves
1096          * differently when dir->untracked is non-NULL.
1097          */
1098         if (!dir->untracked)
1099                 dir->unmanaged_exclude_files++;
1100         pl = add_pattern_list(dir, EXC_FILE, fname);
1101         if (add_patterns(fname, "", 0, pl, NULL, oid_stat) < 0)
1102                 die(_("cannot use %s as an exclude file"), fname);
1103 }
1104
1105 void add_patterns_from_file(struct dir_struct *dir, const char *fname)
1106 {
1107         dir->unmanaged_exclude_files++; /* see validate_untracked_cache() */
1108         add_patterns_from_file_1(dir, fname, NULL);
1109 }
1110
1111 int match_basename(const char *basename, int basenamelen,
1112                    const char *pattern, int prefix, int patternlen,
1113                    unsigned flags)
1114 {
1115         if (prefix == patternlen) {
1116                 if (patternlen == basenamelen &&
1117                     !fspathncmp(pattern, basename, basenamelen))
1118                         return 1;
1119         } else if (flags & PATTERN_FLAG_ENDSWITH) {
1120                 /* "*literal" matching against "fooliteral" */
1121                 if (patternlen - 1 <= basenamelen &&
1122                     !fspathncmp(pattern + 1,
1123                                    basename + basenamelen - (patternlen - 1),
1124                                    patternlen - 1))
1125                         return 1;
1126         } else {
1127                 if (fnmatch_icase_mem(pattern, patternlen,
1128                                       basename, basenamelen,
1129                                       0) == 0)
1130                         return 1;
1131         }
1132         return 0;
1133 }
1134
1135 int match_pathname(const char *pathname, int pathlen,
1136                    const char *base, int baselen,
1137                    const char *pattern, int prefix, int patternlen,
1138                    unsigned flags)
1139 {
1140         const char *name;
1141         int namelen;
1142
1143         /*
1144          * match with FNM_PATHNAME; the pattern has base implicitly
1145          * in front of it.
1146          */
1147         if (*pattern == '/') {
1148                 pattern++;
1149                 patternlen--;
1150                 prefix--;
1151         }
1152
1153         /*
1154          * baselen does not count the trailing slash. base[] may or
1155          * may not end with a trailing slash though.
1156          */
1157         if (pathlen < baselen + 1 ||
1158             (baselen && pathname[baselen] != '/') ||
1159             fspathncmp(pathname, base, baselen))
1160                 return 0;
1161
1162         namelen = baselen ? pathlen - baselen - 1 : pathlen;
1163         name = pathname + pathlen - namelen;
1164
1165         if (prefix) {
1166                 /*
1167                  * if the non-wildcard part is longer than the
1168                  * remaining pathname, surely it cannot match.
1169                  */
1170                 if (prefix > namelen)
1171                         return 0;
1172
1173                 if (fspathncmp(pattern, name, prefix))
1174                         return 0;
1175                 pattern += prefix;
1176                 patternlen -= prefix;
1177                 name    += prefix;
1178                 namelen -= prefix;
1179
1180                 /*
1181                  * If the whole pattern did not have a wildcard,
1182                  * then our prefix match is all we need; we
1183                  * do not need to call fnmatch at all.
1184                  */
1185                 if (!patternlen && !namelen)
1186                         return 1;
1187         }
1188
1189         return fnmatch_icase_mem(pattern, patternlen,
1190                                  name, namelen,
1191                                  WM_PATHNAME) == 0;
1192 }
1193
1194 /*
1195  * Scan the given exclude list in reverse to see whether pathname
1196  * should be ignored.  The first match (i.e. the last on the list), if
1197  * any, determines the fate.  Returns the exclude_list element which
1198  * matched, or NULL for undecided.
1199  */
1200 static struct path_pattern *last_matching_pattern_from_list(const char *pathname,
1201                                                        int pathlen,
1202                                                        const char *basename,
1203                                                        int *dtype,
1204                                                        struct pattern_list *pl,
1205                                                        struct index_state *istate)
1206 {
1207         struct path_pattern *res = NULL; /* undecided */
1208         int i;
1209
1210         if (!pl->nr)
1211                 return NULL;    /* undefined */
1212
1213         for (i = pl->nr - 1; 0 <= i; i--) {
1214                 struct path_pattern *pattern = pl->patterns[i];
1215                 const char *exclude = pattern->pattern;
1216                 int prefix = pattern->nowildcardlen;
1217
1218                 if (pattern->flags & PATTERN_FLAG_MUSTBEDIR) {
1219                         *dtype = resolve_dtype(*dtype, istate, pathname, pathlen);
1220                         if (*dtype != DT_DIR)
1221                                 continue;
1222                 }
1223
1224                 if (pattern->flags & PATTERN_FLAG_NODIR) {
1225                         if (match_basename(basename,
1226                                            pathlen - (basename - pathname),
1227                                            exclude, prefix, pattern->patternlen,
1228                                            pattern->flags)) {
1229                                 res = pattern;
1230                                 break;
1231                         }
1232                         continue;
1233                 }
1234
1235                 assert(pattern->baselen == 0 ||
1236                        pattern->base[pattern->baselen - 1] == '/');
1237                 if (match_pathname(pathname, pathlen,
1238                                    pattern->base,
1239                                    pattern->baselen ? pattern->baselen - 1 : 0,
1240                                    exclude, prefix, pattern->patternlen,
1241                                    pattern->flags)) {
1242                         res = pattern;
1243                         break;
1244                 }
1245         }
1246         return res;
1247 }
1248
1249 /*
1250  * Scan the list of patterns to determine if the ordered list
1251  * of patterns matches on 'pathname'.
1252  *
1253  * Return 1 for a match, 0 for not matched and -1 for undecided.
1254  */
1255 enum pattern_match_result path_matches_pattern_list(
1256                                 const char *pathname, int pathlen,
1257                                 const char *basename, int *dtype,
1258                                 struct pattern_list *pl,
1259                                 struct index_state *istate)
1260 {
1261         struct path_pattern *pattern;
1262         struct strbuf parent_pathname = STRBUF_INIT;
1263         int result = NOT_MATCHED;
1264         const char *slash_pos;
1265
1266         if (!pl->use_cone_patterns) {
1267                 pattern = last_matching_pattern_from_list(pathname, pathlen, basename,
1268                                                         dtype, pl, istate);
1269                 if (pattern) {
1270                         if (pattern->flags & PATTERN_FLAG_NEGATIVE)
1271                                 return NOT_MATCHED;
1272                         else
1273                                 return MATCHED;
1274                 }
1275
1276                 return UNDECIDED;
1277         }
1278
1279         if (pl->full_cone)
1280                 return MATCHED;
1281
1282         strbuf_addch(&parent_pathname, '/');
1283         strbuf_add(&parent_pathname, pathname, pathlen);
1284
1285         if (hashmap_contains_path(&pl->recursive_hashmap,
1286                                   &parent_pathname)) {
1287                 result = MATCHED_RECURSIVE;
1288                 goto done;
1289         }
1290
1291         slash_pos = strrchr(parent_pathname.buf, '/');
1292
1293         if (slash_pos == parent_pathname.buf) {
1294                 /* include every file in root */
1295                 result = MATCHED;
1296                 goto done;
1297         }
1298
1299         strbuf_setlen(&parent_pathname, slash_pos - parent_pathname.buf);
1300
1301         if (hashmap_contains_path(&pl->parent_hashmap, &parent_pathname)) {
1302                 result = MATCHED;
1303                 goto done;
1304         }
1305
1306         if (hashmap_contains_parent(&pl->recursive_hashmap,
1307                                     pathname,
1308                                     &parent_pathname))
1309                 result = MATCHED_RECURSIVE;
1310
1311 done:
1312         strbuf_release(&parent_pathname);
1313         return result;
1314 }
1315
1316 static struct path_pattern *last_matching_pattern_from_lists(
1317                 struct dir_struct *dir, struct index_state *istate,
1318                 const char *pathname, int pathlen,
1319                 const char *basename, int *dtype_p)
1320 {
1321         int i, j;
1322         struct exclude_list_group *group;
1323         struct path_pattern *pattern;
1324         for (i = EXC_CMDL; i <= EXC_FILE; i++) {
1325                 group = &dir->exclude_list_group[i];
1326                 for (j = group->nr - 1; j >= 0; j--) {
1327                         pattern = last_matching_pattern_from_list(
1328                                 pathname, pathlen, basename, dtype_p,
1329                                 &group->pl[j], istate);
1330                         if (pattern)
1331                                 return pattern;
1332                 }
1333         }
1334         return NULL;
1335 }
1336
1337 /*
1338  * Loads the per-directory exclude list for the substring of base
1339  * which has a char length of baselen.
1340  */
1341 static void prep_exclude(struct dir_struct *dir,
1342                          struct index_state *istate,
1343                          const char *base, int baselen)
1344 {
1345         struct exclude_list_group *group;
1346         struct pattern_list *pl;
1347         struct exclude_stack *stk = NULL;
1348         struct untracked_cache_dir *untracked;
1349         int current;
1350
1351         group = &dir->exclude_list_group[EXC_DIRS];
1352
1353         /*
1354          * Pop the exclude lists from the EXCL_DIRS exclude_list_group
1355          * which originate from directories not in the prefix of the
1356          * path being checked.
1357          */
1358         while ((stk = dir->exclude_stack) != NULL) {
1359                 if (stk->baselen <= baselen &&
1360                     !strncmp(dir->basebuf.buf, base, stk->baselen))
1361                         break;
1362                 pl = &group->pl[dir->exclude_stack->exclude_ix];
1363                 dir->exclude_stack = stk->prev;
1364                 dir->pattern = NULL;
1365                 free((char *)pl->src); /* see strbuf_detach() below */
1366                 clear_pattern_list(pl);
1367                 free(stk);
1368                 group->nr--;
1369         }
1370
1371         /* Skip traversing into sub directories if the parent is excluded */
1372         if (dir->pattern)
1373                 return;
1374
1375         /*
1376          * Lazy initialization. All call sites currently just
1377          * memset(dir, 0, sizeof(*dir)) before use. Changing all of
1378          * them seems lots of work for little benefit.
1379          */
1380         if (!dir->basebuf.buf)
1381                 strbuf_init(&dir->basebuf, PATH_MAX);
1382
1383         /* Read from the parent directories and push them down. */
1384         current = stk ? stk->baselen : -1;
1385         strbuf_setlen(&dir->basebuf, current < 0 ? 0 : current);
1386         if (dir->untracked)
1387                 untracked = stk ? stk->ucd : dir->untracked->root;
1388         else
1389                 untracked = NULL;
1390
1391         while (current < baselen) {
1392                 const char *cp;
1393                 struct oid_stat oid_stat;
1394
1395                 stk = xcalloc(1, sizeof(*stk));
1396                 if (current < 0) {
1397                         cp = base;
1398                         current = 0;
1399                 } else {
1400                         cp = strchr(base + current + 1, '/');
1401                         if (!cp)
1402                                 die("oops in prep_exclude");
1403                         cp++;
1404                         untracked =
1405                                 lookup_untracked(dir->untracked, untracked,
1406                                                  base + current,
1407                                                  cp - base - current);
1408                 }
1409                 stk->prev = dir->exclude_stack;
1410                 stk->baselen = cp - base;
1411                 stk->exclude_ix = group->nr;
1412                 stk->ucd = untracked;
1413                 pl = add_pattern_list(dir, EXC_DIRS, NULL);
1414                 strbuf_add(&dir->basebuf, base + current, stk->baselen - current);
1415                 assert(stk->baselen == dir->basebuf.len);
1416
1417                 /* Abort if the directory is excluded */
1418                 if (stk->baselen) {
1419                         int dt = DT_DIR;
1420                         dir->basebuf.buf[stk->baselen - 1] = 0;
1421                         dir->pattern = last_matching_pattern_from_lists(dir,
1422                                                                         istate,
1423                                 dir->basebuf.buf, stk->baselen - 1,
1424                                 dir->basebuf.buf + current, &dt);
1425                         dir->basebuf.buf[stk->baselen - 1] = '/';
1426                         if (dir->pattern &&
1427                             dir->pattern->flags & PATTERN_FLAG_NEGATIVE)
1428                                 dir->pattern = NULL;
1429                         if (dir->pattern) {
1430                                 dir->exclude_stack = stk;
1431                                 return;
1432                         }
1433                 }
1434
1435                 /* Try to read per-directory file */
1436                 oidclr(&oid_stat.oid);
1437                 oid_stat.valid = 0;
1438                 if (dir->exclude_per_dir &&
1439                     /*
1440                      * If we know that no files have been added in
1441                      * this directory (i.e. valid_cached_dir() has
1442                      * been executed and set untracked->valid) ..
1443                      */
1444                     (!untracked || !untracked->valid ||
1445                      /*
1446                       * .. and .gitignore does not exist before
1447                       * (i.e. null exclude_oid). Then we can skip
1448                       * loading .gitignore, which would result in
1449                       * ENOENT anyway.
1450                       */
1451                      !is_null_oid(&untracked->exclude_oid))) {
1452                         /*
1453                          * dir->basebuf gets reused by the traversal, but we
1454                          * need fname to remain unchanged to ensure the src
1455                          * member of each struct path_pattern correctly
1456                          * back-references its source file.  Other invocations
1457                          * of add_pattern_list provide stable strings, so we
1458                          * strbuf_detach() and free() here in the caller.
1459                          */
1460                         struct strbuf sb = STRBUF_INIT;
1461                         strbuf_addbuf(&sb, &dir->basebuf);
1462                         strbuf_addstr(&sb, dir->exclude_per_dir);
1463                         pl->src = strbuf_detach(&sb, NULL);
1464                         add_patterns(pl->src, pl->src, stk->baselen, pl, istate,
1465                                      untracked ? &oid_stat : NULL);
1466                 }
1467                 /*
1468                  * NEEDSWORK: when untracked cache is enabled, prep_exclude()
1469                  * will first be called in valid_cached_dir() then maybe many
1470                  * times more in last_matching_pattern(). When the cache is
1471                  * used, last_matching_pattern() will not be called and
1472                  * reading .gitignore content will be a waste.
1473                  *
1474                  * So when it's called by valid_cached_dir() and we can get
1475                  * .gitignore SHA-1 from the index (i.e. .gitignore is not
1476                  * modified on work tree), we could delay reading the
1477                  * .gitignore content until we absolutely need it in
1478                  * last_matching_pattern(). Be careful about ignore rule
1479                  * order, though, if you do that.
1480                  */
1481                 if (untracked &&
1482                     !oideq(&oid_stat.oid, &untracked->exclude_oid)) {
1483                         invalidate_gitignore(dir->untracked, untracked);
1484                         oidcpy(&untracked->exclude_oid, &oid_stat.oid);
1485                 }
1486                 dir->exclude_stack = stk;
1487                 current = stk->baselen;
1488         }
1489         strbuf_setlen(&dir->basebuf, baselen);
1490 }
1491
1492 /*
1493  * Loads the exclude lists for the directory containing pathname, then
1494  * scans all exclude lists to determine whether pathname is excluded.
1495  * Returns the exclude_list element which matched, or NULL for
1496  * undecided.
1497  */
1498 struct path_pattern *last_matching_pattern(struct dir_struct *dir,
1499                                       struct index_state *istate,
1500                                       const char *pathname,
1501                                       int *dtype_p)
1502 {
1503         int pathlen = strlen(pathname);
1504         const char *basename = strrchr(pathname, '/');
1505         basename = (basename) ? basename+1 : pathname;
1506
1507         prep_exclude(dir, istate, pathname, basename-pathname);
1508
1509         if (dir->pattern)
1510                 return dir->pattern;
1511
1512         return last_matching_pattern_from_lists(dir, istate, pathname, pathlen,
1513                         basename, dtype_p);
1514 }
1515
1516 /*
1517  * Loads the exclude lists for the directory containing pathname, then
1518  * scans all exclude lists to determine whether pathname is excluded.
1519  * Returns 1 if true, otherwise 0.
1520  */
1521 int is_excluded(struct dir_struct *dir, struct index_state *istate,
1522                 const char *pathname, int *dtype_p)
1523 {
1524         struct path_pattern *pattern =
1525                 last_matching_pattern(dir, istate, pathname, dtype_p);
1526         if (pattern)
1527                 return pattern->flags & PATTERN_FLAG_NEGATIVE ? 0 : 1;
1528         return 0;
1529 }
1530
1531 static struct dir_entry *dir_entry_new(const char *pathname, int len)
1532 {
1533         struct dir_entry *ent;
1534
1535         FLEX_ALLOC_MEM(ent, name, pathname, len);
1536         ent->len = len;
1537         return ent;
1538 }
1539
1540 static struct dir_entry *dir_add_name(struct dir_struct *dir,
1541                                       struct index_state *istate,
1542                                       const char *pathname, int len)
1543 {
1544         if (index_file_exists(istate, pathname, len, ignore_case))
1545                 return NULL;
1546
1547         ALLOC_GROW(dir->entries, dir->nr+1, dir->alloc);
1548         return dir->entries[dir->nr++] = dir_entry_new(pathname, len);
1549 }
1550
1551 struct dir_entry *dir_add_ignored(struct dir_struct *dir,
1552                                   struct index_state *istate,
1553                                   const char *pathname, int len)
1554 {
1555         if (!index_name_is_other(istate, pathname, len))
1556                 return NULL;
1557
1558         ALLOC_GROW(dir->ignored, dir->ignored_nr+1, dir->ignored_alloc);
1559         return dir->ignored[dir->ignored_nr++] = dir_entry_new(pathname, len);
1560 }
1561
1562 enum exist_status {
1563         index_nonexistent = 0,
1564         index_directory,
1565         index_gitdir
1566 };
1567
1568 /*
1569  * Do not use the alphabetically sorted index to look up
1570  * the directory name; instead, use the case insensitive
1571  * directory hash.
1572  */
1573 static enum exist_status directory_exists_in_index_icase(struct index_state *istate,
1574                                                          const char *dirname, int len)
1575 {
1576         struct cache_entry *ce;
1577
1578         if (index_dir_exists(istate, dirname, len))
1579                 return index_directory;
1580
1581         ce = index_file_exists(istate, dirname, len, ignore_case);
1582         if (ce && S_ISGITLINK(ce->ce_mode))
1583                 return index_gitdir;
1584
1585         return index_nonexistent;
1586 }
1587
1588 /*
1589  * The index sorts alphabetically by entry name, which
1590  * means that a gitlink sorts as '\0' at the end, while
1591  * a directory (which is defined not as an entry, but as
1592  * the files it contains) will sort with the '/' at the
1593  * end.
1594  */
1595 static enum exist_status directory_exists_in_index(struct index_state *istate,
1596                                                    const char *dirname, int len)
1597 {
1598         int pos;
1599
1600         if (ignore_case)
1601                 return directory_exists_in_index_icase(istate, dirname, len);
1602
1603         pos = index_name_pos(istate, dirname, len);
1604         if (pos < 0)
1605                 pos = -pos-1;
1606         while (pos < istate->cache_nr) {
1607                 const struct cache_entry *ce = istate->cache[pos++];
1608                 unsigned char endchar;
1609
1610                 if (strncmp(ce->name, dirname, len))
1611                         break;
1612                 endchar = ce->name[len];
1613                 if (endchar > '/')
1614                         break;
1615                 if (endchar == '/')
1616                         return index_directory;
1617                 if (!endchar && S_ISGITLINK(ce->ce_mode))
1618                         return index_gitdir;
1619         }
1620         return index_nonexistent;
1621 }
1622
1623 /*
1624  * When we find a directory when traversing the filesystem, we
1625  * have three distinct cases:
1626  *
1627  *  - ignore it
1628  *  - see it as a directory
1629  *  - recurse into it
1630  *
1631  * and which one we choose depends on a combination of existing
1632  * git index contents and the flags passed into the directory
1633  * traversal routine.
1634  *
1635  * Case 1: If we *already* have entries in the index under that
1636  * directory name, we always recurse into the directory to see
1637  * all the files.
1638  *
1639  * Case 2: If we *already* have that directory name as a gitlink,
1640  * we always continue to see it as a gitlink, regardless of whether
1641  * there is an actual git directory there or not (it might not
1642  * be checked out as a subproject!)
1643  *
1644  * Case 3: if we didn't have it in the index previously, we
1645  * have a few sub-cases:
1646  *
1647  *  (a) if "show_other_directories" is true, we show it as
1648  *      just a directory, unless "hide_empty_directories" is
1649  *      also true, in which case we need to check if it contains any
1650  *      untracked and / or ignored files.
1651  *  (b) if it looks like a git directory, and we don't have
1652  *      'no_gitlinks' set we treat it as a gitlink, and show it
1653  *      as a directory.
1654  *  (c) otherwise, we recurse into it.
1655  */
1656 static enum path_treatment treat_directory(struct dir_struct *dir,
1657         struct index_state *istate,
1658         struct untracked_cache_dir *untracked,
1659         const char *dirname, int len, int baselen, int exclude,
1660         const struct pathspec *pathspec)
1661 {
1662         int nested_repo = 0;
1663
1664         /* The "len-1" is to strip the final '/' */
1665         switch (directory_exists_in_index(istate, dirname, len-1)) {
1666         case index_directory:
1667                 return path_recurse;
1668
1669         case index_gitdir:
1670                 return path_none;
1671
1672         case index_nonexistent:
1673                 if ((dir->flags & DIR_SKIP_NESTED_GIT) ||
1674                     !(dir->flags & DIR_NO_GITLINKS)) {
1675                         struct strbuf sb = STRBUF_INIT;
1676                         strbuf_addstr(&sb, dirname);
1677                         nested_repo = is_nonbare_repository_dir(&sb);
1678                         strbuf_release(&sb);
1679                 }
1680                 if (nested_repo)
1681                         return ((dir->flags & DIR_SKIP_NESTED_GIT) ? path_none :
1682                                 (exclude ? path_excluded : path_untracked));
1683
1684                 if (dir->flags & DIR_SHOW_OTHER_DIRECTORIES)
1685                         break;
1686                 if (exclude &&
1687                         (dir->flags & DIR_SHOW_IGNORED_TOO) &&
1688                         (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING)) {
1689
1690                         /*
1691                          * This is an excluded directory and we are
1692                          * showing ignored paths that match an exclude
1693                          * pattern.  (e.g. show directory as ignored
1694                          * only if it matches an exclude pattern).
1695                          * This path will either be 'path_excluded`
1696                          * (if we are showing empty directories or if
1697                          * the directory is not empty), or will be
1698                          * 'path_none' (empty directory, and we are
1699                          * not showing empty directories).
1700                          */
1701                         if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
1702                                 return path_excluded;
1703
1704                         if (read_directory_recursive(dir, istate, dirname, len,
1705                                                      untracked, 1, 1, pathspec) == path_excluded)
1706                                 return path_excluded;
1707
1708                         return path_none;
1709                 }
1710                 return path_recurse;
1711         }
1712
1713         /* This is the "show_other_directories" case */
1714
1715         if (!(dir->flags & DIR_HIDE_EMPTY_DIRECTORIES))
1716                 return exclude ? path_excluded : path_untracked;
1717
1718         untracked = lookup_untracked(dir->untracked, untracked,
1719                                      dirname + baselen, len - baselen);
1720
1721         /*
1722          * If this is an excluded directory, then we only need to check if
1723          * the directory contains any files.
1724          */
1725         return read_directory_recursive(dir, istate, dirname, len,
1726                                         untracked, 1, exclude, pathspec);
1727 }
1728
1729 /*
1730  * This is an inexact early pruning of any recursive directory
1731  * reading - if the path cannot possibly be in the pathspec,
1732  * return true, and we'll skip it early.
1733  */
1734 static int simplify_away(const char *path, int pathlen,
1735                          const struct pathspec *pathspec)
1736 {
1737         int i;
1738
1739         if (!pathspec || !pathspec->nr)
1740                 return 0;
1741
1742         GUARD_PATHSPEC(pathspec,
1743                        PATHSPEC_FROMTOP |
1744                        PATHSPEC_MAXDEPTH |
1745                        PATHSPEC_LITERAL |
1746                        PATHSPEC_GLOB |
1747                        PATHSPEC_ICASE |
1748                        PATHSPEC_EXCLUDE |
1749                        PATHSPEC_ATTR);
1750
1751         for (i = 0; i < pathspec->nr; i++) {
1752                 const struct pathspec_item *item = &pathspec->items[i];
1753                 int len = item->nowildcard_len;
1754
1755                 if (len > pathlen)
1756                         len = pathlen;
1757                 if (!ps_strncmp(item, item->match, path, len))
1758                         return 0;
1759         }
1760
1761         return 1;
1762 }
1763
1764 /*
1765  * This function tells us whether an excluded path matches a
1766  * list of "interesting" pathspecs. That is, whether a path matched
1767  * by any of the pathspecs could possibly be ignored by excluding
1768  * the specified path. This can happen if:
1769  *
1770  *   1. the path is mentioned explicitly in the pathspec
1771  *
1772  *   2. the path is a directory prefix of some element in the
1773  *      pathspec
1774  */
1775 static int exclude_matches_pathspec(const char *path, int pathlen,
1776                                     const struct pathspec *pathspec)
1777 {
1778         int i;
1779
1780         if (!pathspec || !pathspec->nr)
1781                 return 0;
1782
1783         GUARD_PATHSPEC(pathspec,
1784                        PATHSPEC_FROMTOP |
1785                        PATHSPEC_MAXDEPTH |
1786                        PATHSPEC_LITERAL |
1787                        PATHSPEC_GLOB |
1788                        PATHSPEC_ICASE |
1789                        PATHSPEC_EXCLUDE);
1790
1791         for (i = 0; i < pathspec->nr; i++) {
1792                 const struct pathspec_item *item = &pathspec->items[i];
1793                 int len = item->nowildcard_len;
1794
1795                 if (len == pathlen &&
1796                     !ps_strncmp(item, item->match, path, pathlen))
1797                         return 1;
1798                 if (len > pathlen &&
1799                     item->match[pathlen] == '/' &&
1800                     !ps_strncmp(item, item->match, path, pathlen))
1801                         return 1;
1802         }
1803         return 0;
1804 }
1805
1806 static int get_index_dtype(struct index_state *istate,
1807                            const char *path, int len)
1808 {
1809         int pos;
1810         const struct cache_entry *ce;
1811
1812         ce = index_file_exists(istate, path, len, 0);
1813         if (ce) {
1814                 if (!ce_uptodate(ce))
1815                         return DT_UNKNOWN;
1816                 if (S_ISGITLINK(ce->ce_mode))
1817                         return DT_DIR;
1818                 /*
1819                  * Nobody actually cares about the
1820                  * difference between DT_LNK and DT_REG
1821                  */
1822                 return DT_REG;
1823         }
1824
1825         /* Try to look it up as a directory */
1826         pos = index_name_pos(istate, path, len);
1827         if (pos >= 0)
1828                 return DT_UNKNOWN;
1829         pos = -pos-1;
1830         while (pos < istate->cache_nr) {
1831                 ce = istate->cache[pos++];
1832                 if (strncmp(ce->name, path, len))
1833                         break;
1834                 if (ce->name[len] > '/')
1835                         break;
1836                 if (ce->name[len] < '/')
1837                         continue;
1838                 if (!ce_uptodate(ce))
1839                         break;  /* continue? */
1840                 return DT_DIR;
1841         }
1842         return DT_UNKNOWN;
1843 }
1844
1845 static int resolve_dtype(int dtype, struct index_state *istate,
1846                          const char *path, int len)
1847 {
1848         struct stat st;
1849
1850         if (dtype != DT_UNKNOWN)
1851                 return dtype;
1852         dtype = get_index_dtype(istate, path, len);
1853         if (dtype != DT_UNKNOWN)
1854                 return dtype;
1855         if (lstat(path, &st))
1856                 return dtype;
1857         if (S_ISREG(st.st_mode))
1858                 return DT_REG;
1859         if (S_ISDIR(st.st_mode))
1860                 return DT_DIR;
1861         if (S_ISLNK(st.st_mode))
1862                 return DT_LNK;
1863         return dtype;
1864 }
1865
1866 static enum path_treatment treat_one_path(struct dir_struct *dir,
1867                                           struct untracked_cache_dir *untracked,
1868                                           struct index_state *istate,
1869                                           struct strbuf *path,
1870                                           int baselen,
1871                                           const struct pathspec *pathspec,
1872                                           int dtype)
1873 {
1874         int exclude;
1875         int has_path_in_index = !!index_file_exists(istate, path->buf, path->len, ignore_case);
1876         enum path_treatment path_treatment;
1877
1878         dtype = resolve_dtype(dtype, istate, path->buf, path->len);
1879
1880         /* Always exclude indexed files */
1881         if (dtype != DT_DIR && has_path_in_index)
1882                 return path_none;
1883
1884         /*
1885          * When we are looking at a directory P in the working tree,
1886          * there are three cases:
1887          *
1888          * (1) P exists in the index.  Everything inside the directory P in
1889          * the working tree needs to go when P is checked out from the
1890          * index.
1891          *
1892          * (2) P does not exist in the index, but there is P/Q in the index.
1893          * We know P will stay a directory when we check out the contents
1894          * of the index, but we do not know yet if there is a directory
1895          * P/Q in the working tree to be killed, so we need to recurse.
1896          *
1897          * (3) P does not exist in the index, and there is no P/Q in the index
1898          * to require P to be a directory, either.  Only in this case, we
1899          * know that everything inside P will not be killed without
1900          * recursing.
1901          */
1902         if ((dir->flags & DIR_COLLECT_KILLED_ONLY) &&
1903             (dtype == DT_DIR) &&
1904             !has_path_in_index &&
1905             (directory_exists_in_index(istate, path->buf, path->len) == index_nonexistent))
1906                 return path_none;
1907
1908         exclude = is_excluded(dir, istate, path->buf, &dtype);
1909
1910         /*
1911          * Excluded? If we don't explicitly want to show
1912          * ignored files, ignore it
1913          */
1914         if (exclude && !(dir->flags & (DIR_SHOW_IGNORED|DIR_SHOW_IGNORED_TOO)))
1915                 return path_excluded;
1916
1917         switch (dtype) {
1918         default:
1919                 return path_none;
1920         case DT_DIR:
1921                 strbuf_addch(path, '/');
1922                 path_treatment = treat_directory(dir, istate, untracked,
1923                                                  path->buf, path->len,
1924                                                  baselen, exclude, pathspec);
1925                 /*
1926                  * If 1) we only want to return directories that
1927                  * match an exclude pattern and 2) this directory does
1928                  * not match an exclude pattern but all of its
1929                  * contents are excluded, then indicate that we should
1930                  * recurse into this directory (instead of marking the
1931                  * directory itself as an ignored path).
1932                  */
1933                 if (!exclude &&
1934                     path_treatment == path_excluded &&
1935                     (dir->flags & DIR_SHOW_IGNORED_TOO) &&
1936                     (dir->flags & DIR_SHOW_IGNORED_TOO_MODE_MATCHING))
1937                         return path_recurse;
1938                 return path_treatment;
1939         case DT_REG:
1940         case DT_LNK:
1941                 return exclude ? path_excluded : path_untracked;
1942         }
1943 }
1944
1945 static enum path_treatment treat_path_fast(struct dir_struct *dir,
1946                                            struct untracked_cache_dir *untracked,
1947                                            struct cached_dir *cdir,
1948                                            struct index_state *istate,
1949                                            struct strbuf *path,
1950                                            int baselen,
1951                                            const struct pathspec *pathspec)
1952 {
1953         strbuf_setlen(path, baselen);
1954         if (!cdir->ucd) {
1955                 strbuf_addstr(path, cdir->file);
1956                 return path_untracked;
1957         }
1958         strbuf_addstr(path, cdir->ucd->name);
1959         /* treat_one_path() does this before it calls treat_directory() */
1960         strbuf_complete(path, '/');
1961         if (cdir->ucd->check_only)
1962                 /*
1963                  * check_only is set as a result of treat_directory() getting
1964                  * to its bottom. Verify again the same set of directories
1965                  * with check_only set.
1966                  */
1967                 return read_directory_recursive(dir, istate, path->buf, path->len,
1968                                                 cdir->ucd, 1, 0, pathspec);
1969         /*
1970          * We get path_recurse in the first run when
1971          * directory_exists_in_index() returns index_nonexistent. We
1972          * are sure that new changes in the index does not impact the
1973          * outcome. Return now.
1974          */
1975         return path_recurse;
1976 }
1977
1978 static enum path_treatment treat_path(struct dir_struct *dir,
1979                                       struct untracked_cache_dir *untracked,
1980                                       struct cached_dir *cdir,
1981                                       struct index_state *istate,
1982                                       struct strbuf *path,
1983                                       int baselen,
1984                                       const struct pathspec *pathspec)
1985 {
1986         if (!cdir->d_name)
1987                 return treat_path_fast(dir, untracked, cdir, istate, path,
1988                                        baselen, pathspec);
1989         if (is_dot_or_dotdot(cdir->d_name) || !fspathcmp(cdir->d_name, ".git"))
1990                 return path_none;
1991         strbuf_setlen(path, baselen);
1992         strbuf_addstr(path, cdir->d_name);
1993         if (simplify_away(path->buf, path->len, pathspec))
1994                 return path_none;
1995
1996         return treat_one_path(dir, untracked, istate, path, baselen, pathspec,
1997                               cdir->d_type);
1998 }
1999
2000 static void add_untracked(struct untracked_cache_dir *dir, const char *name)
2001 {
2002         if (!dir)
2003                 return;
2004         ALLOC_GROW(dir->untracked, dir->untracked_nr + 1,
2005                    dir->untracked_alloc);
2006         dir->untracked[dir->untracked_nr++] = xstrdup(name);
2007 }
2008
2009 static int valid_cached_dir(struct dir_struct *dir,
2010                             struct untracked_cache_dir *untracked,
2011                             struct index_state *istate,
2012                             struct strbuf *path,
2013                             int check_only)
2014 {
2015         struct stat st;
2016
2017         if (!untracked)
2018                 return 0;
2019
2020         /*
2021          * With fsmonitor, we can trust the untracked cache's valid field.
2022          */
2023         refresh_fsmonitor(istate);
2024         if (!(dir->untracked->use_fsmonitor && untracked->valid)) {
2025                 if (lstat(path->len ? path->buf : ".", &st)) {
2026                         memset(&untracked->stat_data, 0, sizeof(untracked->stat_data));
2027                         return 0;
2028                 }
2029                 if (!untracked->valid ||
2030                         match_stat_data_racy(istate, &untracked->stat_data, &st)) {
2031                         fill_stat_data(&untracked->stat_data, &st);
2032                         return 0;
2033                 }
2034         }
2035
2036         if (untracked->check_only != !!check_only)
2037                 return 0;
2038
2039         /*
2040          * prep_exclude will be called eventually on this directory,
2041          * but it's called much later in last_matching_pattern(). We
2042          * need it now to determine the validity of the cache for this
2043          * path. The next calls will be nearly no-op, the way
2044          * prep_exclude() is designed.
2045          */
2046         if (path->len && path->buf[path->len - 1] != '/') {
2047                 strbuf_addch(path, '/');
2048                 prep_exclude(dir, istate, path->buf, path->len);
2049                 strbuf_setlen(path, path->len - 1);
2050         } else
2051                 prep_exclude(dir, istate, path->buf, path->len);
2052
2053         /* hopefully prep_exclude() haven't invalidated this entry... */
2054         return untracked->valid;
2055 }
2056
2057 static int open_cached_dir(struct cached_dir *cdir,
2058                            struct dir_struct *dir,
2059                            struct untracked_cache_dir *untracked,
2060                            struct index_state *istate,
2061                            struct strbuf *path,
2062                            int check_only)
2063 {
2064         const char *c_path;
2065
2066         memset(cdir, 0, sizeof(*cdir));
2067         cdir->untracked = untracked;
2068         if (valid_cached_dir(dir, untracked, istate, path, check_only))
2069                 return 0;
2070         c_path = path->len ? path->buf : ".";
2071         cdir->fdir = opendir(c_path);
2072         if (!cdir->fdir)
2073                 warning_errno(_("could not open directory '%s'"), c_path);
2074         if (dir->untracked) {
2075                 invalidate_directory(dir->untracked, untracked);
2076                 dir->untracked->dir_opened++;
2077         }
2078         if (!cdir->fdir)
2079                 return -1;
2080         return 0;
2081 }
2082
2083 static int read_cached_dir(struct cached_dir *cdir)
2084 {
2085         struct dirent *de;
2086
2087         if (cdir->fdir) {
2088                 de = readdir(cdir->fdir);
2089                 if (!de) {
2090                         cdir->d_name = NULL;
2091                         cdir->d_type = DT_UNKNOWN;
2092                         return -1;
2093                 }
2094                 cdir->d_name = de->d_name;
2095                 cdir->d_type = DTYPE(de);
2096                 return 0;
2097         }
2098         while (cdir->nr_dirs < cdir->untracked->dirs_nr) {
2099                 struct untracked_cache_dir *d = cdir->untracked->dirs[cdir->nr_dirs];
2100                 if (!d->recurse) {
2101                         cdir->nr_dirs++;
2102                         continue;
2103                 }
2104                 cdir->ucd = d;
2105                 cdir->nr_dirs++;
2106                 return 0;
2107         }
2108         cdir->ucd = NULL;
2109         if (cdir->nr_files < cdir->untracked->untracked_nr) {
2110                 struct untracked_cache_dir *d = cdir->untracked;
2111                 cdir->file = d->untracked[cdir->nr_files++];
2112                 return 0;
2113         }
2114         return -1;
2115 }
2116
2117 static void close_cached_dir(struct cached_dir *cdir)
2118 {
2119         if (cdir->fdir)
2120                 closedir(cdir->fdir);
2121         /*
2122          * We have gone through this directory and found no untracked
2123          * entries. Mark it valid.
2124          */
2125         if (cdir->untracked) {
2126                 cdir->untracked->valid = 1;
2127                 cdir->untracked->recurse = 1;
2128         }
2129 }
2130
2131 static void add_path_to_appropriate_result_list(struct dir_struct *dir,
2132         struct untracked_cache_dir *untracked,
2133         struct cached_dir *cdir,
2134         struct index_state *istate,
2135         struct strbuf *path,
2136         int baselen,
2137         const struct pathspec *pathspec,
2138         enum path_treatment state)
2139 {
2140         /* add the path to the appropriate result list */
2141         switch (state) {
2142         case path_excluded:
2143                 if (dir->flags & DIR_SHOW_IGNORED)
2144                         dir_add_name(dir, istate, path->buf, path->len);
2145                 else if ((dir->flags & DIR_SHOW_IGNORED_TOO) ||
2146                         ((dir->flags & DIR_COLLECT_IGNORED) &&
2147                         exclude_matches_pathspec(path->buf, path->len,
2148                                                  pathspec)))
2149                         dir_add_ignored(dir, istate, path->buf, path->len);
2150                 break;
2151
2152         case path_untracked:
2153                 if (dir->flags & DIR_SHOW_IGNORED)
2154                         break;
2155                 dir_add_name(dir, istate, path->buf, path->len);
2156                 if (cdir->fdir)
2157                         add_untracked(untracked, path->buf + baselen);
2158                 break;
2159
2160         default:
2161                 break;
2162         }
2163 }
2164
2165 /*
2166  * Read a directory tree. We currently ignore anything but
2167  * directories, regular files and symlinks. That's because git
2168  * doesn't handle them at all yet. Maybe that will change some
2169  * day.
2170  *
2171  * Also, we ignore the name ".git" (even if it is not a directory).
2172  * That likely will not change.
2173  *
2174  * If 'stop_at_first_file' is specified, 'path_excluded' is returned
2175  * to signal that a file was found. This is the least significant value that
2176  * indicates that a file was encountered that does not depend on the order of
2177  * whether an untracked or exluded path was encountered first.
2178  *
2179  * Returns the most significant path_treatment value encountered in the scan.
2180  * If 'stop_at_first_file' is specified, `path_excluded` is the most
2181  * significant path_treatment value that will be returned.
2182  */
2183
2184 static enum path_treatment read_directory_recursive(struct dir_struct *dir,
2185         struct index_state *istate, const char *base, int baselen,
2186         struct untracked_cache_dir *untracked, int check_only,
2187         int stop_at_first_file, const struct pathspec *pathspec)
2188 {
2189         /*
2190          * WARNING WARNING WARNING:
2191          *
2192          * Any updates to the traversal logic here may need corresponding
2193          * updates in treat_leading_path().  See the commit message for the
2194          * commit adding this warning as well as the commit preceding it
2195          * for details.
2196          */
2197
2198         struct cached_dir cdir;
2199         enum path_treatment state, subdir_state, dir_state = path_none;
2200         struct strbuf path = STRBUF_INIT;
2201
2202         strbuf_add(&path, base, baselen);
2203
2204         if (open_cached_dir(&cdir, dir, untracked, istate, &path, check_only))
2205                 goto out;
2206
2207         if (untracked)
2208                 untracked->check_only = !!check_only;
2209
2210         while (!read_cached_dir(&cdir)) {
2211                 /* check how the file or directory should be treated */
2212                 state = treat_path(dir, untracked, &cdir, istate, &path,
2213                                    baselen, pathspec);
2214
2215                 if (state > dir_state)
2216                         dir_state = state;
2217
2218                 /* recurse into subdir if instructed by treat_path */
2219                 if ((state == path_recurse) ||
2220                         ((state == path_untracked) &&
2221                          (resolve_dtype(cdir.d_type, istate, path.buf, path.len) == DT_DIR) &&
2222                          ((dir->flags & DIR_SHOW_IGNORED_TOO) ||
2223                           (pathspec &&
2224                            do_match_pathspec(istate, pathspec, path.buf, path.len,
2225                                              baselen, NULL, DO_MATCH_LEADING_PATHSPEC) == MATCHED_RECURSIVELY_LEADING_PATHSPEC)))) {
2226                         struct untracked_cache_dir *ud;
2227                         ud = lookup_untracked(dir->untracked, untracked,
2228                                               path.buf + baselen,
2229                                               path.len - baselen);
2230                         subdir_state =
2231                                 read_directory_recursive(dir, istate, path.buf,
2232                                                          path.len, ud,
2233                                                          check_only, stop_at_first_file, pathspec);
2234                         if (subdir_state > dir_state)
2235                                 dir_state = subdir_state;
2236
2237                         if (pathspec &&
2238                             !match_pathspec(istate, pathspec, path.buf, path.len,
2239                                             0 /* prefix */, NULL,
2240                                             0 /* do NOT special case dirs */))
2241                                 state = path_none;
2242                 }
2243
2244                 if (check_only) {
2245                         if (stop_at_first_file) {
2246                                 /*
2247                                  * If stopping at first file, then
2248                                  * signal that a file was found by
2249                                  * returning `path_excluded`. This is
2250                                  * to return a consistent value
2251                                  * regardless of whether an ignored or
2252                                  * excluded file happened to be
2253                                  * encountered 1st.
2254                                  *
2255                                  * In current usage, the
2256                                  * `stop_at_first_file` is passed when
2257                                  * an ancestor directory has matched
2258                                  * an exclude pattern, so any found
2259                                  * files will be excluded.
2260                                  */
2261                                 if (dir_state >= path_excluded) {
2262                                         dir_state = path_excluded;
2263                                         break;
2264                                 }
2265                         }
2266
2267                         /* abort early if maximum state has been reached */
2268                         if (dir_state == path_untracked) {
2269                                 if (cdir.fdir)
2270                                         add_untracked(untracked, path.buf + baselen);
2271                                 break;
2272                         }
2273                         /* skip the dir_add_* part */
2274                         continue;
2275                 }
2276
2277                 add_path_to_appropriate_result_list(dir, untracked, &cdir,
2278                                                     istate, &path, baselen,
2279                                                     pathspec, state);
2280         }
2281         close_cached_dir(&cdir);
2282  out:
2283         strbuf_release(&path);
2284
2285         return dir_state;
2286 }
2287
2288 int cmp_dir_entry(const void *p1, const void *p2)
2289 {
2290         const struct dir_entry *e1 = *(const struct dir_entry **)p1;
2291         const struct dir_entry *e2 = *(const struct dir_entry **)p2;
2292
2293         return name_compare(e1->name, e1->len, e2->name, e2->len);
2294 }
2295
2296 /* check if *out lexically strictly contains *in */
2297 int check_dir_entry_contains(const struct dir_entry *out, const struct dir_entry *in)
2298 {
2299         return (out->len < in->len) &&
2300                 (out->name[out->len - 1] == '/') &&
2301                 !memcmp(out->name, in->name, out->len);
2302 }
2303
2304 static int treat_leading_path(struct dir_struct *dir,
2305                               struct index_state *istate,
2306                               const char *path, int len,
2307                               const struct pathspec *pathspec)
2308 {
2309         /*
2310          * WARNING WARNING WARNING:
2311          *
2312          * Any updates to the traversal logic here may need corresponding
2313          * updates in read_directory_recursive().  See 777b420347 (dir:
2314          * synchronize treat_leading_path() and read_directory_recursive(),
2315          * 2019-12-19) and its parent commit for details.
2316          */
2317
2318         struct strbuf sb = STRBUF_INIT;
2319         struct strbuf subdir = STRBUF_INIT;
2320         int prevlen, baselen;
2321         const char *cp;
2322         struct cached_dir cdir;
2323         enum path_treatment state = path_none;
2324
2325         /*
2326          * For each directory component of path, we are going to check whether
2327          * that path is relevant given the pathspec.  For example, if path is
2328          *    foo/bar/baz/
2329          * then we will ask treat_path() whether we should go into foo, then
2330          * whether we should go into bar, then whether baz is relevant.
2331          * Checking each is important because e.g. if path is
2332          *    .git/info/
2333          * then we need to check .git to know we shouldn't traverse it.
2334          * If the return from treat_path() is:
2335          *    * path_none, for any path, we return false.
2336          *    * path_recurse, for all path components, we return true
2337          *    * <anything else> for some intermediate component, we make sure
2338          *        to add that path to the relevant list but return false
2339          *        signifying that we shouldn't recurse into it.
2340          */
2341
2342         while (len && path[len - 1] == '/')
2343                 len--;
2344         if (!len)
2345                 return 1;
2346
2347         memset(&cdir, 0, sizeof(cdir));
2348         cdir.d_type = DT_DIR;
2349         baselen = 0;
2350         prevlen = 0;
2351         while (1) {
2352                 prevlen = baselen + !!baselen;
2353                 cp = path + prevlen;
2354                 cp = memchr(cp, '/', path + len - cp);
2355                 if (!cp)
2356                         baselen = len;
2357                 else
2358                         baselen = cp - path;
2359                 strbuf_reset(&sb);
2360                 strbuf_add(&sb, path, baselen);
2361                 if (!is_directory(sb.buf))
2362                         break;
2363                 strbuf_reset(&sb);
2364                 strbuf_add(&sb, path, prevlen);
2365                 strbuf_reset(&subdir);
2366                 strbuf_add(&subdir, path+prevlen, baselen-prevlen);
2367                 cdir.d_name = subdir.buf;
2368                 state = treat_path(dir, NULL, &cdir, istate, &sb, prevlen,
2369                                     pathspec);
2370                 if (state == path_untracked &&
2371                     resolve_dtype(cdir.d_type, istate, sb.buf, sb.len) == DT_DIR &&
2372                     (dir->flags & DIR_SHOW_IGNORED_TOO ||
2373                      do_match_pathspec(istate, pathspec, sb.buf, sb.len,
2374                                        baselen, NULL, DO_MATCH_LEADING_PATHSPEC) == MATCHED_RECURSIVELY_LEADING_PATHSPEC)) {
2375                         if (!match_pathspec(istate, pathspec, sb.buf, sb.len,
2376                                             0 /* prefix */, NULL,
2377                                             0 /* do NOT special case dirs */))
2378                                 state = path_none;
2379                         add_path_to_appropriate_result_list(dir, NULL, &cdir,
2380                                                             istate,
2381                                                             &sb, baselen,
2382                                                             pathspec, state);
2383                         state = path_recurse;
2384                 }
2385
2386                 if (state != path_recurse)
2387                         break; /* do not recurse into it */
2388                 if (len <= baselen)
2389                         break; /* finished checking */
2390         }
2391         add_path_to_appropriate_result_list(dir, NULL, &cdir, istate,
2392                                             &sb, baselen, pathspec,
2393                                             state);
2394
2395         strbuf_release(&subdir);
2396         strbuf_release(&sb);
2397         return state == path_recurse;
2398 }
2399
2400 static const char *get_ident_string(void)
2401 {
2402         static struct strbuf sb = STRBUF_INIT;
2403         struct utsname uts;
2404
2405         if (sb.len)
2406                 return sb.buf;
2407         if (uname(&uts) < 0)
2408                 die_errno(_("failed to get kernel name and information"));
2409         strbuf_addf(&sb, "Location %s, system %s", get_git_work_tree(),
2410                     uts.sysname);
2411         return sb.buf;
2412 }
2413
2414 static int ident_in_untracked(const struct untracked_cache *uc)
2415 {
2416         /*
2417          * Previous git versions may have saved many NUL separated
2418          * strings in the "ident" field, but it is insane to manage
2419          * many locations, so just take care of the first one.
2420          */
2421
2422         return !strcmp(uc->ident.buf, get_ident_string());
2423 }
2424
2425 static void set_untracked_ident(struct untracked_cache *uc)
2426 {
2427         strbuf_reset(&uc->ident);
2428         strbuf_addstr(&uc->ident, get_ident_string());
2429
2430         /*
2431          * This strbuf used to contain a list of NUL separated
2432          * strings, so save NUL too for backward compatibility.
2433          */
2434         strbuf_addch(&uc->ident, 0);
2435 }
2436
2437 static void new_untracked_cache(struct index_state *istate)
2438 {
2439         struct untracked_cache *uc = xcalloc(1, sizeof(*uc));
2440         strbuf_init(&uc->ident, 100);
2441         uc->exclude_per_dir = ".gitignore";
2442         /* should be the same flags used by git-status */
2443         uc->dir_flags = DIR_SHOW_OTHER_DIRECTORIES | DIR_HIDE_EMPTY_DIRECTORIES;
2444         set_untracked_ident(uc);
2445         istate->untracked = uc;
2446         istate->cache_changed |= UNTRACKED_CHANGED;
2447 }
2448
2449 void add_untracked_cache(struct index_state *istate)
2450 {
2451         if (!istate->untracked) {
2452                 new_untracked_cache(istate);
2453         } else {
2454                 if (!ident_in_untracked(istate->untracked)) {
2455                         free_untracked_cache(istate->untracked);
2456                         new_untracked_cache(istate);
2457                 }
2458         }
2459 }
2460
2461 void remove_untracked_cache(struct index_state *istate)
2462 {
2463         if (istate->untracked) {
2464                 free_untracked_cache(istate->untracked);
2465                 istate->untracked = NULL;
2466                 istate->cache_changed |= UNTRACKED_CHANGED;
2467         }
2468 }
2469
2470 static struct untracked_cache_dir *validate_untracked_cache(struct dir_struct *dir,
2471                                                       int base_len,
2472                                                       const struct pathspec *pathspec)
2473 {
2474         struct untracked_cache_dir *root;
2475         static int untracked_cache_disabled = -1;
2476
2477         if (!dir->untracked)
2478                 return NULL;
2479         if (untracked_cache_disabled < 0)
2480                 untracked_cache_disabled = git_env_bool("GIT_DISABLE_UNTRACKED_CACHE", 0);
2481         if (untracked_cache_disabled)
2482                 return NULL;
2483
2484         /*
2485          * We only support $GIT_DIR/info/exclude and core.excludesfile
2486          * as the global ignore rule files. Any other additions
2487          * (e.g. from command line) invalidate the cache. This
2488          * condition also catches running setup_standard_excludes()
2489          * before setting dir->untracked!
2490          */
2491         if (dir->unmanaged_exclude_files)
2492                 return NULL;
2493
2494         /*
2495          * Optimize for the main use case only: whole-tree git
2496          * status. More work involved in treat_leading_path() if we
2497          * use cache on just a subset of the worktree. pathspec
2498          * support could make the matter even worse.
2499          */
2500         if (base_len || (pathspec && pathspec->nr))
2501                 return NULL;
2502
2503         /* Different set of flags may produce different results */
2504         if (dir->flags != dir->untracked->dir_flags ||
2505             /*
2506              * See treat_directory(), case index_nonexistent. Without
2507              * this flag, we may need to also cache .git file content
2508              * for the resolve_gitlink_ref() call, which we don't.
2509              */
2510             !(dir->flags & DIR_SHOW_OTHER_DIRECTORIES) ||
2511             /* We don't support collecting ignore files */
2512             (dir->flags & (DIR_SHOW_IGNORED | DIR_SHOW_IGNORED_TOO |
2513                            DIR_COLLECT_IGNORED)))
2514                 return NULL;
2515
2516         /*
2517          * If we use .gitignore in the cache and now you change it to
2518          * .gitexclude, everything will go wrong.
2519          */
2520         if (dir->exclude_per_dir != dir->untracked->exclude_per_dir &&
2521             strcmp(dir->exclude_per_dir, dir->untracked->exclude_per_dir))
2522                 return NULL;
2523
2524         /*
2525          * EXC_CMDL is not considered in the cache. If people set it,
2526          * skip the cache.
2527          */
2528         if (dir->exclude_list_group[EXC_CMDL].nr)
2529                 return NULL;
2530
2531         if (!ident_in_untracked(dir->untracked)) {
2532                 warning(_("untracked cache is disabled on this system or location"));
2533                 return NULL;
2534         }
2535
2536         if (!dir->untracked->root) {
2537                 const int len = sizeof(*dir->untracked->root);
2538                 dir->untracked->root = xmalloc(len);
2539                 memset(dir->untracked->root, 0, len);
2540         }
2541
2542         /* Validate $GIT_DIR/info/exclude and core.excludesfile */
2543         root = dir->untracked->root;
2544         if (!oideq(&dir->ss_info_exclude.oid,
2545                    &dir->untracked->ss_info_exclude.oid)) {
2546                 invalidate_gitignore(dir->untracked, root);
2547                 dir->untracked->ss_info_exclude = dir->ss_info_exclude;
2548         }
2549         if (!oideq(&dir->ss_excludes_file.oid,
2550                    &dir->untracked->ss_excludes_file.oid)) {
2551                 invalidate_gitignore(dir->untracked, root);
2552                 dir->untracked->ss_excludes_file = dir->ss_excludes_file;
2553         }
2554
2555         /* Make sure this directory is not dropped out at saving phase */
2556         root->recurse = 1;
2557         return root;
2558 }
2559
2560 int read_directory(struct dir_struct *dir, struct index_state *istate,
2561                    const char *path, int len, const struct pathspec *pathspec)
2562 {
2563         struct untracked_cache_dir *untracked;
2564
2565         trace_performance_enter();
2566
2567         if (has_symlink_leading_path(path, len)) {
2568                 trace_performance_leave("read directory %.*s", len, path);
2569                 return dir->nr;
2570         }
2571
2572         untracked = validate_untracked_cache(dir, len, pathspec);
2573         if (!untracked)
2574                 /*
2575                  * make sure untracked cache code path is disabled,
2576                  * e.g. prep_exclude()
2577                  */
2578                 dir->untracked = NULL;
2579         if (!len || treat_leading_path(dir, istate, path, len, pathspec))
2580                 read_directory_recursive(dir, istate, path, len, untracked, 0, 0, pathspec);
2581         QSORT(dir->entries, dir->nr, cmp_dir_entry);
2582         QSORT(dir->ignored, dir->ignored_nr, cmp_dir_entry);
2583
2584         /*
2585          * If DIR_SHOW_IGNORED_TOO is set, read_directory_recursive() will
2586          * also pick up untracked contents of untracked dirs; by default
2587          * we discard these, but given DIR_KEEP_UNTRACKED_CONTENTS we do not.
2588          */
2589         if ((dir->flags & DIR_SHOW_IGNORED_TOO) &&
2590                      !(dir->flags & DIR_KEEP_UNTRACKED_CONTENTS)) {
2591                 int i, j;
2592
2593                 /* remove from dir->entries untracked contents of untracked dirs */
2594                 for (i = j = 0; j < dir->nr; j++) {
2595                         if (i &&
2596                             check_dir_entry_contains(dir->entries[i - 1], dir->entries[j])) {
2597                                 FREE_AND_NULL(dir->entries[j]);
2598                         } else {
2599                                 dir->entries[i++] = dir->entries[j];
2600                         }
2601                 }
2602
2603                 dir->nr = i;
2604         }
2605
2606         trace_performance_leave("read directory %.*s", len, path);
2607         if (dir->untracked) {
2608                 static int force_untracked_cache = -1;
2609                 static struct trace_key trace_untracked_stats = TRACE_KEY_INIT(UNTRACKED_STATS);
2610
2611                 if (force_untracked_cache < 0)
2612                         force_untracked_cache =
2613                                 git_env_bool("GIT_FORCE_UNTRACKED_CACHE", 0);
2614                 trace_printf_key(&trace_untracked_stats,
2615                                  "node creation: %u\n"
2616                                  "gitignore invalidation: %u\n"
2617                                  "directory invalidation: %u\n"
2618                                  "opendir: %u\n",
2619                                  dir->untracked->dir_created,
2620                                  dir->untracked->gitignore_invalidated,
2621                                  dir->untracked->dir_invalidated,
2622                                  dir->untracked->dir_opened);
2623                 if (force_untracked_cache &&
2624                         dir->untracked == istate->untracked &&
2625                     (dir->untracked->dir_opened ||
2626                      dir->untracked->gitignore_invalidated ||
2627                      dir->untracked->dir_invalidated))
2628                         istate->cache_changed |= UNTRACKED_CHANGED;
2629                 if (dir->untracked != istate->untracked) {
2630                         FREE_AND_NULL(dir->untracked);
2631                 }
2632         }
2633         return dir->nr;
2634 }
2635
2636 int file_exists(const char *f)
2637 {
2638         struct stat sb;
2639         return lstat(f, &sb) == 0;
2640 }
2641
2642 int repo_file_exists(struct repository *repo, const char *path)
2643 {
2644         if (repo != the_repository)
2645                 BUG("do not know how to check file existence in arbitrary repo");
2646
2647         return file_exists(path);
2648 }
2649
2650 static int cmp_icase(char a, char b)
2651 {
2652         if (a == b)
2653                 return 0;
2654         if (ignore_case)
2655                 return toupper(a) - toupper(b);
2656         return a - b;
2657 }
2658
2659 /*
2660  * Given two normalized paths (a trailing slash is ok), if subdir is
2661  * outside dir, return -1.  Otherwise return the offset in subdir that
2662  * can be used as relative path to dir.
2663  */
2664 int dir_inside_of(const char *subdir, const char *dir)
2665 {
2666         int offset = 0;
2667
2668         assert(dir && subdir && *dir && *subdir);
2669
2670         while (*dir && *subdir && !cmp_icase(*dir, *subdir)) {
2671                 dir++;
2672                 subdir++;
2673                 offset++;
2674         }
2675
2676         /* hel[p]/me vs hel[l]/yeah */
2677         if (*dir && *subdir)
2678                 return -1;
2679
2680         if (!*subdir)
2681                 return !*dir ? offset : -1; /* same dir */
2682
2683         /* foo/[b]ar vs foo/[] */
2684         if (is_dir_sep(dir[-1]))
2685                 return is_dir_sep(subdir[-1]) ? offset : -1;
2686
2687         /* foo[/]bar vs foo[] */
2688         return is_dir_sep(*subdir) ? offset + 1 : -1;
2689 }
2690
2691 int is_inside_dir(const char *dir)
2692 {
2693         char *cwd;
2694         int rc;
2695
2696         if (!dir)
2697                 return 0;
2698
2699         cwd = xgetcwd();
2700         rc = (dir_inside_of(cwd, dir) >= 0);
2701         free(cwd);
2702         return rc;
2703 }
2704
2705 int is_empty_dir(const char *path)
2706 {
2707         DIR *dir = opendir(path);
2708         struct dirent *e;
2709         int ret = 1;
2710
2711         if (!dir)
2712                 return 0;
2713
2714         while ((e = readdir(dir)) != NULL)
2715                 if (!is_dot_or_dotdot(e->d_name)) {
2716                         ret = 0;
2717                         break;
2718                 }
2719
2720         closedir(dir);
2721         return ret;
2722 }
2723
2724 static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up)
2725 {
2726         DIR *dir;
2727         struct dirent *e;
2728         int ret = 0, original_len = path->len, len, kept_down = 0;
2729         int only_empty = (flag & REMOVE_DIR_EMPTY_ONLY);
2730         int keep_toplevel = (flag & REMOVE_DIR_KEEP_TOPLEVEL);
2731         struct object_id submodule_head;
2732
2733         if ((flag & REMOVE_DIR_KEEP_NESTED_GIT) &&
2734             !resolve_gitlink_ref(path->buf, "HEAD", &submodule_head)) {
2735                 /* Do not descend and nuke a nested git work tree. */
2736                 if (kept_up)
2737                         *kept_up = 1;
2738                 return 0;
2739         }
2740
2741         flag &= ~REMOVE_DIR_KEEP_TOPLEVEL;
2742         dir = opendir(path->buf);
2743         if (!dir) {
2744                 if (errno == ENOENT)
2745                         return keep_toplevel ? -1 : 0;
2746                 else if (errno == EACCES && !keep_toplevel)
2747                         /*
2748                          * An empty dir could be removable even if it
2749                          * is unreadable:
2750                          */
2751                         return rmdir(path->buf);
2752                 else
2753                         return -1;
2754         }
2755         strbuf_complete(path, '/');
2756
2757         len = path->len;
2758         while ((e = readdir(dir)) != NULL) {
2759                 struct stat st;
2760                 if (is_dot_or_dotdot(e->d_name))
2761                         continue;
2762
2763                 strbuf_setlen(path, len);
2764                 strbuf_addstr(path, e->d_name);
2765                 if (lstat(path->buf, &st)) {
2766                         if (errno == ENOENT)
2767                                 /*
2768                                  * file disappeared, which is what we
2769                                  * wanted anyway
2770                                  */
2771                                 continue;
2772                         /* fall through */
2773                 } else if (S_ISDIR(st.st_mode)) {
2774                         if (!remove_dir_recurse(path, flag, &kept_down))
2775                                 continue; /* happy */
2776                 } else if (!only_empty &&
2777                            (!unlink(path->buf) || errno == ENOENT)) {
2778                         continue; /* happy, too */
2779                 }
2780
2781                 /* path too long, stat fails, or non-directory still exists */
2782                 ret = -1;
2783                 break;
2784         }
2785         closedir(dir);
2786
2787         strbuf_setlen(path, original_len);
2788         if (!ret && !keep_toplevel && !kept_down)
2789                 ret = (!rmdir(path->buf) || errno == ENOENT) ? 0 : -1;
2790         else if (kept_up)
2791                 /*
2792                  * report the uplevel that it is not an error that we
2793                  * did not rmdir() our directory.
2794                  */
2795                 *kept_up = !ret;
2796         return ret;
2797 }
2798
2799 int remove_dir_recursively(struct strbuf *path, int flag)
2800 {
2801         return remove_dir_recurse(path, flag, NULL);
2802 }
2803
2804 static GIT_PATH_FUNC(git_path_info_exclude, "info/exclude")
2805
2806 void setup_standard_excludes(struct dir_struct *dir)
2807 {
2808         dir->exclude_per_dir = ".gitignore";
2809
2810         /* core.excludesfile defaulting to $XDG_CONFIG_HOME/git/ignore */
2811         if (!excludes_file)
2812                 excludes_file = xdg_config_home("ignore");
2813         if (excludes_file && !access_or_warn(excludes_file, R_OK, 0))
2814                 add_patterns_from_file_1(dir, excludes_file,
2815                                          dir->untracked ? &dir->ss_excludes_file : NULL);
2816
2817         /* per repository user preference */
2818         if (startup_info->have_repository) {
2819                 const char *path = git_path_info_exclude();
2820                 if (!access_or_warn(path, R_OK, 0))
2821                         add_patterns_from_file_1(dir, path,
2822                                                  dir->untracked ? &dir->ss_info_exclude : NULL);
2823         }
2824 }
2825
2826 int remove_path(const char *name)
2827 {
2828         char *slash;
2829
2830         if (unlink(name) && !is_missing_file_error(errno))
2831                 return -1;
2832
2833         slash = strrchr(name, '/');
2834         if (slash) {
2835                 char *dirs = xstrdup(name);
2836                 slash = dirs + (slash - name);
2837                 do {
2838                         *slash = '\0';
2839                 } while (rmdir(dirs) == 0 && (slash = strrchr(dirs, '/')));
2840                 free(dirs);
2841         }
2842         return 0;
2843 }
2844
2845 /*
2846  * Frees memory within dir which was allocated for exclude lists and
2847  * the exclude_stack.  Does not free dir itself.
2848  */
2849 void clear_directory(struct dir_struct *dir)
2850 {
2851         int i, j;
2852         struct exclude_list_group *group;
2853         struct pattern_list *pl;
2854         struct exclude_stack *stk;
2855
2856         for (i = EXC_CMDL; i <= EXC_FILE; i++) {
2857                 group = &dir->exclude_list_group[i];
2858                 for (j = 0; j < group->nr; j++) {
2859                         pl = &group->pl[j];
2860                         if (i == EXC_DIRS)
2861                                 free((char *)pl->src);
2862                         clear_pattern_list(pl);
2863                 }
2864                 free(group->pl);
2865         }
2866
2867         stk = dir->exclude_stack;
2868         while (stk) {
2869                 struct exclude_stack *prev = stk->prev;
2870                 free(stk);
2871                 stk = prev;
2872         }
2873         strbuf_release(&dir->basebuf);
2874 }
2875
2876 struct ondisk_untracked_cache {
2877         struct stat_data info_exclude_stat;
2878         struct stat_data excludes_file_stat;
2879         uint32_t dir_flags;
2880 };
2881
2882 #define ouc_offset(x) offsetof(struct ondisk_untracked_cache, x)
2883
2884 struct write_data {
2885         int index;         /* number of written untracked_cache_dir */
2886         struct ewah_bitmap *check_only; /* from untracked_cache_dir */
2887         struct ewah_bitmap *valid;      /* from untracked_cache_dir */
2888         struct ewah_bitmap *sha1_valid; /* set if exclude_sha1 is not null */
2889         struct strbuf out;
2890         struct strbuf sb_stat;
2891         struct strbuf sb_sha1;
2892 };
2893
2894 static void stat_data_to_disk(struct stat_data *to, const struct stat_data *from)
2895 {
2896         to->sd_ctime.sec  = htonl(from->sd_ctime.sec);
2897         to->sd_ctime.nsec = htonl(from->sd_ctime.nsec);
2898         to->sd_mtime.sec  = htonl(from->sd_mtime.sec);
2899         to->sd_mtime.nsec = htonl(from->sd_mtime.nsec);
2900         to->sd_dev        = htonl(from->sd_dev);
2901         to->sd_ino        = htonl(from->sd_ino);
2902         to->sd_uid        = htonl(from->sd_uid);
2903         to->sd_gid        = htonl(from->sd_gid);
2904         to->sd_size       = htonl(from->sd_size);
2905 }
2906
2907 static void write_one_dir(struct untracked_cache_dir *untracked,
2908                           struct write_data *wd)
2909 {
2910         struct stat_data stat_data;
2911         struct strbuf *out = &wd->out;
2912         unsigned char intbuf[16];
2913         unsigned int intlen, value;
2914         int i = wd->index++;
2915
2916         /*
2917          * untracked_nr should be reset whenever valid is clear, but
2918          * for safety..
2919          */
2920         if (!untracked->valid) {
2921                 untracked->untracked_nr = 0;
2922                 untracked->check_only = 0;
2923         }
2924
2925         if (untracked->check_only)
2926                 ewah_set(wd->check_only, i);
2927         if (untracked->valid) {
2928                 ewah_set(wd->valid, i);
2929                 stat_data_to_disk(&stat_data, &untracked->stat_data);
2930                 strbuf_add(&wd->sb_stat, &stat_data, sizeof(stat_data));
2931         }
2932         if (!is_null_oid(&untracked->exclude_oid)) {
2933                 ewah_set(wd->sha1_valid, i);
2934                 strbuf_add(&wd->sb_sha1, untracked->exclude_oid.hash,
2935                            the_hash_algo->rawsz);
2936         }
2937
2938         intlen = encode_varint(untracked->untracked_nr, intbuf);
2939         strbuf_add(out, intbuf, intlen);
2940
2941         /* skip non-recurse directories */
2942         for (i = 0, value = 0; i < untracked->dirs_nr; i++)
2943                 if (untracked->dirs[i]->recurse)
2944                         value++;
2945         intlen = encode_varint(value, intbuf);
2946         strbuf_add(out, intbuf, intlen);
2947
2948         strbuf_add(out, untracked->name, strlen(untracked->name) + 1);
2949
2950         for (i = 0; i < untracked->untracked_nr; i++)
2951                 strbuf_add(out, untracked->untracked[i],
2952                            strlen(untracked->untracked[i]) + 1);
2953
2954         for (i = 0; i < untracked->dirs_nr; i++)
2955                 if (untracked->dirs[i]->recurse)
2956                         write_one_dir(untracked->dirs[i], wd);
2957 }
2958
2959 void write_untracked_extension(struct strbuf *out, struct untracked_cache *untracked)
2960 {
2961         struct ondisk_untracked_cache *ouc;
2962         struct write_data wd;
2963         unsigned char varbuf[16];
2964         int varint_len;
2965         const unsigned hashsz = the_hash_algo->rawsz;
2966
2967         ouc = xcalloc(1, sizeof(*ouc));
2968         stat_data_to_disk(&ouc->info_exclude_stat, &untracked->ss_info_exclude.stat);
2969         stat_data_to_disk(&ouc->excludes_file_stat, &untracked->ss_excludes_file.stat);
2970         ouc->dir_flags = htonl(untracked->dir_flags);
2971
2972         varint_len = encode_varint(untracked->ident.len, varbuf);
2973         strbuf_add(out, varbuf, varint_len);
2974         strbuf_addbuf(out, &untracked->ident);
2975
2976         strbuf_add(out, ouc, sizeof(*ouc));
2977         strbuf_add(out, untracked->ss_info_exclude.oid.hash, hashsz);
2978         strbuf_add(out, untracked->ss_excludes_file.oid.hash, hashsz);
2979         strbuf_add(out, untracked->exclude_per_dir, strlen(untracked->exclude_per_dir) + 1);
2980         FREE_AND_NULL(ouc);
2981
2982         if (!untracked->root) {
2983                 varint_len = encode_varint(0, varbuf);
2984                 strbuf_add(out, varbuf, varint_len);
2985                 return;
2986         }
2987
2988         wd.index      = 0;
2989         wd.check_only = ewah_new();
2990         wd.valid      = ewah_new();
2991         wd.sha1_valid = ewah_new();
2992         strbuf_init(&wd.out, 1024);
2993         strbuf_init(&wd.sb_stat, 1024);
2994         strbuf_init(&wd.sb_sha1, 1024);
2995         write_one_dir(untracked->root, &wd);
2996
2997         varint_len = encode_varint(wd.index, varbuf);
2998         strbuf_add(out, varbuf, varint_len);
2999         strbuf_addbuf(out, &wd.out);
3000         ewah_serialize_strbuf(wd.valid, out);
3001         ewah_serialize_strbuf(wd.check_only, out);
3002         ewah_serialize_strbuf(wd.sha1_valid, out);
3003         strbuf_addbuf(out, &wd.sb_stat);
3004         strbuf_addbuf(out, &wd.sb_sha1);
3005         strbuf_addch(out, '\0'); /* safe guard for string lists */
3006
3007         ewah_free(wd.valid);
3008         ewah_free(wd.check_only);
3009         ewah_free(wd.sha1_valid);
3010         strbuf_release(&wd.out);
3011         strbuf_release(&wd.sb_stat);
3012         strbuf_release(&wd.sb_sha1);
3013 }
3014
3015 static void free_untracked(struct untracked_cache_dir *ucd)
3016 {
3017         int i;
3018         if (!ucd)
3019                 return;
3020         for (i = 0; i < ucd->dirs_nr; i++)
3021                 free_untracked(ucd->dirs[i]);
3022         for (i = 0; i < ucd->untracked_nr; i++)
3023                 free(ucd->untracked[i]);
3024         free(ucd->untracked);
3025         free(ucd->dirs);
3026         free(ucd);
3027 }
3028
3029 void free_untracked_cache(struct untracked_cache *uc)
3030 {
3031         if (uc)
3032                 free_untracked(uc->root);
3033         free(uc);
3034 }
3035
3036 struct read_data {
3037         int index;
3038         struct untracked_cache_dir **ucd;
3039         struct ewah_bitmap *check_only;
3040         struct ewah_bitmap *valid;
3041         struct ewah_bitmap *sha1_valid;
3042         const unsigned char *data;
3043         const unsigned char *end;
3044 };
3045
3046 static void stat_data_from_disk(struct stat_data *to, const unsigned char *data)
3047 {
3048         memcpy(to, data, sizeof(*to));
3049         to->sd_ctime.sec  = ntohl(to->sd_ctime.sec);
3050         to->sd_ctime.nsec = ntohl(to->sd_ctime.nsec);
3051         to->sd_mtime.sec  = ntohl(to->sd_mtime.sec);
3052         to->sd_mtime.nsec = ntohl(to->sd_mtime.nsec);
3053         to->sd_dev        = ntohl(to->sd_dev);
3054         to->sd_ino        = ntohl(to->sd_ino);
3055         to->sd_uid        = ntohl(to->sd_uid);
3056         to->sd_gid        = ntohl(to->sd_gid);
3057         to->sd_size       = ntohl(to->sd_size);
3058 }
3059
3060 static int read_one_dir(struct untracked_cache_dir **untracked_,
3061                         struct read_data *rd)
3062 {
3063         struct untracked_cache_dir ud, *untracked;
3064         const unsigned char *data = rd->data, *end = rd->end;
3065         const unsigned char *eos;
3066         unsigned int value;
3067         int i;
3068
3069         memset(&ud, 0, sizeof(ud));
3070
3071         value = decode_varint(&data);
3072         if (data > end)
3073                 return -1;
3074         ud.recurse         = 1;
3075         ud.untracked_alloc = value;
3076         ud.untracked_nr    = value;
3077         if (ud.untracked_nr)
3078                 ALLOC_ARRAY(ud.untracked, ud.untracked_nr);
3079
3080         ud.dirs_alloc = ud.dirs_nr = decode_varint(&data);
3081         if (data > end)
3082                 return -1;
3083         ALLOC_ARRAY(ud.dirs, ud.dirs_nr);
3084
3085         eos = memchr(data, '\0', end - data);
3086         if (!eos || eos == end)
3087                 return -1;
3088
3089         *untracked_ = untracked = xmalloc(st_add3(sizeof(*untracked), eos - data, 1));
3090         memcpy(untracked, &ud, sizeof(ud));
3091         memcpy(untracked->name, data, eos - data + 1);
3092         data = eos + 1;
3093
3094         for (i = 0; i < untracked->untracked_nr; i++) {
3095                 eos = memchr(data, '\0', end - data);
3096                 if (!eos || eos == end)
3097                         return -1;
3098                 untracked->untracked[i] = xmemdupz(data, eos - data);
3099                 data = eos + 1;
3100         }
3101
3102         rd->ucd[rd->index++] = untracked;
3103         rd->data = data;
3104
3105         for (i = 0; i < untracked->dirs_nr; i++) {
3106                 if (read_one_dir(untracked->dirs + i, rd) < 0)
3107                         return -1;
3108         }
3109         return 0;
3110 }
3111
3112 static void set_check_only(size_t pos, void *cb)
3113 {
3114         struct read_data *rd = cb;
3115         struct untracked_cache_dir *ud = rd->ucd[pos];
3116         ud->check_only = 1;
3117 }
3118
3119 static void read_stat(size_t pos, void *cb)
3120 {
3121         struct read_data *rd = cb;
3122         struct untracked_cache_dir *ud = rd->ucd[pos];
3123         if (rd->data + sizeof(struct stat_data) > rd->end) {
3124                 rd->data = rd->end + 1;
3125                 return;
3126         }
3127         stat_data_from_disk(&ud->stat_data, rd->data);
3128         rd->data += sizeof(struct stat_data);
3129         ud->valid = 1;
3130 }
3131
3132 static void read_oid(size_t pos, void *cb)
3133 {
3134         struct read_data *rd = cb;
3135         struct untracked_cache_dir *ud = rd->ucd[pos];
3136         if (rd->data + the_hash_algo->rawsz > rd->end) {
3137                 rd->data = rd->end + 1;
3138                 return;
3139         }
3140         hashcpy(ud->exclude_oid.hash, rd->data);
3141         rd->data += the_hash_algo->rawsz;
3142 }
3143
3144 static void load_oid_stat(struct oid_stat *oid_stat, const unsigned char *data,
3145                           const unsigned char *sha1)
3146 {
3147         stat_data_from_disk(&oid_stat->stat, data);
3148         hashcpy(oid_stat->oid.hash, sha1);
3149         oid_stat->valid = 1;
3150 }
3151
3152 struct untracked_cache *read_untracked_extension(const void *data, unsigned long sz)
3153 {
3154         struct untracked_cache *uc;
3155         struct read_data rd;
3156         const unsigned char *next = data, *end = (const unsigned char *)data + sz;
3157         const char *ident;
3158         int ident_len;
3159         ssize_t len;
3160         const char *exclude_per_dir;
3161         const unsigned hashsz = the_hash_algo->rawsz;
3162         const unsigned offset = sizeof(struct ondisk_untracked_cache);
3163         const unsigned exclude_per_dir_offset = offset + 2 * hashsz;
3164
3165         if (sz <= 1 || end[-1] != '\0')
3166                 return NULL;
3167         end--;
3168
3169         ident_len = decode_varint(&next);
3170         if (next + ident_len > end)
3171                 return NULL;
3172         ident = (const char *)next;
3173         next += ident_len;
3174
3175         if (next + exclude_per_dir_offset + 1 > end)
3176                 return NULL;
3177
3178         uc = xcalloc(1, sizeof(*uc));
3179         strbuf_init(&uc->ident, ident_len);
3180         strbuf_add(&uc->ident, ident, ident_len);
3181         load_oid_stat(&uc->ss_info_exclude,
3182                       next + ouc_offset(info_exclude_stat),
3183                       next + offset);
3184         load_oid_stat(&uc->ss_excludes_file,
3185                       next + ouc_offset(excludes_file_stat),
3186                       next + offset + hashsz);
3187         uc->dir_flags = get_be32(next + ouc_offset(dir_flags));
3188         exclude_per_dir = (const char *)next + exclude_per_dir_offset;
3189         uc->exclude_per_dir = xstrdup(exclude_per_dir);
3190         /* NUL after exclude_per_dir is covered by sizeof(*ouc) */
3191         next += exclude_per_dir_offset + strlen(exclude_per_dir) + 1;
3192         if (next >= end)
3193                 goto done2;
3194
3195         len = decode_varint(&next);
3196         if (next > end || len == 0)
3197                 goto done2;
3198
3199         rd.valid      = ewah_new();
3200         rd.check_only = ewah_new();
3201         rd.sha1_valid = ewah_new();
3202         rd.data       = next;
3203         rd.end        = end;
3204         rd.index      = 0;
3205         ALLOC_ARRAY(rd.ucd, len);
3206
3207         if (read_one_dir(&uc->root, &rd) || rd.index != len)
3208                 goto done;
3209
3210         next = rd.data;
3211         len = ewah_read_mmap(rd.valid, next, end - next);
3212         if (len < 0)
3213                 goto done;
3214
3215         next += len;
3216         len = ewah_read_mmap(rd.check_only, next, end - next);
3217         if (len < 0)
3218                 goto done;
3219
3220         next += len;
3221         len = ewah_read_mmap(rd.sha1_valid, next, end - next);
3222         if (len < 0)
3223                 goto done;
3224
3225         ewah_each_bit(rd.check_only, set_check_only, &rd);
3226         rd.data = next + len;
3227         ewah_each_bit(rd.valid, read_stat, &rd);
3228         ewah_each_bit(rd.sha1_valid, read_oid, &rd);
3229         next = rd.data;
3230
3231 done:
3232         free(rd.ucd);
3233         ewah_free(rd.valid);
3234         ewah_free(rd.check_only);
3235         ewah_free(rd.sha1_valid);
3236 done2:
3237         if (next != end) {
3238                 free_untracked_cache(uc);
3239                 uc = NULL;
3240         }
3241         return uc;
3242 }
3243
3244 static void invalidate_one_directory(struct untracked_cache *uc,
3245                                      struct untracked_cache_dir *ucd)
3246 {
3247         uc->dir_invalidated++;
3248         ucd->valid = 0;
3249         ucd->untracked_nr = 0;
3250 }
3251
3252 /*
3253  * Normally when an entry is added or removed from a directory,
3254  * invalidating that directory is enough. No need to touch its
3255  * ancestors. When a directory is shown as "foo/bar/" in git-status
3256  * however, deleting or adding an entry may have cascading effect.
3257  *
3258  * Say the "foo/bar/file" has become untracked, we need to tell the
3259  * untracked_cache_dir of "foo" that "bar/" is not an untracked
3260  * directory any more (because "bar" is managed by foo as an untracked
3261  * "file").
3262  *
3263  * Similarly, if "foo/bar/file" moves from untracked to tracked and it
3264  * was the last untracked entry in the entire "foo", we should show
3265  * "foo/" instead. Which means we have to invalidate past "bar" up to
3266  * "foo".
3267  *
3268  * This function traverses all directories from root to leaf. If there
3269  * is a chance of one of the above cases happening, we invalidate back
3270  * to root. Otherwise we just invalidate the leaf. There may be a more
3271  * sophisticated way than checking for SHOW_OTHER_DIRECTORIES to
3272  * detect these cases and avoid unnecessary invalidation, for example,
3273  * checking for the untracked entry named "bar/" in "foo", but for now
3274  * stick to something safe and simple.
3275  */
3276 static int invalidate_one_component(struct untracked_cache *uc,
3277                                     struct untracked_cache_dir *dir,
3278                                     const char *path, int len)
3279 {
3280         const char *rest = strchr(path, '/');
3281
3282         if (rest) {
3283                 int component_len = rest - path;
3284                 struct untracked_cache_dir *d =
3285                         lookup_untracked(uc, dir, path, component_len);
3286                 int ret =
3287                         invalidate_one_component(uc, d, rest + 1,
3288                                                  len - (component_len + 1));
3289                 if (ret)
3290                         invalidate_one_directory(uc, dir);
3291                 return ret;
3292         }
3293
3294         invalidate_one_directory(uc, dir);
3295         return uc->dir_flags & DIR_SHOW_OTHER_DIRECTORIES;
3296 }
3297
3298 void untracked_cache_invalidate_path(struct index_state *istate,
3299                                      const char *path, int safe_path)
3300 {
3301         if (!istate->untracked || !istate->untracked->root)
3302                 return;
3303         if (!safe_path && !verify_path(path, 0))
3304                 return;
3305         invalidate_one_component(istate->untracked, istate->untracked->root,
3306                                  path, strlen(path));
3307 }
3308
3309 void untracked_cache_remove_from_index(struct index_state *istate,
3310                                        const char *path)
3311 {
3312         untracked_cache_invalidate_path(istate, path, 1);
3313 }
3314
3315 void untracked_cache_add_to_index(struct index_state *istate,
3316                                   const char *path)
3317 {
3318         untracked_cache_invalidate_path(istate, path, 1);
3319 }
3320
3321 static void connect_wt_gitdir_in_nested(const char *sub_worktree,
3322                                         const char *sub_gitdir)
3323 {
3324         int i;
3325         struct repository subrepo;
3326         struct strbuf sub_wt = STRBUF_INIT;
3327         struct strbuf sub_gd = STRBUF_INIT;
3328
3329         const struct submodule *sub;
3330
3331         /* If the submodule has no working tree, we can ignore it. */
3332         if (repo_init(&subrepo, sub_gitdir, sub_worktree))
3333                 return;
3334
3335         if (repo_read_index(&subrepo) < 0)
3336                 die(_("index file corrupt in repo %s"), subrepo.gitdir);
3337
3338         for (i = 0; i < subrepo.index->cache_nr; i++) {
3339                 const struct cache_entry *ce = subrepo.index->cache[i];
3340
3341                 if (!S_ISGITLINK(ce->ce_mode))
3342                         continue;
3343
3344                 while (i + 1 < subrepo.index->cache_nr &&
3345                        !strcmp(ce->name, subrepo.index->cache[i + 1]->name))
3346                         /*
3347                          * Skip entries with the same name in different stages
3348                          * to make sure an entry is returned only once.
3349                          */
3350                         i++;
3351
3352                 sub = submodule_from_path(&subrepo, &null_oid, ce->name);
3353                 if (!sub || !is_submodule_active(&subrepo, ce->name))
3354                         /* .gitmodules broken or inactive sub */
3355                         continue;
3356
3357                 strbuf_reset(&sub_wt);
3358                 strbuf_reset(&sub_gd);
3359                 strbuf_addf(&sub_wt, "%s/%s", sub_worktree, sub->path);
3360                 strbuf_addf(&sub_gd, "%s/modules/%s", sub_gitdir, sub->name);
3361
3362                 connect_work_tree_and_git_dir(sub_wt.buf, sub_gd.buf, 1);
3363         }
3364         strbuf_release(&sub_wt);
3365         strbuf_release(&sub_gd);
3366         repo_clear(&subrepo);
3367 }
3368
3369 void connect_work_tree_and_git_dir(const char *work_tree_,
3370                                    const char *git_dir_,
3371                                    int recurse_into_nested)
3372 {
3373         struct strbuf gitfile_sb = STRBUF_INIT;
3374         struct strbuf cfg_sb = STRBUF_INIT;
3375         struct strbuf rel_path = STRBUF_INIT;
3376         char *git_dir, *work_tree;
3377
3378         /* Prepare .git file */
3379         strbuf_addf(&gitfile_sb, "%s/.git", work_tree_);
3380         if (safe_create_leading_directories_const(gitfile_sb.buf))
3381                 die(_("could not create directories for %s"), gitfile_sb.buf);
3382
3383         /* Prepare config file */
3384         strbuf_addf(&cfg_sb, "%s/config", git_dir_);
3385         if (safe_create_leading_directories_const(cfg_sb.buf))
3386                 die(_("could not create directories for %s"), cfg_sb.buf);
3387
3388         git_dir = real_pathdup(git_dir_, 1);
3389         work_tree = real_pathdup(work_tree_, 1);
3390
3391         /* Write .git file */
3392         write_file(gitfile_sb.buf, "gitdir: %s",
3393                    relative_path(git_dir, work_tree, &rel_path));
3394         /* Update core.worktree setting */
3395         git_config_set_in_file(cfg_sb.buf, "core.worktree",
3396                                relative_path(work_tree, git_dir, &rel_path));
3397
3398         strbuf_release(&gitfile_sb);
3399         strbuf_release(&cfg_sb);
3400         strbuf_release(&rel_path);
3401
3402         if (recurse_into_nested)
3403                 connect_wt_gitdir_in_nested(work_tree, git_dir);
3404
3405         free(work_tree);
3406         free(git_dir);
3407 }
3408
3409 /*
3410  * Migrate the git directory of the given path from old_git_dir to new_git_dir.
3411  */
3412 void relocate_gitdir(const char *path, const char *old_git_dir, const char *new_git_dir)
3413 {
3414         if (rename(old_git_dir, new_git_dir) < 0)
3415                 die_errno(_("could not migrate git directory from '%s' to '%s'"),
3416                         old_git_dir, new_git_dir);
3417
3418         connect_work_tree_and_git_dir(path, new_git_dir, 0);
3419 }