Merge branch 'jk/maint-send-email-alias-loop'
[git] / builtin-apply.c
1 /*
2  * apply.c
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  *
6  * This applies patches on top of some (arbitrary) version of the SCM.
7  *
8  */
9 #include "cache.h"
10 #include "cache-tree.h"
11 #include "quote.h"
12 #include "blob.h"
13 #include "delta.h"
14 #include "builtin.h"
15 #include "string-list.h"
16 #include "dir.h"
17 #include "parse-options.h"
18
19 /*
20  *  --check turns on checking that the working tree matches the
21  *    files that are being modified, but doesn't apply the patch
22  *  --stat does just a diffstat, and doesn't actually apply
23  *  --numstat does numeric diffstat, and doesn't actually apply
24  *  --index-info shows the old and new index info for paths if available.
25  *  --index updates the cache as well.
26  *  --cached updates only the cache without ever touching the working tree.
27  */
28 static const char *prefix;
29 static int prefix_length = -1;
30 static int newfd = -1;
31
32 static int unidiff_zero;
33 static int p_value = 1;
34 static int p_value_known;
35 static int check_index;
36 static int update_index;
37 static int cached;
38 static int diffstat;
39 static int numstat;
40 static int summary;
41 static int check;
42 static int apply = 1;
43 static int apply_in_reverse;
44 static int apply_with_reject;
45 static int apply_verbosely;
46 static int no_add;
47 static const char *fake_ancestor;
48 static int line_termination = '\n';
49 static unsigned int p_context = UINT_MAX;
50 static const char * const apply_usage[] = {
51         "git apply [options] [<patch>...]",
52         NULL
53 };
54
55 static enum ws_error_action {
56         nowarn_ws_error,
57         warn_on_ws_error,
58         die_on_ws_error,
59         correct_ws_error,
60 } ws_error_action = warn_on_ws_error;
61 static int whitespace_error;
62 static int squelch_whitespace_errors = 5;
63 static int applied_after_fixing_ws;
64 static const char *patch_input_file;
65 static const char *root;
66 static int root_len;
67 static int read_stdin = 1;
68 static int options;
69
70 static void parse_whitespace_option(const char *option)
71 {
72         if (!option) {
73                 ws_error_action = warn_on_ws_error;
74                 return;
75         }
76         if (!strcmp(option, "warn")) {
77                 ws_error_action = warn_on_ws_error;
78                 return;
79         }
80         if (!strcmp(option, "nowarn")) {
81                 ws_error_action = nowarn_ws_error;
82                 return;
83         }
84         if (!strcmp(option, "error")) {
85                 ws_error_action = die_on_ws_error;
86                 return;
87         }
88         if (!strcmp(option, "error-all")) {
89                 ws_error_action = die_on_ws_error;
90                 squelch_whitespace_errors = 0;
91                 return;
92         }
93         if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
94                 ws_error_action = correct_ws_error;
95                 return;
96         }
97         die("unrecognized whitespace option '%s'", option);
98 }
99
100 static void set_default_whitespace_mode(const char *whitespace_option)
101 {
102         if (!whitespace_option && !apply_default_whitespace)
103                 ws_error_action = (apply ? warn_on_ws_error : nowarn_ws_error);
104 }
105
106 /*
107  * For "diff-stat" like behaviour, we keep track of the biggest change
108  * we've seen, and the longest filename. That allows us to do simple
109  * scaling.
110  */
111 static int max_change, max_len;
112
113 /*
114  * Various "current state", notably line numbers and what
115  * file (and how) we're patching right now.. The "is_xxxx"
116  * things are flags, where -1 means "don't know yet".
117  */
118 static int linenr = 1;
119
120 /*
121  * This represents one "hunk" from a patch, starting with
122  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
123  * patch text is pointed at by patch, and its byte length
124  * is stored in size.  leading and trailing are the number
125  * of context lines.
126  */
127 struct fragment {
128         unsigned long leading, trailing;
129         unsigned long oldpos, oldlines;
130         unsigned long newpos, newlines;
131         const char *patch;
132         int size;
133         int rejected;
134         struct fragment *next;
135 };
136
137 /*
138  * When dealing with a binary patch, we reuse "leading" field
139  * to store the type of the binary hunk, either deflated "delta"
140  * or deflated "literal".
141  */
142 #define binary_patch_method leading
143 #define BINARY_DELTA_DEFLATED   1
144 #define BINARY_LITERAL_DEFLATED 2
145
146 /*
147  * This represents a "patch" to a file, both metainfo changes
148  * such as creation/deletion, filemode and content changes represented
149  * as a series of fragments.
150  */
151 struct patch {
152         char *new_name, *old_name, *def_name;
153         unsigned int old_mode, new_mode;
154         int is_new, is_delete;  /* -1 = unknown, 0 = false, 1 = true */
155         int rejected;
156         unsigned ws_rule;
157         unsigned long deflate_origlen;
158         int lines_added, lines_deleted;
159         int score;
160         unsigned int is_toplevel_relative:1;
161         unsigned int inaccurate_eof:1;
162         unsigned int is_binary:1;
163         unsigned int is_copy:1;
164         unsigned int is_rename:1;
165         unsigned int recount:1;
166         struct fragment *fragments;
167         char *result;
168         size_t resultsize;
169         char old_sha1_prefix[41];
170         char new_sha1_prefix[41];
171         struct patch *next;
172 };
173
174 /*
175  * A line in a file, len-bytes long (includes the terminating LF,
176  * except for an incomplete line at the end if the file ends with
177  * one), and its contents hashes to 'hash'.
178  */
179 struct line {
180         size_t len;
181         unsigned hash : 24;
182         unsigned flag : 8;
183 #define LINE_COMMON     1
184 };
185
186 /*
187  * This represents a "file", which is an array of "lines".
188  */
189 struct image {
190         char *buf;
191         size_t len;
192         size_t nr;
193         size_t alloc;
194         struct line *line_allocated;
195         struct line *line;
196 };
197
198 /*
199  * Records filenames that have been touched, in order to handle
200  * the case where more than one patches touch the same file.
201  */
202
203 static struct string_list fn_table;
204
205 static uint32_t hash_line(const char *cp, size_t len)
206 {
207         size_t i;
208         uint32_t h;
209         for (i = 0, h = 0; i < len; i++) {
210                 if (!isspace(cp[i])) {
211                         h = h * 3 + (cp[i] & 0xff);
212                 }
213         }
214         return h;
215 }
216
217 static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
218 {
219         ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
220         img->line_allocated[img->nr].len = len;
221         img->line_allocated[img->nr].hash = hash_line(bol, len);
222         img->line_allocated[img->nr].flag = flag;
223         img->nr++;
224 }
225
226 static void prepare_image(struct image *image, char *buf, size_t len,
227                           int prepare_linetable)
228 {
229         const char *cp, *ep;
230
231         memset(image, 0, sizeof(*image));
232         image->buf = buf;
233         image->len = len;
234
235         if (!prepare_linetable)
236                 return;
237
238         ep = image->buf + image->len;
239         cp = image->buf;
240         while (cp < ep) {
241                 const char *next;
242                 for (next = cp; next < ep && *next != '\n'; next++)
243                         ;
244                 if (next < ep)
245                         next++;
246                 add_line_info(image, cp, next - cp, 0);
247                 cp = next;
248         }
249         image->line = image->line_allocated;
250 }
251
252 static void clear_image(struct image *image)
253 {
254         free(image->buf);
255         image->buf = NULL;
256         image->len = 0;
257 }
258
259 static void say_patch_name(FILE *output, const char *pre,
260                            struct patch *patch, const char *post)
261 {
262         fputs(pre, output);
263         if (patch->old_name && patch->new_name &&
264             strcmp(patch->old_name, patch->new_name)) {
265                 quote_c_style(patch->old_name, NULL, output, 0);
266                 fputs(" => ", output);
267                 quote_c_style(patch->new_name, NULL, output, 0);
268         } else {
269                 const char *n = patch->new_name;
270                 if (!n)
271                         n = patch->old_name;
272                 quote_c_style(n, NULL, output, 0);
273         }
274         fputs(post, output);
275 }
276
277 #define CHUNKSIZE (8192)
278 #define SLOP (16)
279
280 static void read_patch_file(struct strbuf *sb, int fd)
281 {
282         if (strbuf_read(sb, fd, 0) < 0)
283                 die_errno("git apply: failed to read");
284
285         /*
286          * Make sure that we have some slop in the buffer
287          * so that we can do speculative "memcmp" etc, and
288          * see to it that it is NUL-filled.
289          */
290         strbuf_grow(sb, SLOP);
291         memset(sb->buf + sb->len, 0, SLOP);
292 }
293
294 static unsigned long linelen(const char *buffer, unsigned long size)
295 {
296         unsigned long len = 0;
297         while (size--) {
298                 len++;
299                 if (*buffer++ == '\n')
300                         break;
301         }
302         return len;
303 }
304
305 static int is_dev_null(const char *str)
306 {
307         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
308 }
309
310 #define TERM_SPACE      1
311 #define TERM_TAB        2
312
313 static int name_terminate(const char *name, int namelen, int c, int terminate)
314 {
315         if (c == ' ' && !(terminate & TERM_SPACE))
316                 return 0;
317         if (c == '\t' && !(terminate & TERM_TAB))
318                 return 0;
319
320         return 1;
321 }
322
323 /* remove double slashes to make --index work with such filenames */
324 static char *squash_slash(char *name)
325 {
326         int i = 0, j = 0;
327
328         while (name[i]) {
329                 if ((name[j++] = name[i++]) == '/')
330                         while (name[i] == '/')
331                                 i++;
332         }
333         name[j] = '\0';
334         return name;
335 }
336
337 static char *find_name(const char *line, char *def, int p_value, int terminate)
338 {
339         int len;
340         const char *start = line;
341
342         if (*line == '"') {
343                 struct strbuf name = STRBUF_INIT;
344
345                 /*
346                  * Proposed "new-style" GNU patch/diff format; see
347                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
348                  */
349                 if (!unquote_c_style(&name, line, NULL)) {
350                         char *cp;
351
352                         for (cp = name.buf; p_value; p_value--) {
353                                 cp = strchr(cp, '/');
354                                 if (!cp)
355                                         break;
356                                 cp++;
357                         }
358                         if (cp) {
359                                 /* name can later be freed, so we need
360                                  * to memmove, not just return cp
361                                  */
362                                 strbuf_remove(&name, 0, cp - name.buf);
363                                 free(def);
364                                 if (root)
365                                         strbuf_insert(&name, 0, root, root_len);
366                                 return squash_slash(strbuf_detach(&name, NULL));
367                         }
368                 }
369                 strbuf_release(&name);
370         }
371
372         for (;;) {
373                 char c = *line;
374
375                 if (isspace(c)) {
376                         if (c == '\n')
377                                 break;
378                         if (name_terminate(start, line-start, c, terminate))
379                                 break;
380                 }
381                 line++;
382                 if (c == '/' && !--p_value)
383                         start = line;
384         }
385         if (!start)
386                 return squash_slash(def);
387         len = line - start;
388         if (!len)
389                 return squash_slash(def);
390
391         /*
392          * Generally we prefer the shorter name, especially
393          * if the other one is just a variation of that with
394          * something else tacked on to the end (ie "file.orig"
395          * or "file~").
396          */
397         if (def) {
398                 int deflen = strlen(def);
399                 if (deflen < len && !strncmp(start, def, deflen))
400                         return squash_slash(def);
401                 free(def);
402         }
403
404         if (root) {
405                 char *ret = xmalloc(root_len + len + 1);
406                 strcpy(ret, root);
407                 memcpy(ret + root_len, start, len);
408                 ret[root_len + len] = '\0';
409                 return squash_slash(ret);
410         }
411
412         return squash_slash(xmemdupz(start, len));
413 }
414
415 static int count_slashes(const char *cp)
416 {
417         int cnt = 0;
418         char ch;
419
420         while ((ch = *cp++))
421                 if (ch == '/')
422                         cnt++;
423         return cnt;
424 }
425
426 /*
427  * Given the string after "--- " or "+++ ", guess the appropriate
428  * p_value for the given patch.
429  */
430 static int guess_p_value(const char *nameline)
431 {
432         char *name, *cp;
433         int val = -1;
434
435         if (is_dev_null(nameline))
436                 return -1;
437         name = find_name(nameline, NULL, 0, TERM_SPACE | TERM_TAB);
438         if (!name)
439                 return -1;
440         cp = strchr(name, '/');
441         if (!cp)
442                 val = 0;
443         else if (prefix) {
444                 /*
445                  * Does it begin with "a/$our-prefix" and such?  Then this is
446                  * very likely to apply to our directory.
447                  */
448                 if (!strncmp(name, prefix, prefix_length))
449                         val = count_slashes(prefix);
450                 else {
451                         cp++;
452                         if (!strncmp(cp, prefix, prefix_length))
453                                 val = count_slashes(prefix) + 1;
454                 }
455         }
456         free(name);
457         return val;
458 }
459
460 /*
461  * Get the name etc info from the ---/+++ lines of a traditional patch header
462  *
463  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
464  * files, we can happily check the index for a match, but for creating a
465  * new file we should try to match whatever "patch" does. I have no idea.
466  */
467 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
468 {
469         char *name;
470
471         first += 4;     /* skip "--- " */
472         second += 4;    /* skip "+++ " */
473         if (!p_value_known) {
474                 int p, q;
475                 p = guess_p_value(first);
476                 q = guess_p_value(second);
477                 if (p < 0) p = q;
478                 if (0 <= p && p == q) {
479                         p_value = p;
480                         p_value_known = 1;
481                 }
482         }
483         if (is_dev_null(first)) {
484                 patch->is_new = 1;
485                 patch->is_delete = 0;
486                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
487                 patch->new_name = name;
488         } else if (is_dev_null(second)) {
489                 patch->is_new = 0;
490                 patch->is_delete = 1;
491                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
492                 patch->old_name = name;
493         } else {
494                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
495                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
496                 patch->old_name = patch->new_name = name;
497         }
498         if (!name)
499                 die("unable to find filename in patch at line %d", linenr);
500 }
501
502 static int gitdiff_hdrend(const char *line, struct patch *patch)
503 {
504         return -1;
505 }
506
507 /*
508  * We're anal about diff header consistency, to make
509  * sure that we don't end up having strange ambiguous
510  * patches floating around.
511  *
512  * As a result, gitdiff_{old|new}name() will check
513  * their names against any previous information, just
514  * to make sure..
515  */
516 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
517 {
518         if (!orig_name && !isnull)
519                 return find_name(line, NULL, p_value, TERM_TAB);
520
521         if (orig_name) {
522                 int len;
523                 const char *name;
524                 char *another;
525                 name = orig_name;
526                 len = strlen(name);
527                 if (isnull)
528                         die("git apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
529                 another = find_name(line, NULL, p_value, TERM_TAB);
530                 if (!another || memcmp(another, name, len))
531                         die("git apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
532                 free(another);
533                 return orig_name;
534         }
535         else {
536                 /* expect "/dev/null" */
537                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
538                         die("git apply: bad git-diff - expected /dev/null on line %d", linenr);
539                 return NULL;
540         }
541 }
542
543 static int gitdiff_oldname(const char *line, struct patch *patch)
544 {
545         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
546         return 0;
547 }
548
549 static int gitdiff_newname(const char *line, struct patch *patch)
550 {
551         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
552         return 0;
553 }
554
555 static int gitdiff_oldmode(const char *line, struct patch *patch)
556 {
557         patch->old_mode = strtoul(line, NULL, 8);
558         return 0;
559 }
560
561 static int gitdiff_newmode(const char *line, struct patch *patch)
562 {
563         patch->new_mode = strtoul(line, NULL, 8);
564         return 0;
565 }
566
567 static int gitdiff_delete(const char *line, struct patch *patch)
568 {
569         patch->is_delete = 1;
570         patch->old_name = patch->def_name;
571         return gitdiff_oldmode(line, patch);
572 }
573
574 static int gitdiff_newfile(const char *line, struct patch *patch)
575 {
576         patch->is_new = 1;
577         patch->new_name = patch->def_name;
578         return gitdiff_newmode(line, patch);
579 }
580
581 static int gitdiff_copysrc(const char *line, struct patch *patch)
582 {
583         patch->is_copy = 1;
584         patch->old_name = find_name(line, NULL, 0, 0);
585         return 0;
586 }
587
588 static int gitdiff_copydst(const char *line, struct patch *patch)
589 {
590         patch->is_copy = 1;
591         patch->new_name = find_name(line, NULL, 0, 0);
592         return 0;
593 }
594
595 static int gitdiff_renamesrc(const char *line, struct patch *patch)
596 {
597         patch->is_rename = 1;
598         patch->old_name = find_name(line, NULL, 0, 0);
599         return 0;
600 }
601
602 static int gitdiff_renamedst(const char *line, struct patch *patch)
603 {
604         patch->is_rename = 1;
605         patch->new_name = find_name(line, NULL, 0, 0);
606         return 0;
607 }
608
609 static int gitdiff_similarity(const char *line, struct patch *patch)
610 {
611         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
612                 patch->score = 0;
613         return 0;
614 }
615
616 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
617 {
618         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
619                 patch->score = 0;
620         return 0;
621 }
622
623 static int gitdiff_index(const char *line, struct patch *patch)
624 {
625         /*
626          * index line is N hexadecimal, "..", N hexadecimal,
627          * and optional space with octal mode.
628          */
629         const char *ptr, *eol;
630         int len;
631
632         ptr = strchr(line, '.');
633         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
634                 return 0;
635         len = ptr - line;
636         memcpy(patch->old_sha1_prefix, line, len);
637         patch->old_sha1_prefix[len] = 0;
638
639         line = ptr + 2;
640         ptr = strchr(line, ' ');
641         eol = strchr(line, '\n');
642
643         if (!ptr || eol < ptr)
644                 ptr = eol;
645         len = ptr - line;
646
647         if (40 < len)
648                 return 0;
649         memcpy(patch->new_sha1_prefix, line, len);
650         patch->new_sha1_prefix[len] = 0;
651         if (*ptr == ' ')
652                 patch->old_mode = strtoul(ptr+1, NULL, 8);
653         return 0;
654 }
655
656 /*
657  * This is normal for a diff that doesn't change anything: we'll fall through
658  * into the next diff. Tell the parser to break out.
659  */
660 static int gitdiff_unrecognized(const char *line, struct patch *patch)
661 {
662         return -1;
663 }
664
665 static const char *stop_at_slash(const char *line, int llen)
666 {
667         int i;
668
669         for (i = 0; i < llen; i++) {
670                 int ch = line[i];
671                 if (ch == '/')
672                         return line + i;
673         }
674         return NULL;
675 }
676
677 /*
678  * This is to extract the same name that appears on "diff --git"
679  * line.  We do not find and return anything if it is a rename
680  * patch, and it is OK because we will find the name elsewhere.
681  * We need to reliably find name only when it is mode-change only,
682  * creation or deletion of an empty file.  In any of these cases,
683  * both sides are the same name under a/ and b/ respectively.
684  */
685 static char *git_header_name(char *line, int llen)
686 {
687         const char *name;
688         const char *second = NULL;
689         size_t len;
690
691         line += strlen("diff --git ");
692         llen -= strlen("diff --git ");
693
694         if (*line == '"') {
695                 const char *cp;
696                 struct strbuf first = STRBUF_INIT;
697                 struct strbuf sp = STRBUF_INIT;
698
699                 if (unquote_c_style(&first, line, &second))
700                         goto free_and_fail1;
701
702                 /* advance to the first slash */
703                 cp = stop_at_slash(first.buf, first.len);
704                 /* we do not accept absolute paths */
705                 if (!cp || cp == first.buf)
706                         goto free_and_fail1;
707                 strbuf_remove(&first, 0, cp + 1 - first.buf);
708
709                 /*
710                  * second points at one past closing dq of name.
711                  * find the second name.
712                  */
713                 while ((second < line + llen) && isspace(*second))
714                         second++;
715
716                 if (line + llen <= second)
717                         goto free_and_fail1;
718                 if (*second == '"') {
719                         if (unquote_c_style(&sp, second, NULL))
720                                 goto free_and_fail1;
721                         cp = stop_at_slash(sp.buf, sp.len);
722                         if (!cp || cp == sp.buf)
723                                 goto free_and_fail1;
724                         /* They must match, otherwise ignore */
725                         if (strcmp(cp + 1, first.buf))
726                                 goto free_and_fail1;
727                         strbuf_release(&sp);
728                         return strbuf_detach(&first, NULL);
729                 }
730
731                 /* unquoted second */
732                 cp = stop_at_slash(second, line + llen - second);
733                 if (!cp || cp == second)
734                         goto free_and_fail1;
735                 cp++;
736                 if (line + llen - cp != first.len + 1 ||
737                     memcmp(first.buf, cp, first.len))
738                         goto free_and_fail1;
739                 return strbuf_detach(&first, NULL);
740
741         free_and_fail1:
742                 strbuf_release(&first);
743                 strbuf_release(&sp);
744                 return NULL;
745         }
746
747         /* unquoted first name */
748         name = stop_at_slash(line, llen);
749         if (!name || name == line)
750                 return NULL;
751         name++;
752
753         /*
754          * since the first name is unquoted, a dq if exists must be
755          * the beginning of the second name.
756          */
757         for (second = name; second < line + llen; second++) {
758                 if (*second == '"') {
759                         struct strbuf sp = STRBUF_INIT;
760                         const char *np;
761
762                         if (unquote_c_style(&sp, second, NULL))
763                                 goto free_and_fail2;
764
765                         np = stop_at_slash(sp.buf, sp.len);
766                         if (!np || np == sp.buf)
767                                 goto free_and_fail2;
768                         np++;
769
770                         len = sp.buf + sp.len - np;
771                         if (len < second - name &&
772                             !strncmp(np, name, len) &&
773                             isspace(name[len])) {
774                                 /* Good */
775                                 strbuf_remove(&sp, 0, np - sp.buf);
776                                 return strbuf_detach(&sp, NULL);
777                         }
778
779                 free_and_fail2:
780                         strbuf_release(&sp);
781                         return NULL;
782                 }
783         }
784
785         /*
786          * Accept a name only if it shows up twice, exactly the same
787          * form.
788          */
789         for (len = 0 ; ; len++) {
790                 switch (name[len]) {
791                 default:
792                         continue;
793                 case '\n':
794                         return NULL;
795                 case '\t': case ' ':
796                         second = name+len;
797                         for (;;) {
798                                 char c = *second++;
799                                 if (c == '\n')
800                                         return NULL;
801                                 if (c == '/')
802                                         break;
803                         }
804                         if (second[len] == '\n' && !memcmp(name, second, len)) {
805                                 return xmemdupz(name, len);
806                         }
807                 }
808         }
809 }
810
811 /* Verify that we recognize the lines following a git header */
812 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
813 {
814         unsigned long offset;
815
816         /* A git diff has explicit new/delete information, so we don't guess */
817         patch->is_new = 0;
818         patch->is_delete = 0;
819
820         /*
821          * Some things may not have the old name in the
822          * rest of the headers anywhere (pure mode changes,
823          * or removing or adding empty files), so we get
824          * the default name from the header.
825          */
826         patch->def_name = git_header_name(line, len);
827         if (patch->def_name && root) {
828                 char *s = xmalloc(root_len + strlen(patch->def_name) + 1);
829                 strcpy(s, root);
830                 strcpy(s + root_len, patch->def_name);
831                 free(patch->def_name);
832                 patch->def_name = s;
833         }
834
835         line += len;
836         size -= len;
837         linenr++;
838         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
839                 static const struct opentry {
840                         const char *str;
841                         int (*fn)(const char *, struct patch *);
842                 } optable[] = {
843                         { "@@ -", gitdiff_hdrend },
844                         { "--- ", gitdiff_oldname },
845                         { "+++ ", gitdiff_newname },
846                         { "old mode ", gitdiff_oldmode },
847                         { "new mode ", gitdiff_newmode },
848                         { "deleted file mode ", gitdiff_delete },
849                         { "new file mode ", gitdiff_newfile },
850                         { "copy from ", gitdiff_copysrc },
851                         { "copy to ", gitdiff_copydst },
852                         { "rename old ", gitdiff_renamesrc },
853                         { "rename new ", gitdiff_renamedst },
854                         { "rename from ", gitdiff_renamesrc },
855                         { "rename to ", gitdiff_renamedst },
856                         { "similarity index ", gitdiff_similarity },
857                         { "dissimilarity index ", gitdiff_dissimilarity },
858                         { "index ", gitdiff_index },
859                         { "", gitdiff_unrecognized },
860                 };
861                 int i;
862
863                 len = linelen(line, size);
864                 if (!len || line[len-1] != '\n')
865                         break;
866                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
867                         const struct opentry *p = optable + i;
868                         int oplen = strlen(p->str);
869                         if (len < oplen || memcmp(p->str, line, oplen))
870                                 continue;
871                         if (p->fn(line + oplen, patch) < 0)
872                                 return offset;
873                         break;
874                 }
875         }
876
877         return offset;
878 }
879
880 static int parse_num(const char *line, unsigned long *p)
881 {
882         char *ptr;
883
884         if (!isdigit(*line))
885                 return 0;
886         *p = strtoul(line, &ptr, 10);
887         return ptr - line;
888 }
889
890 static int parse_range(const char *line, int len, int offset, const char *expect,
891                        unsigned long *p1, unsigned long *p2)
892 {
893         int digits, ex;
894
895         if (offset < 0 || offset >= len)
896                 return -1;
897         line += offset;
898         len -= offset;
899
900         digits = parse_num(line, p1);
901         if (!digits)
902                 return -1;
903
904         offset += digits;
905         line += digits;
906         len -= digits;
907
908         *p2 = 1;
909         if (*line == ',') {
910                 digits = parse_num(line+1, p2);
911                 if (!digits)
912                         return -1;
913
914                 offset += digits+1;
915                 line += digits+1;
916                 len -= digits+1;
917         }
918
919         ex = strlen(expect);
920         if (ex > len)
921                 return -1;
922         if (memcmp(line, expect, ex))
923                 return -1;
924
925         return offset + ex;
926 }
927
928 static void recount_diff(char *line, int size, struct fragment *fragment)
929 {
930         int oldlines = 0, newlines = 0, ret = 0;
931
932         if (size < 1) {
933                 warning("recount: ignore empty hunk");
934                 return;
935         }
936
937         for (;;) {
938                 int len = linelen(line, size);
939                 size -= len;
940                 line += len;
941
942                 if (size < 1)
943                         break;
944
945                 switch (*line) {
946                 case ' ': case '\n':
947                         newlines++;
948                         /* fall through */
949                 case '-':
950                         oldlines++;
951                         continue;
952                 case '+':
953                         newlines++;
954                         continue;
955                 case '\\':
956                         continue;
957                 case '@':
958                         ret = size < 3 || prefixcmp(line, "@@ ");
959                         break;
960                 case 'd':
961                         ret = size < 5 || prefixcmp(line, "diff ");
962                         break;
963                 default:
964                         ret = -1;
965                         break;
966                 }
967                 if (ret) {
968                         warning("recount: unexpected line: %.*s",
969                                 (int)linelen(line, size), line);
970                         return;
971                 }
972                 break;
973         }
974         fragment->oldlines = oldlines;
975         fragment->newlines = newlines;
976 }
977
978 /*
979  * Parse a unified diff fragment header of the
980  * form "@@ -a,b +c,d @@"
981  */
982 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
983 {
984         int offset;
985
986         if (!len || line[len-1] != '\n')
987                 return -1;
988
989         /* Figure out the number of lines in a fragment */
990         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
991         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
992
993         return offset;
994 }
995
996 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
997 {
998         unsigned long offset, len;
999
1000         patch->is_toplevel_relative = 0;
1001         patch->is_rename = patch->is_copy = 0;
1002         patch->is_new = patch->is_delete = -1;
1003         patch->old_mode = patch->new_mode = 0;
1004         patch->old_name = patch->new_name = NULL;
1005         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
1006                 unsigned long nextlen;
1007
1008                 len = linelen(line, size);
1009                 if (!len)
1010                         break;
1011
1012                 /* Testing this early allows us to take a few shortcuts.. */
1013                 if (len < 6)
1014                         continue;
1015
1016                 /*
1017                  * Make sure we don't find any unconnected patch fragments.
1018                  * That's a sign that we didn't find a header, and that a
1019                  * patch has become corrupted/broken up.
1020                  */
1021                 if (!memcmp("@@ -", line, 4)) {
1022                         struct fragment dummy;
1023                         if (parse_fragment_header(line, len, &dummy) < 0)
1024                                 continue;
1025                         die("patch fragment without header at line %d: %.*s",
1026                             linenr, (int)len-1, line);
1027                 }
1028
1029                 if (size < len + 6)
1030                         break;
1031
1032                 /*
1033                  * Git patch? It might not have a real patch, just a rename
1034                  * or mode change, so we handle that specially
1035                  */
1036                 if (!memcmp("diff --git ", line, 11)) {
1037                         int git_hdr_len = parse_git_header(line, len, size, patch);
1038                         if (git_hdr_len <= len)
1039                                 continue;
1040                         if (!patch->old_name && !patch->new_name) {
1041                                 if (!patch->def_name)
1042                                         die("git diff header lacks filename information (line %d)", linenr);
1043                                 patch->old_name = patch->new_name = patch->def_name;
1044                         }
1045                         patch->is_toplevel_relative = 1;
1046                         *hdrsize = git_hdr_len;
1047                         return offset;
1048                 }
1049
1050                 /* --- followed by +++ ? */
1051                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
1052                         continue;
1053
1054                 /*
1055                  * We only accept unified patches, so we want it to
1056                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
1057                  * minimum ("@@ -0,0 +1 @@\n" is the shortest).
1058                  */
1059                 nextlen = linelen(line + len, size - len);
1060                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
1061                         continue;
1062
1063                 /* Ok, we'll consider it a patch */
1064                 parse_traditional_patch(line, line+len, patch);
1065                 *hdrsize = len + nextlen;
1066                 linenr += 2;
1067                 return offset;
1068         }
1069         return -1;
1070 }
1071
1072 static void check_whitespace(const char *line, int len, unsigned ws_rule)
1073 {
1074         char *err;
1075         unsigned result = ws_check(line + 1, len - 1, ws_rule);
1076         if (!result)
1077                 return;
1078
1079         whitespace_error++;
1080         if (squelch_whitespace_errors &&
1081             squelch_whitespace_errors < whitespace_error)
1082                 ;
1083         else {
1084                 err = whitespace_error_string(result);
1085                 fprintf(stderr, "%s:%d: %s.\n%.*s\n",
1086                         patch_input_file, linenr, err, len - 2, line + 1);
1087                 free(err);
1088         }
1089 }
1090
1091 /*
1092  * Parse a unified diff. Note that this really needs to parse each
1093  * fragment separately, since the only way to know the difference
1094  * between a "---" that is part of a patch, and a "---" that starts
1095  * the next patch is to look at the line counts..
1096  */
1097 static int parse_fragment(char *line, unsigned long size,
1098                           struct patch *patch, struct fragment *fragment)
1099 {
1100         int added, deleted;
1101         int len = linelen(line, size), offset;
1102         unsigned long oldlines, newlines;
1103         unsigned long leading, trailing;
1104
1105         offset = parse_fragment_header(line, len, fragment);
1106         if (offset < 0)
1107                 return -1;
1108         if (offset > 0 && patch->recount)
1109                 recount_diff(line + offset, size - offset, fragment);
1110         oldlines = fragment->oldlines;
1111         newlines = fragment->newlines;
1112         leading = 0;
1113         trailing = 0;
1114
1115         /* Parse the thing.. */
1116         line += len;
1117         size -= len;
1118         linenr++;
1119         added = deleted = 0;
1120         for (offset = len;
1121              0 < size;
1122              offset += len, size -= len, line += len, linenr++) {
1123                 if (!oldlines && !newlines)
1124                         break;
1125                 len = linelen(line, size);
1126                 if (!len || line[len-1] != '\n')
1127                         return -1;
1128                 switch (*line) {
1129                 default:
1130                         return -1;
1131                 case '\n': /* newer GNU diff, an empty context line */
1132                 case ' ':
1133                         oldlines--;
1134                         newlines--;
1135                         if (!deleted && !added)
1136                                 leading++;
1137                         trailing++;
1138                         break;
1139                 case '-':
1140                         if (apply_in_reverse &&
1141                             ws_error_action != nowarn_ws_error)
1142                                 check_whitespace(line, len, patch->ws_rule);
1143                         deleted++;
1144                         oldlines--;
1145                         trailing = 0;
1146                         break;
1147                 case '+':
1148                         if (!apply_in_reverse &&
1149                             ws_error_action != nowarn_ws_error)
1150                                 check_whitespace(line, len, patch->ws_rule);
1151                         added++;
1152                         newlines--;
1153                         trailing = 0;
1154                         break;
1155
1156                 /*
1157                  * We allow "\ No newline at end of file". Depending
1158                  * on locale settings when the patch was produced we
1159                  * don't know what this line looks like. The only
1160                  * thing we do know is that it begins with "\ ".
1161                  * Checking for 12 is just for sanity check -- any
1162                  * l10n of "\ No newline..." is at least that long.
1163                  */
1164                 case '\\':
1165                         if (len < 12 || memcmp(line, "\\ ", 2))
1166                                 return -1;
1167                         break;
1168                 }
1169         }
1170         if (oldlines || newlines)
1171                 return -1;
1172         fragment->leading = leading;
1173         fragment->trailing = trailing;
1174
1175         /*
1176          * If a fragment ends with an incomplete line, we failed to include
1177          * it in the above loop because we hit oldlines == newlines == 0
1178          * before seeing it.
1179          */
1180         if (12 < size && !memcmp(line, "\\ ", 2))
1181                 offset += linelen(line, size);
1182
1183         patch->lines_added += added;
1184         patch->lines_deleted += deleted;
1185
1186         if (0 < patch->is_new && oldlines)
1187                 return error("new file depends on old contents");
1188         if (0 < patch->is_delete && newlines)
1189                 return error("deleted file still has contents");
1190         return offset;
1191 }
1192
1193 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
1194 {
1195         unsigned long offset = 0;
1196         unsigned long oldlines = 0, newlines = 0, context = 0;
1197         struct fragment **fragp = &patch->fragments;
1198
1199         while (size > 4 && !memcmp(line, "@@ -", 4)) {
1200                 struct fragment *fragment;
1201                 int len;
1202
1203                 fragment = xcalloc(1, sizeof(*fragment));
1204                 len = parse_fragment(line, size, patch, fragment);
1205                 if (len <= 0)
1206                         die("corrupt patch at line %d", linenr);
1207                 fragment->patch = line;
1208                 fragment->size = len;
1209                 oldlines += fragment->oldlines;
1210                 newlines += fragment->newlines;
1211                 context += fragment->leading + fragment->trailing;
1212
1213                 *fragp = fragment;
1214                 fragp = &fragment->next;
1215
1216                 offset += len;
1217                 line += len;
1218                 size -= len;
1219         }
1220
1221         /*
1222          * If something was removed (i.e. we have old-lines) it cannot
1223          * be creation, and if something was added it cannot be
1224          * deletion.  However, the reverse is not true; --unified=0
1225          * patches that only add are not necessarily creation even
1226          * though they do not have any old lines, and ones that only
1227          * delete are not necessarily deletion.
1228          *
1229          * Unfortunately, a real creation/deletion patch do _not_ have
1230          * any context line by definition, so we cannot safely tell it
1231          * apart with --unified=0 insanity.  At least if the patch has
1232          * more than one hunk it is not creation or deletion.
1233          */
1234         if (patch->is_new < 0 &&
1235             (oldlines || (patch->fragments && patch->fragments->next)))
1236                 patch->is_new = 0;
1237         if (patch->is_delete < 0 &&
1238             (newlines || (patch->fragments && patch->fragments->next)))
1239                 patch->is_delete = 0;
1240
1241         if (0 < patch->is_new && oldlines)
1242                 die("new file %s depends on old contents", patch->new_name);
1243         if (0 < patch->is_delete && newlines)
1244                 die("deleted file %s still has contents", patch->old_name);
1245         if (!patch->is_delete && !newlines && context)
1246                 fprintf(stderr, "** warning: file %s becomes empty but "
1247                         "is not deleted\n", patch->new_name);
1248
1249         return offset;
1250 }
1251
1252 static inline int metadata_changes(struct patch *patch)
1253 {
1254         return  patch->is_rename > 0 ||
1255                 patch->is_copy > 0 ||
1256                 patch->is_new > 0 ||
1257                 patch->is_delete ||
1258                 (patch->old_mode && patch->new_mode &&
1259                  patch->old_mode != patch->new_mode);
1260 }
1261
1262 static char *inflate_it(const void *data, unsigned long size,
1263                         unsigned long inflated_size)
1264 {
1265         z_stream stream;
1266         void *out;
1267         int st;
1268
1269         memset(&stream, 0, sizeof(stream));
1270
1271         stream.next_in = (unsigned char *)data;
1272         stream.avail_in = size;
1273         stream.next_out = out = xmalloc(inflated_size);
1274         stream.avail_out = inflated_size;
1275         git_inflate_init(&stream);
1276         st = git_inflate(&stream, Z_FINISH);
1277         git_inflate_end(&stream);
1278         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1279                 free(out);
1280                 return NULL;
1281         }
1282         return out;
1283 }
1284
1285 static struct fragment *parse_binary_hunk(char **buf_p,
1286                                           unsigned long *sz_p,
1287                                           int *status_p,
1288                                           int *used_p)
1289 {
1290         /*
1291          * Expect a line that begins with binary patch method ("literal"
1292          * or "delta"), followed by the length of data before deflating.
1293          * a sequence of 'length-byte' followed by base-85 encoded data
1294          * should follow, terminated by a newline.
1295          *
1296          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1297          * and we would limit the patch line to 66 characters,
1298          * so one line can fit up to 13 groups that would decode
1299          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1300          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1301          */
1302         int llen, used;
1303         unsigned long size = *sz_p;
1304         char *buffer = *buf_p;
1305         int patch_method;
1306         unsigned long origlen;
1307         char *data = NULL;
1308         int hunk_size = 0;
1309         struct fragment *frag;
1310
1311         llen = linelen(buffer, size);
1312         used = llen;
1313
1314         *status_p = 0;
1315
1316         if (!prefixcmp(buffer, "delta ")) {
1317                 patch_method = BINARY_DELTA_DEFLATED;
1318                 origlen = strtoul(buffer + 6, NULL, 10);
1319         }
1320         else if (!prefixcmp(buffer, "literal ")) {
1321                 patch_method = BINARY_LITERAL_DEFLATED;
1322                 origlen = strtoul(buffer + 8, NULL, 10);
1323         }
1324         else
1325                 return NULL;
1326
1327         linenr++;
1328         buffer += llen;
1329         while (1) {
1330                 int byte_length, max_byte_length, newsize;
1331                 llen = linelen(buffer, size);
1332                 used += llen;
1333                 linenr++;
1334                 if (llen == 1) {
1335                         /* consume the blank line */
1336                         buffer++;
1337                         size--;
1338                         break;
1339                 }
1340                 /*
1341                  * Minimum line is "A00000\n" which is 7-byte long,
1342                  * and the line length must be multiple of 5 plus 2.
1343                  */
1344                 if ((llen < 7) || (llen-2) % 5)
1345                         goto corrupt;
1346                 max_byte_length = (llen - 2) / 5 * 4;
1347                 byte_length = *buffer;
1348                 if ('A' <= byte_length && byte_length <= 'Z')
1349                         byte_length = byte_length - 'A' + 1;
1350                 else if ('a' <= byte_length && byte_length <= 'z')
1351                         byte_length = byte_length - 'a' + 27;
1352                 else
1353                         goto corrupt;
1354                 /* if the input length was not multiple of 4, we would
1355                  * have filler at the end but the filler should never
1356                  * exceed 3 bytes
1357                  */
1358                 if (max_byte_length < byte_length ||
1359                     byte_length <= max_byte_length - 4)
1360                         goto corrupt;
1361                 newsize = hunk_size + byte_length;
1362                 data = xrealloc(data, newsize);
1363                 if (decode_85(data + hunk_size, buffer + 1, byte_length))
1364                         goto corrupt;
1365                 hunk_size = newsize;
1366                 buffer += llen;
1367                 size -= llen;
1368         }
1369
1370         frag = xcalloc(1, sizeof(*frag));
1371         frag->patch = inflate_it(data, hunk_size, origlen);
1372         if (!frag->patch)
1373                 goto corrupt;
1374         free(data);
1375         frag->size = origlen;
1376         *buf_p = buffer;
1377         *sz_p = size;
1378         *used_p = used;
1379         frag->binary_patch_method = patch_method;
1380         return frag;
1381
1382  corrupt:
1383         free(data);
1384         *status_p = -1;
1385         error("corrupt binary patch at line %d: %.*s",
1386               linenr-1, llen-1, buffer);
1387         return NULL;
1388 }
1389
1390 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
1391 {
1392         /*
1393          * We have read "GIT binary patch\n"; what follows is a line
1394          * that says the patch method (currently, either "literal" or
1395          * "delta") and the length of data before deflating; a
1396          * sequence of 'length-byte' followed by base-85 encoded data
1397          * follows.
1398          *
1399          * When a binary patch is reversible, there is another binary
1400          * hunk in the same format, starting with patch method (either
1401          * "literal" or "delta") with the length of data, and a sequence
1402          * of length-byte + base-85 encoded data, terminated with another
1403          * empty line.  This data, when applied to the postimage, produces
1404          * the preimage.
1405          */
1406         struct fragment *forward;
1407         struct fragment *reverse;
1408         int status;
1409         int used, used_1;
1410
1411         forward = parse_binary_hunk(&buffer, &size, &status, &used);
1412         if (!forward && !status)
1413                 /* there has to be one hunk (forward hunk) */
1414                 return error("unrecognized binary patch at line %d", linenr-1);
1415         if (status)
1416                 /* otherwise we already gave an error message */
1417                 return status;
1418
1419         reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
1420         if (reverse)
1421                 used += used_1;
1422         else if (status) {
1423                 /*
1424                  * Not having reverse hunk is not an error, but having
1425                  * a corrupt reverse hunk is.
1426                  */
1427                 free((void*) forward->patch);
1428                 free(forward);
1429                 return status;
1430         }
1431         forward->next = reverse;
1432         patch->fragments = forward;
1433         patch->is_binary = 1;
1434         return used;
1435 }
1436
1437 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
1438 {
1439         int hdrsize, patchsize;
1440         int offset = find_header(buffer, size, &hdrsize, patch);
1441
1442         if (offset < 0)
1443                 return offset;
1444
1445         patch->ws_rule = whitespace_rule(patch->new_name
1446                                          ? patch->new_name
1447                                          : patch->old_name);
1448
1449         patchsize = parse_single_patch(buffer + offset + hdrsize,
1450                                        size - offset - hdrsize, patch);
1451
1452         if (!patchsize) {
1453                 static const char *binhdr[] = {
1454                         "Binary files ",
1455                         "Files ",
1456                         NULL,
1457                 };
1458                 static const char git_binary[] = "GIT binary patch\n";
1459                 int i;
1460                 int hd = hdrsize + offset;
1461                 unsigned long llen = linelen(buffer + hd, size - hd);
1462
1463                 if (llen == sizeof(git_binary) - 1 &&
1464                     !memcmp(git_binary, buffer + hd, llen)) {
1465                         int used;
1466                         linenr++;
1467                         used = parse_binary(buffer + hd + llen,
1468                                             size - hd - llen, patch);
1469                         if (used)
1470                                 patchsize = used + llen;
1471                         else
1472                                 patchsize = 0;
1473                 }
1474                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
1475                         for (i = 0; binhdr[i]; i++) {
1476                                 int len = strlen(binhdr[i]);
1477                                 if (len < size - hd &&
1478                                     !memcmp(binhdr[i], buffer + hd, len)) {
1479                                         linenr++;
1480                                         patch->is_binary = 1;
1481                                         patchsize = llen;
1482                                         break;
1483                                 }
1484                         }
1485                 }
1486
1487                 /* Empty patch cannot be applied if it is a text patch
1488                  * without metadata change.  A binary patch appears
1489                  * empty to us here.
1490                  */
1491                 if ((apply || check) &&
1492                     (!patch->is_binary && !metadata_changes(patch)))
1493                         die("patch with only garbage at line %d", linenr);
1494         }
1495
1496         return offset + hdrsize + patchsize;
1497 }
1498
1499 #define swap(a,b) myswap((a),(b),sizeof(a))
1500
1501 #define myswap(a, b, size) do {         \
1502         unsigned char mytmp[size];      \
1503         memcpy(mytmp, &a, size);                \
1504         memcpy(&a, &b, size);           \
1505         memcpy(&b, mytmp, size);                \
1506 } while (0)
1507
1508 static void reverse_patches(struct patch *p)
1509 {
1510         for (; p; p = p->next) {
1511                 struct fragment *frag = p->fragments;
1512
1513                 swap(p->new_name, p->old_name);
1514                 swap(p->new_mode, p->old_mode);
1515                 swap(p->is_new, p->is_delete);
1516                 swap(p->lines_added, p->lines_deleted);
1517                 swap(p->old_sha1_prefix, p->new_sha1_prefix);
1518
1519                 for (; frag; frag = frag->next) {
1520                         swap(frag->newpos, frag->oldpos);
1521                         swap(frag->newlines, frag->oldlines);
1522                 }
1523         }
1524 }
1525
1526 static const char pluses[] =
1527 "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1528 static const char minuses[]=
1529 "----------------------------------------------------------------------";
1530
1531 static void show_stats(struct patch *patch)
1532 {
1533         struct strbuf qname = STRBUF_INIT;
1534         char *cp = patch->new_name ? patch->new_name : patch->old_name;
1535         int max, add, del;
1536
1537         quote_c_style(cp, &qname, NULL, 0);
1538
1539         /*
1540          * "scale" the filename
1541          */
1542         max = max_len;
1543         if (max > 50)
1544                 max = 50;
1545
1546         if (qname.len > max) {
1547                 cp = strchr(qname.buf + qname.len + 3 - max, '/');
1548                 if (!cp)
1549                         cp = qname.buf + qname.len + 3 - max;
1550                 strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
1551         }
1552
1553         if (patch->is_binary) {
1554                 printf(" %-*s |  Bin\n", max, qname.buf);
1555                 strbuf_release(&qname);
1556                 return;
1557         }
1558
1559         printf(" %-*s |", max, qname.buf);
1560         strbuf_release(&qname);
1561
1562         /*
1563          * scale the add/delete
1564          */
1565         max = max + max_change > 70 ? 70 - max : max_change;
1566         add = patch->lines_added;
1567         del = patch->lines_deleted;
1568
1569         if (max_change > 0) {
1570                 int total = ((add + del) * max + max_change / 2) / max_change;
1571                 add = (add * max + max_change / 2) / max_change;
1572                 del = total - add;
1573         }
1574         printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
1575                 add, pluses, del, minuses);
1576 }
1577
1578 static int read_old_data(struct stat *st, const char *path, struct strbuf *buf)
1579 {
1580         switch (st->st_mode & S_IFMT) {
1581         case S_IFLNK:
1582                 if (strbuf_readlink(buf, path, st->st_size) < 0)
1583                         return error("unable to read symlink %s", path);
1584                 return 0;
1585         case S_IFREG:
1586                 if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
1587                         return error("unable to open or read %s", path);
1588                 convert_to_git(path, buf->buf, buf->len, buf, 0);
1589                 return 0;
1590         default:
1591                 return -1;
1592         }
1593 }
1594
1595 static void update_pre_post_images(struct image *preimage,
1596                                    struct image *postimage,
1597                                    char *buf,
1598                                    size_t len)
1599 {
1600         int i, ctx;
1601         char *new, *old, *fixed;
1602         struct image fixed_preimage;
1603
1604         /*
1605          * Update the preimage with whitespace fixes.  Note that we
1606          * are not losing preimage->buf -- apply_one_fragment() will
1607          * free "oldlines".
1608          */
1609         prepare_image(&fixed_preimage, buf, len, 1);
1610         assert(fixed_preimage.nr == preimage->nr);
1611         for (i = 0; i < preimage->nr; i++)
1612                 fixed_preimage.line[i].flag = preimage->line[i].flag;
1613         free(preimage->line_allocated);
1614         *preimage = fixed_preimage;
1615
1616         /*
1617          * Adjust the common context lines in postimage, in place.
1618          * This is possible because whitespace fixing does not make
1619          * the string grow.
1620          */
1621         new = old = postimage->buf;
1622         fixed = preimage->buf;
1623         for (i = ctx = 0; i < postimage->nr; i++) {
1624                 size_t len = postimage->line[i].len;
1625                 if (!(postimage->line[i].flag & LINE_COMMON)) {
1626                         /* an added line -- no counterparts in preimage */
1627                         memmove(new, old, len);
1628                         old += len;
1629                         new += len;
1630                         continue;
1631                 }
1632
1633                 /* a common context -- skip it in the original postimage */
1634                 old += len;
1635
1636                 /* and find the corresponding one in the fixed preimage */
1637                 while (ctx < preimage->nr &&
1638                        !(preimage->line[ctx].flag & LINE_COMMON)) {
1639                         fixed += preimage->line[ctx].len;
1640                         ctx++;
1641                 }
1642                 if (preimage->nr <= ctx)
1643                         die("oops");
1644
1645                 /* and copy it in, while fixing the line length */
1646                 len = preimage->line[ctx].len;
1647                 memcpy(new, fixed, len);
1648                 new += len;
1649                 fixed += len;
1650                 postimage->line[i].len = len;
1651                 ctx++;
1652         }
1653
1654         /* Fix the length of the whole thing */
1655         postimage->len = new - postimage->buf;
1656 }
1657
1658 static int match_fragment(struct image *img,
1659                           struct image *preimage,
1660                           struct image *postimage,
1661                           unsigned long try,
1662                           int try_lno,
1663                           unsigned ws_rule,
1664                           int match_beginning, int match_end)
1665 {
1666         int i;
1667         char *fixed_buf, *buf, *orig, *target;
1668
1669         if (preimage->nr + try_lno > img->nr)
1670                 return 0;
1671
1672         if (match_beginning && try_lno)
1673                 return 0;
1674
1675         if (match_end && preimage->nr + try_lno != img->nr)
1676                 return 0;
1677
1678         /* Quick hash check */
1679         for (i = 0; i < preimage->nr; i++)
1680                 if (preimage->line[i].hash != img->line[try_lno + i].hash)
1681                         return 0;
1682
1683         /*
1684          * Do we have an exact match?  If we were told to match
1685          * at the end, size must be exactly at try+fragsize,
1686          * otherwise try+fragsize must be still within the preimage,
1687          * and either case, the old piece should match the preimage
1688          * exactly.
1689          */
1690         if ((match_end
1691              ? (try + preimage->len == img->len)
1692              : (try + preimage->len <= img->len)) &&
1693             !memcmp(img->buf + try, preimage->buf, preimage->len))
1694                 return 1;
1695
1696         if (ws_error_action != correct_ws_error)
1697                 return 0;
1698
1699         /*
1700          * The hunk does not apply byte-by-byte, but the hash says
1701          * it might with whitespace fuzz.
1702          */
1703         fixed_buf = xmalloc(preimage->len + 1);
1704         buf = fixed_buf;
1705         orig = preimage->buf;
1706         target = img->buf + try;
1707         for (i = 0; i < preimage->nr; i++) {
1708                 size_t fixlen; /* length after fixing the preimage */
1709                 size_t oldlen = preimage->line[i].len;
1710                 size_t tgtlen = img->line[try_lno + i].len;
1711                 size_t tgtfixlen; /* length after fixing the target line */
1712                 char tgtfixbuf[1024], *tgtfix;
1713                 int match;
1714
1715                 /* Try fixing the line in the preimage */
1716                 fixlen = ws_fix_copy(buf, orig, oldlen, ws_rule, NULL);
1717
1718                 /* Try fixing the line in the target */
1719                 if (sizeof(tgtfixbuf) > tgtlen)
1720                         tgtfix = tgtfixbuf;
1721                 else
1722                         tgtfix = xmalloc(tgtlen);
1723                 tgtfixlen = ws_fix_copy(tgtfix, target, tgtlen, ws_rule, NULL);
1724
1725                 /*
1726                  * If they match, either the preimage was based on
1727                  * a version before our tree fixed whitespace breakage,
1728                  * or we are lacking a whitespace-fix patch the tree
1729                  * the preimage was based on already had (i.e. target
1730                  * has whitespace breakage, the preimage doesn't).
1731                  * In either case, we are fixing the whitespace breakages
1732                  * so we might as well take the fix together with their
1733                  * real change.
1734                  */
1735                 match = (tgtfixlen == fixlen && !memcmp(tgtfix, buf, fixlen));
1736
1737                 if (tgtfix != tgtfixbuf)
1738                         free(tgtfix);
1739                 if (!match)
1740                         goto unmatch_exit;
1741
1742                 orig += oldlen;
1743                 buf += fixlen;
1744                 target += tgtlen;
1745         }
1746
1747         /*
1748          * Yes, the preimage is based on an older version that still
1749          * has whitespace breakages unfixed, and fixing them makes the
1750          * hunk match.  Update the context lines in the postimage.
1751          */
1752         update_pre_post_images(preimage, postimage,
1753                                fixed_buf, buf - fixed_buf);
1754         return 1;
1755
1756  unmatch_exit:
1757         free(fixed_buf);
1758         return 0;
1759 }
1760
1761 static int find_pos(struct image *img,
1762                     struct image *preimage,
1763                     struct image *postimage,
1764                     int line,
1765                     unsigned ws_rule,
1766                     int match_beginning, int match_end)
1767 {
1768         int i;
1769         unsigned long backwards, forwards, try;
1770         int backwards_lno, forwards_lno, try_lno;
1771
1772         if (preimage->nr > img->nr)
1773                 return -1;
1774
1775         /*
1776          * If match_begining or match_end is specified, there is no
1777          * point starting from a wrong line that will never match and
1778          * wander around and wait for a match at the specified end.
1779          */
1780         if (match_beginning)
1781                 line = 0;
1782         else if (match_end)
1783                 line = img->nr - preimage->nr;
1784
1785         if (line > img->nr)
1786                 line = img->nr;
1787
1788         try = 0;
1789         for (i = 0; i < line; i++)
1790                 try += img->line[i].len;
1791
1792         /*
1793          * There's probably some smart way to do this, but I'll leave
1794          * that to the smart and beautiful people. I'm simple and stupid.
1795          */
1796         backwards = try;
1797         backwards_lno = line;
1798         forwards = try;
1799         forwards_lno = line;
1800         try_lno = line;
1801
1802         for (i = 0; ; i++) {
1803                 if (match_fragment(img, preimage, postimage,
1804                                    try, try_lno, ws_rule,
1805                                    match_beginning, match_end))
1806                         return try_lno;
1807
1808         again:
1809                 if (backwards_lno == 0 && forwards_lno == img->nr)
1810                         break;
1811
1812                 if (i & 1) {
1813                         if (backwards_lno == 0) {
1814                                 i++;
1815                                 goto again;
1816                         }
1817                         backwards_lno--;
1818                         backwards -= img->line[backwards_lno].len;
1819                         try = backwards;
1820                         try_lno = backwards_lno;
1821                 } else {
1822                         if (forwards_lno == img->nr) {
1823                                 i++;
1824                                 goto again;
1825                         }
1826                         forwards += img->line[forwards_lno].len;
1827                         forwards_lno++;
1828                         try = forwards;
1829                         try_lno = forwards_lno;
1830                 }
1831
1832         }
1833         return -1;
1834 }
1835
1836 static void remove_first_line(struct image *img)
1837 {
1838         img->buf += img->line[0].len;
1839         img->len -= img->line[0].len;
1840         img->line++;
1841         img->nr--;
1842 }
1843
1844 static void remove_last_line(struct image *img)
1845 {
1846         img->len -= img->line[--img->nr].len;
1847 }
1848
1849 static void update_image(struct image *img,
1850                          int applied_pos,
1851                          struct image *preimage,
1852                          struct image *postimage)
1853 {
1854         /*
1855          * remove the copy of preimage at offset in img
1856          * and replace it with postimage
1857          */
1858         int i, nr;
1859         size_t remove_count, insert_count, applied_at = 0;
1860         char *result;
1861
1862         for (i = 0; i < applied_pos; i++)
1863                 applied_at += img->line[i].len;
1864
1865         remove_count = 0;
1866         for (i = 0; i < preimage->nr; i++)
1867                 remove_count += img->line[applied_pos + i].len;
1868         insert_count = postimage->len;
1869
1870         /* Adjust the contents */
1871         result = xmalloc(img->len + insert_count - remove_count + 1);
1872         memcpy(result, img->buf, applied_at);
1873         memcpy(result + applied_at, postimage->buf, postimage->len);
1874         memcpy(result + applied_at + postimage->len,
1875                img->buf + (applied_at + remove_count),
1876                img->len - (applied_at + remove_count));
1877         free(img->buf);
1878         img->buf = result;
1879         img->len += insert_count - remove_count;
1880         result[img->len] = '\0';
1881
1882         /* Adjust the line table */
1883         nr = img->nr + postimage->nr - preimage->nr;
1884         if (preimage->nr < postimage->nr) {
1885                 /*
1886                  * NOTE: this knows that we never call remove_first_line()
1887                  * on anything other than pre/post image.
1888                  */
1889                 img->line = xrealloc(img->line, nr * sizeof(*img->line));
1890                 img->line_allocated = img->line;
1891         }
1892         if (preimage->nr != postimage->nr)
1893                 memmove(img->line + applied_pos + postimage->nr,
1894                         img->line + applied_pos + preimage->nr,
1895                         (img->nr - (applied_pos + preimage->nr)) *
1896                         sizeof(*img->line));
1897         memcpy(img->line + applied_pos,
1898                postimage->line,
1899                postimage->nr * sizeof(*img->line));
1900         img->nr = nr;
1901 }
1902
1903 static int apply_one_fragment(struct image *img, struct fragment *frag,
1904                               int inaccurate_eof, unsigned ws_rule)
1905 {
1906         int match_beginning, match_end;
1907         const char *patch = frag->patch;
1908         int size = frag->size;
1909         char *old, *new, *oldlines, *newlines;
1910         int new_blank_lines_at_end = 0;
1911         unsigned long leading, trailing;
1912         int pos, applied_pos;
1913         struct image preimage;
1914         struct image postimage;
1915
1916         memset(&preimage, 0, sizeof(preimage));
1917         memset(&postimage, 0, sizeof(postimage));
1918         oldlines = xmalloc(size);
1919         newlines = xmalloc(size);
1920
1921         old = oldlines;
1922         new = newlines;
1923         while (size > 0) {
1924                 char first;
1925                 int len = linelen(patch, size);
1926                 int plen, added;
1927                 int added_blank_line = 0;
1928
1929                 if (!len)
1930                         break;
1931
1932                 /*
1933                  * "plen" is how much of the line we should use for
1934                  * the actual patch data. Normally we just remove the
1935                  * first character on the line, but if the line is
1936                  * followed by "\ No newline", then we also remove the
1937                  * last one (which is the newline, of course).
1938                  */
1939                 plen = len - 1;
1940                 if (len < size && patch[len] == '\\')
1941                         plen--;
1942                 first = *patch;
1943                 if (apply_in_reverse) {
1944                         if (first == '-')
1945                                 first = '+';
1946                         else if (first == '+')
1947                                 first = '-';
1948                 }
1949
1950                 switch (first) {
1951                 case '\n':
1952                         /* Newer GNU diff, empty context line */
1953                         if (plen < 0)
1954                                 /* ... followed by '\No newline'; nothing */
1955                                 break;
1956                         *old++ = '\n';
1957                         *new++ = '\n';
1958                         add_line_info(&preimage, "\n", 1, LINE_COMMON);
1959                         add_line_info(&postimage, "\n", 1, LINE_COMMON);
1960                         break;
1961                 case ' ':
1962                 case '-':
1963                         memcpy(old, patch + 1, plen);
1964                         add_line_info(&preimage, old, plen,
1965                                       (first == ' ' ? LINE_COMMON : 0));
1966                         old += plen;
1967                         if (first == '-')
1968                                 break;
1969                 /* Fall-through for ' ' */
1970                 case '+':
1971                         /* --no-add does not add new lines */
1972                         if (first == '+' && no_add)
1973                                 break;
1974
1975                         if (first != '+' ||
1976                             !whitespace_error ||
1977                             ws_error_action != correct_ws_error) {
1978                                 memcpy(new, patch + 1, plen);
1979                                 added = plen;
1980                         }
1981                         else {
1982                                 added = ws_fix_copy(new, patch + 1, plen, ws_rule, &applied_after_fixing_ws);
1983                         }
1984                         add_line_info(&postimage, new, added,
1985                                       (first == '+' ? 0 : LINE_COMMON));
1986                         new += added;
1987                         if (first == '+' &&
1988                             added == 1 && new[-1] == '\n')
1989                                 added_blank_line = 1;
1990                         break;
1991                 case '@': case '\\':
1992                         /* Ignore it, we already handled it */
1993                         break;
1994                 default:
1995                         if (apply_verbosely)
1996                                 error("invalid start of line: '%c'", first);
1997                         return -1;
1998                 }
1999                 if (added_blank_line)
2000                         new_blank_lines_at_end++;
2001                 else
2002                         new_blank_lines_at_end = 0;
2003                 patch += len;
2004                 size -= len;
2005         }
2006         if (inaccurate_eof &&
2007             old > oldlines && old[-1] == '\n' &&
2008             new > newlines && new[-1] == '\n') {
2009                 old--;
2010                 new--;
2011         }
2012
2013         leading = frag->leading;
2014         trailing = frag->trailing;
2015
2016         /*
2017          * A hunk to change lines at the beginning would begin with
2018          * @@ -1,L +N,M @@
2019          * but we need to be careful.  -U0 that inserts before the second
2020          * line also has this pattern.
2021          *
2022          * And a hunk to add to an empty file would begin with
2023          * @@ -0,0 +N,M @@
2024          *
2025          * In other words, a hunk that is (frag->oldpos <= 1) with or
2026          * without leading context must match at the beginning.
2027          */
2028         match_beginning = (!frag->oldpos ||
2029                            (frag->oldpos == 1 && !unidiff_zero));
2030
2031         /*
2032          * A hunk without trailing lines must match at the end.
2033          * However, we simply cannot tell if a hunk must match end
2034          * from the lack of trailing lines if the patch was generated
2035          * with unidiff without any context.
2036          */
2037         match_end = !unidiff_zero && !trailing;
2038
2039         pos = frag->newpos ? (frag->newpos - 1) : 0;
2040         preimage.buf = oldlines;
2041         preimage.len = old - oldlines;
2042         postimage.buf = newlines;
2043         postimage.len = new - newlines;
2044         preimage.line = preimage.line_allocated;
2045         postimage.line = postimage.line_allocated;
2046
2047         for (;;) {
2048
2049                 applied_pos = find_pos(img, &preimage, &postimage, pos,
2050                                        ws_rule, match_beginning, match_end);
2051
2052                 if (applied_pos >= 0)
2053                         break;
2054
2055                 /* Am I at my context limits? */
2056                 if ((leading <= p_context) && (trailing <= p_context))
2057                         break;
2058                 if (match_beginning || match_end) {
2059                         match_beginning = match_end = 0;
2060                         continue;
2061                 }
2062
2063                 /*
2064                  * Reduce the number of context lines; reduce both
2065                  * leading and trailing if they are equal otherwise
2066                  * just reduce the larger context.
2067                  */
2068                 if (leading >= trailing) {
2069                         remove_first_line(&preimage);
2070                         remove_first_line(&postimage);
2071                         pos--;
2072                         leading--;
2073                 }
2074                 if (trailing > leading) {
2075                         remove_last_line(&preimage);
2076                         remove_last_line(&postimage);
2077                         trailing--;
2078                 }
2079         }
2080
2081         if (applied_pos >= 0) {
2082                 if (ws_error_action == correct_ws_error &&
2083                     new_blank_lines_at_end &&
2084                     postimage.nr + applied_pos == img->nr) {
2085                         /*
2086                          * If the patch application adds blank lines
2087                          * at the end, and if the patch applies at the
2088                          * end of the image, remove those added blank
2089                          * lines.
2090                          */
2091                         while (new_blank_lines_at_end--)
2092                                 remove_last_line(&postimage);
2093                 }
2094
2095                 /*
2096                  * Warn if it was necessary to reduce the number
2097                  * of context lines.
2098                  */
2099                 if ((leading != frag->leading) ||
2100                     (trailing != frag->trailing))
2101                         fprintf(stderr, "Context reduced to (%ld/%ld)"
2102                                 " to apply fragment at %d\n",
2103                                 leading, trailing, applied_pos+1);
2104                 update_image(img, applied_pos, &preimage, &postimage);
2105         } else {
2106                 if (apply_verbosely)
2107                         error("while searching for:\n%.*s",
2108                               (int)(old - oldlines), oldlines);
2109         }
2110
2111         free(oldlines);
2112         free(newlines);
2113         free(preimage.line_allocated);
2114         free(postimage.line_allocated);
2115
2116         return (applied_pos < 0);
2117 }
2118
2119 static int apply_binary_fragment(struct image *img, struct patch *patch)
2120 {
2121         struct fragment *fragment = patch->fragments;
2122         unsigned long len;
2123         void *dst;
2124
2125         /* Binary patch is irreversible without the optional second hunk */
2126         if (apply_in_reverse) {
2127                 if (!fragment->next)
2128                         return error("cannot reverse-apply a binary patch "
2129                                      "without the reverse hunk to '%s'",
2130                                      patch->new_name
2131                                      ? patch->new_name : patch->old_name);
2132                 fragment = fragment->next;
2133         }
2134         switch (fragment->binary_patch_method) {
2135         case BINARY_DELTA_DEFLATED:
2136                 dst = patch_delta(img->buf, img->len, fragment->patch,
2137                                   fragment->size, &len);
2138                 if (!dst)
2139                         return -1;
2140                 clear_image(img);
2141                 img->buf = dst;
2142                 img->len = len;
2143                 return 0;
2144         case BINARY_LITERAL_DEFLATED:
2145                 clear_image(img);
2146                 img->len = fragment->size;
2147                 img->buf = xmalloc(img->len+1);
2148                 memcpy(img->buf, fragment->patch, img->len);
2149                 img->buf[img->len] = '\0';
2150                 return 0;
2151         }
2152         return -1;
2153 }
2154
2155 static int apply_binary(struct image *img, struct patch *patch)
2156 {
2157         const char *name = patch->old_name ? patch->old_name : patch->new_name;
2158         unsigned char sha1[20];
2159
2160         /*
2161          * For safety, we require patch index line to contain
2162          * full 40-byte textual SHA1 for old and new, at least for now.
2163          */
2164         if (strlen(patch->old_sha1_prefix) != 40 ||
2165             strlen(patch->new_sha1_prefix) != 40 ||
2166             get_sha1_hex(patch->old_sha1_prefix, sha1) ||
2167             get_sha1_hex(patch->new_sha1_prefix, sha1))
2168                 return error("cannot apply binary patch to '%s' "
2169                              "without full index line", name);
2170
2171         if (patch->old_name) {
2172                 /*
2173                  * See if the old one matches what the patch
2174                  * applies to.
2175                  */
2176                 hash_sha1_file(img->buf, img->len, blob_type, sha1);
2177                 if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
2178                         return error("the patch applies to '%s' (%s), "
2179                                      "which does not match the "
2180                                      "current contents.",
2181                                      name, sha1_to_hex(sha1));
2182         }
2183         else {
2184                 /* Otherwise, the old one must be empty. */
2185                 if (img->len)
2186                         return error("the patch applies to an empty "
2187                                      "'%s' but it is not empty", name);
2188         }
2189
2190         get_sha1_hex(patch->new_sha1_prefix, sha1);
2191         if (is_null_sha1(sha1)) {
2192                 clear_image(img);
2193                 return 0; /* deletion patch */
2194         }
2195
2196         if (has_sha1_file(sha1)) {
2197                 /* We already have the postimage */
2198                 enum object_type type;
2199                 unsigned long size;
2200                 char *result;
2201
2202                 result = read_sha1_file(sha1, &type, &size);
2203                 if (!result)
2204                         return error("the necessary postimage %s for "
2205                                      "'%s' cannot be read",
2206                                      patch->new_sha1_prefix, name);
2207                 clear_image(img);
2208                 img->buf = result;
2209                 img->len = size;
2210         } else {
2211                 /*
2212                  * We have verified buf matches the preimage;
2213                  * apply the patch data to it, which is stored
2214                  * in the patch->fragments->{patch,size}.
2215                  */
2216                 if (apply_binary_fragment(img, patch))
2217                         return error("binary patch does not apply to '%s'",
2218                                      name);
2219
2220                 /* verify that the result matches */
2221                 hash_sha1_file(img->buf, img->len, blob_type, sha1);
2222                 if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
2223                         return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)",
2224                                 name, patch->new_sha1_prefix, sha1_to_hex(sha1));
2225         }
2226
2227         return 0;
2228 }
2229
2230 static int apply_fragments(struct image *img, struct patch *patch)
2231 {
2232         struct fragment *frag = patch->fragments;
2233         const char *name = patch->old_name ? patch->old_name : patch->new_name;
2234         unsigned ws_rule = patch->ws_rule;
2235         unsigned inaccurate_eof = patch->inaccurate_eof;
2236
2237         if (patch->is_binary)
2238                 return apply_binary(img, patch);
2239
2240         while (frag) {
2241                 if (apply_one_fragment(img, frag, inaccurate_eof, ws_rule)) {
2242                         error("patch failed: %s:%ld", name, frag->oldpos);
2243                         if (!apply_with_reject)
2244                                 return -1;
2245                         frag->rejected = 1;
2246                 }
2247                 frag = frag->next;
2248         }
2249         return 0;
2250 }
2251
2252 static int read_file_or_gitlink(struct cache_entry *ce, struct strbuf *buf)
2253 {
2254         if (!ce)
2255                 return 0;
2256
2257         if (S_ISGITLINK(ce->ce_mode)) {
2258                 strbuf_grow(buf, 100);
2259                 strbuf_addf(buf, "Subproject commit %s\n", sha1_to_hex(ce->sha1));
2260         } else {
2261                 enum object_type type;
2262                 unsigned long sz;
2263                 char *result;
2264
2265                 result = read_sha1_file(ce->sha1, &type, &sz);
2266                 if (!result)
2267                         return -1;
2268                 /* XXX read_sha1_file NUL-terminates */
2269                 strbuf_attach(buf, result, sz, sz + 1);
2270         }
2271         return 0;
2272 }
2273
2274 static struct patch *in_fn_table(const char *name)
2275 {
2276         struct string_list_item *item;
2277
2278         if (name == NULL)
2279                 return NULL;
2280
2281         item = string_list_lookup(name, &fn_table);
2282         if (item != NULL)
2283                 return (struct patch *)item->util;
2284
2285         return NULL;
2286 }
2287
2288 /*
2289  * item->util in the filename table records the status of the path.
2290  * Usually it points at a patch (whose result records the contents
2291  * of it after applying it), but it could be PATH_WAS_DELETED for a
2292  * path that a previously applied patch has already removed.
2293  */
2294  #define PATH_TO_BE_DELETED ((struct patch *) -2)
2295 #define PATH_WAS_DELETED ((struct patch *) -1)
2296
2297 static int to_be_deleted(struct patch *patch)
2298 {
2299         return patch == PATH_TO_BE_DELETED;
2300 }
2301
2302 static int was_deleted(struct patch *patch)
2303 {
2304         return patch == PATH_WAS_DELETED;
2305 }
2306
2307 static void add_to_fn_table(struct patch *patch)
2308 {
2309         struct string_list_item *item;
2310
2311         /*
2312          * Always add new_name unless patch is a deletion
2313          * This should cover the cases for normal diffs,
2314          * file creations and copies
2315          */
2316         if (patch->new_name != NULL) {
2317                 item = string_list_insert(patch->new_name, &fn_table);
2318                 item->util = patch;
2319         }
2320
2321         /*
2322          * store a failure on rename/deletion cases because
2323          * later chunks shouldn't patch old names
2324          */
2325         if ((patch->new_name == NULL) || (patch->is_rename)) {
2326                 item = string_list_insert(patch->old_name, &fn_table);
2327                 item->util = PATH_WAS_DELETED;
2328         }
2329 }
2330
2331 static void prepare_fn_table(struct patch *patch)
2332 {
2333         /*
2334          * store information about incoming file deletion
2335          */
2336         while (patch) {
2337                 if ((patch->new_name == NULL) || (patch->is_rename)) {
2338                         struct string_list_item *item;
2339                         item = string_list_insert(patch->old_name, &fn_table);
2340                         item->util = PATH_TO_BE_DELETED;
2341                 }
2342                 patch = patch->next;
2343         }
2344 }
2345
2346 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
2347 {
2348         struct strbuf buf = STRBUF_INIT;
2349         struct image image;
2350         size_t len;
2351         char *img;
2352         struct patch *tpatch;
2353
2354         if (!(patch->is_copy || patch->is_rename) &&
2355             (tpatch = in_fn_table(patch->old_name)) != NULL && !to_be_deleted(tpatch)) {
2356                 if (was_deleted(tpatch)) {
2357                         return error("patch %s has been renamed/deleted",
2358                                 patch->old_name);
2359                 }
2360                 /* We have a patched copy in memory use that */
2361                 strbuf_add(&buf, tpatch->result, tpatch->resultsize);
2362         } else if (cached) {
2363                 if (read_file_or_gitlink(ce, &buf))
2364                         return error("read of %s failed", patch->old_name);
2365         } else if (patch->old_name) {
2366                 if (S_ISGITLINK(patch->old_mode)) {
2367                         if (ce) {
2368                                 read_file_or_gitlink(ce, &buf);
2369                         } else {
2370                                 /*
2371                                  * There is no way to apply subproject
2372                                  * patch without looking at the index.
2373                                  */
2374                                 patch->fragments = NULL;
2375                         }
2376                 } else {
2377                         if (read_old_data(st, patch->old_name, &buf))
2378                                 return error("read of %s failed", patch->old_name);
2379                 }
2380         }
2381
2382         img = strbuf_detach(&buf, &len);
2383         prepare_image(&image, img, len, !patch->is_binary);
2384
2385         if (apply_fragments(&image, patch) < 0)
2386                 return -1; /* note with --reject this succeeds. */
2387         patch->result = image.buf;
2388         patch->resultsize = image.len;
2389         add_to_fn_table(patch);
2390         free(image.line_allocated);
2391
2392         if (0 < patch->is_delete && patch->resultsize)
2393                 return error("removal patch leaves file contents");
2394
2395         return 0;
2396 }
2397
2398 static int check_to_create_blob(const char *new_name, int ok_if_exists)
2399 {
2400         struct stat nst;
2401         if (!lstat(new_name, &nst)) {
2402                 if (S_ISDIR(nst.st_mode) || ok_if_exists)
2403                         return 0;
2404                 /*
2405                  * A leading component of new_name might be a symlink
2406                  * that is going to be removed with this patch, but
2407                  * still pointing at somewhere that has the path.
2408                  * In such a case, path "new_name" does not exist as
2409                  * far as git is concerned.
2410                  */
2411                 if (has_symlink_leading_path(new_name, strlen(new_name)))
2412                         return 0;
2413
2414                 return error("%s: already exists in working directory", new_name);
2415         }
2416         else if ((errno != ENOENT) && (errno != ENOTDIR))
2417                 return error("%s: %s", new_name, strerror(errno));
2418         return 0;
2419 }
2420
2421 static int verify_index_match(struct cache_entry *ce, struct stat *st)
2422 {
2423         if (S_ISGITLINK(ce->ce_mode)) {
2424                 if (!S_ISDIR(st->st_mode))
2425                         return -1;
2426                 return 0;
2427         }
2428         return ce_match_stat(ce, st, CE_MATCH_IGNORE_VALID);
2429 }
2430
2431 static int check_preimage(struct patch *patch, struct cache_entry **ce, struct stat *st)
2432 {
2433         const char *old_name = patch->old_name;
2434         struct patch *tpatch = NULL;
2435         int stat_ret = 0;
2436         unsigned st_mode = 0;
2437
2438         /*
2439          * Make sure that we do not have local modifications from the
2440          * index when we are looking at the index.  Also make sure
2441          * we have the preimage file to be patched in the work tree,
2442          * unless --cached, which tells git to apply only in the index.
2443          */
2444         if (!old_name)
2445                 return 0;
2446
2447         assert(patch->is_new <= 0);
2448
2449         if (!(patch->is_copy || patch->is_rename) &&
2450             (tpatch = in_fn_table(old_name)) != NULL && !to_be_deleted(tpatch)) {
2451                 if (was_deleted(tpatch))
2452                         return error("%s: has been deleted/renamed", old_name);
2453                 st_mode = tpatch->new_mode;
2454         } else if (!cached) {
2455                 stat_ret = lstat(old_name, st);
2456                 if (stat_ret && errno != ENOENT)
2457                         return error("%s: %s", old_name, strerror(errno));
2458         }
2459
2460         if (to_be_deleted(tpatch))
2461                 tpatch = NULL;
2462
2463         if (check_index && !tpatch) {
2464                 int pos = cache_name_pos(old_name, strlen(old_name));
2465                 if (pos < 0) {
2466                         if (patch->is_new < 0)
2467                                 goto is_new;
2468                         return error("%s: does not exist in index", old_name);
2469                 }
2470                 *ce = active_cache[pos];
2471                 if (stat_ret < 0) {
2472                         struct checkout costate;
2473                         /* checkout */
2474                         costate.base_dir = "";
2475                         costate.base_dir_len = 0;
2476                         costate.force = 0;
2477                         costate.quiet = 0;
2478                         costate.not_new = 0;
2479                         costate.refresh_cache = 1;
2480                         if (checkout_entry(*ce, &costate, NULL) ||
2481                             lstat(old_name, st))
2482                                 return -1;
2483                 }
2484                 if (!cached && verify_index_match(*ce, st))
2485                         return error("%s: does not match index", old_name);
2486                 if (cached)
2487                         st_mode = (*ce)->ce_mode;
2488         } else if (stat_ret < 0) {
2489                 if (patch->is_new < 0)
2490                         goto is_new;
2491                 return error("%s: %s", old_name, strerror(errno));
2492         }
2493
2494         if (!cached && !tpatch)
2495                 st_mode = ce_mode_from_stat(*ce, st->st_mode);
2496
2497         if (patch->is_new < 0)
2498                 patch->is_new = 0;
2499         if (!patch->old_mode)
2500                 patch->old_mode = st_mode;
2501         if ((st_mode ^ patch->old_mode) & S_IFMT)
2502                 return error("%s: wrong type", old_name);
2503         if (st_mode != patch->old_mode)
2504                 warning("%s has type %o, expected %o",
2505                         old_name, st_mode, patch->old_mode);
2506         if (!patch->new_mode && !patch->is_delete)
2507                 patch->new_mode = st_mode;
2508         return 0;
2509
2510  is_new:
2511         patch->is_new = 1;
2512         patch->is_delete = 0;
2513         patch->old_name = NULL;
2514         return 0;
2515 }
2516
2517 static int check_patch(struct patch *patch)
2518 {
2519         struct stat st;
2520         const char *old_name = patch->old_name;
2521         const char *new_name = patch->new_name;
2522         const char *name = old_name ? old_name : new_name;
2523         struct cache_entry *ce = NULL;
2524         struct patch *tpatch;
2525         int ok_if_exists;
2526         int status;
2527
2528         patch->rejected = 1; /* we will drop this after we succeed */
2529
2530         status = check_preimage(patch, &ce, &st);
2531         if (status)
2532                 return status;
2533         old_name = patch->old_name;
2534
2535         if ((tpatch = in_fn_table(new_name)) &&
2536                         (was_deleted(tpatch) || to_be_deleted(tpatch)))
2537                 /*
2538                  * A type-change diff is always split into a patch to
2539                  * delete old, immediately followed by a patch to
2540                  * create new (see diff.c::run_diff()); in such a case
2541                  * it is Ok that the entry to be deleted by the
2542                  * previous patch is still in the working tree and in
2543                  * the index.
2544                  */
2545                 ok_if_exists = 1;
2546         else
2547                 ok_if_exists = 0;
2548
2549         if (new_name &&
2550             ((0 < patch->is_new) | (0 < patch->is_rename) | patch->is_copy)) {
2551                 if (check_index &&
2552                     cache_name_pos(new_name, strlen(new_name)) >= 0 &&
2553                     !ok_if_exists)
2554                         return error("%s: already exists in index", new_name);
2555                 if (!cached) {
2556                         int err = check_to_create_blob(new_name, ok_if_exists);
2557                         if (err)
2558                                 return err;
2559                 }
2560                 if (!patch->new_mode) {
2561                         if (0 < patch->is_new)
2562                                 patch->new_mode = S_IFREG | 0644;
2563                         else
2564                                 patch->new_mode = patch->old_mode;
2565                 }
2566         }
2567
2568         if (new_name && old_name) {
2569                 int same = !strcmp(old_name, new_name);
2570                 if (!patch->new_mode)
2571                         patch->new_mode = patch->old_mode;
2572                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
2573                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
2574                                 patch->new_mode, new_name, patch->old_mode,
2575                                 same ? "" : " of ", same ? "" : old_name);
2576         }
2577
2578         if (apply_data(patch, &st, ce) < 0)
2579                 return error("%s: patch does not apply", name);
2580         patch->rejected = 0;
2581         return 0;
2582 }
2583
2584 static int check_patch_list(struct patch *patch)
2585 {
2586         int err = 0;
2587
2588         prepare_fn_table(patch);
2589         while (patch) {
2590                 if (apply_verbosely)
2591                         say_patch_name(stderr,
2592                                        "Checking patch ", patch, "...\n");
2593                 err |= check_patch(patch);
2594                 patch = patch->next;
2595         }
2596         return err;
2597 }
2598
2599 /* This function tries to read the sha1 from the current index */
2600 static int get_current_sha1(const char *path, unsigned char *sha1)
2601 {
2602         int pos;
2603
2604         if (read_cache() < 0)
2605                 return -1;
2606         pos = cache_name_pos(path, strlen(path));
2607         if (pos < 0)
2608                 return -1;
2609         hashcpy(sha1, active_cache[pos]->sha1);
2610         return 0;
2611 }
2612
2613 /* Build an index that contains the just the files needed for a 3way merge */
2614 static void build_fake_ancestor(struct patch *list, const char *filename)
2615 {
2616         struct patch *patch;
2617         struct index_state result = { NULL };
2618         int fd;
2619
2620         /* Once we start supporting the reverse patch, it may be
2621          * worth showing the new sha1 prefix, but until then...
2622          */
2623         for (patch = list; patch; patch = patch->next) {
2624                 const unsigned char *sha1_ptr;
2625                 unsigned char sha1[20];
2626                 struct cache_entry *ce;
2627                 const char *name;
2628
2629                 name = patch->old_name ? patch->old_name : patch->new_name;
2630                 if (0 < patch->is_new)
2631                         continue;
2632                 else if (get_sha1(patch->old_sha1_prefix, sha1))
2633                         /* git diff has no index line for mode/type changes */
2634                         if (!patch->lines_added && !patch->lines_deleted) {
2635                                 if (get_current_sha1(patch->new_name, sha1) ||
2636                                     get_current_sha1(patch->old_name, sha1))
2637                                         die("mode change for %s, which is not "
2638                                                 "in current HEAD", name);
2639                                 sha1_ptr = sha1;
2640                         } else
2641                                 die("sha1 information is lacking or useless "
2642                                         "(%s).", name);
2643                 else
2644                         sha1_ptr = sha1;
2645
2646                 ce = make_cache_entry(patch->old_mode, sha1_ptr, name, 0, 0);
2647                 if (!ce)
2648                         die("make_cache_entry failed for path '%s'", name);
2649                 if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))
2650                         die ("Could not add %s to temporary index", name);
2651         }
2652
2653         fd = open(filename, O_WRONLY | O_CREAT, 0666);
2654         if (fd < 0 || write_index(&result, fd) || close(fd))
2655                 die ("Could not write temporary index to %s", filename);
2656
2657         discard_index(&result);
2658 }
2659
2660 static void stat_patch_list(struct patch *patch)
2661 {
2662         int files, adds, dels;
2663
2664         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
2665                 files++;
2666                 adds += patch->lines_added;
2667                 dels += patch->lines_deleted;
2668                 show_stats(patch);
2669         }
2670
2671         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
2672 }
2673
2674 static void numstat_patch_list(struct patch *patch)
2675 {
2676         for ( ; patch; patch = patch->next) {
2677                 const char *name;
2678                 name = patch->new_name ? patch->new_name : patch->old_name;
2679                 if (patch->is_binary)
2680                         printf("-\t-\t");
2681                 else
2682                         printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
2683                 write_name_quoted(name, stdout, line_termination);
2684         }
2685 }
2686
2687 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
2688 {
2689         if (mode)
2690                 printf(" %s mode %06o %s\n", newdelete, mode, name);
2691         else
2692                 printf(" %s %s\n", newdelete, name);
2693 }
2694
2695 static void show_mode_change(struct patch *p, int show_name)
2696 {
2697         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
2698                 if (show_name)
2699                         printf(" mode change %06o => %06o %s\n",
2700                                p->old_mode, p->new_mode, p->new_name);
2701                 else
2702                         printf(" mode change %06o => %06o\n",
2703                                p->old_mode, p->new_mode);
2704         }
2705 }
2706
2707 static void show_rename_copy(struct patch *p)
2708 {
2709         const char *renamecopy = p->is_rename ? "rename" : "copy";
2710         const char *old, *new;
2711
2712         /* Find common prefix */
2713         old = p->old_name;
2714         new = p->new_name;
2715         while (1) {
2716                 const char *slash_old, *slash_new;
2717                 slash_old = strchr(old, '/');
2718                 slash_new = strchr(new, '/');
2719                 if (!slash_old ||
2720                     !slash_new ||
2721                     slash_old - old != slash_new - new ||
2722                     memcmp(old, new, slash_new - new))
2723                         break;
2724                 old = slash_old + 1;
2725                 new = slash_new + 1;
2726         }
2727         /* p->old_name thru old is the common prefix, and old and new
2728          * through the end of names are renames
2729          */
2730         if (old != p->old_name)
2731                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2732                        (int)(old - p->old_name), p->old_name,
2733                        old, new, p->score);
2734         else
2735                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2736                        p->old_name, p->new_name, p->score);
2737         show_mode_change(p, 0);
2738 }
2739
2740 static void summary_patch_list(struct patch *patch)
2741 {
2742         struct patch *p;
2743
2744         for (p = patch; p; p = p->next) {
2745                 if (p->is_new)
2746                         show_file_mode_name("create", p->new_mode, p->new_name);
2747                 else if (p->is_delete)
2748                         show_file_mode_name("delete", p->old_mode, p->old_name);
2749                 else {
2750                         if (p->is_rename || p->is_copy)
2751                                 show_rename_copy(p);
2752                         else {
2753                                 if (p->score) {
2754                                         printf(" rewrite %s (%d%%)\n",
2755                                                p->new_name, p->score);
2756                                         show_mode_change(p, 0);
2757                                 }
2758                                 else
2759                                         show_mode_change(p, 1);
2760                         }
2761                 }
2762         }
2763 }
2764
2765 static void patch_stats(struct patch *patch)
2766 {
2767         int lines = patch->lines_added + patch->lines_deleted;
2768
2769         if (lines > max_change)
2770                 max_change = lines;
2771         if (patch->old_name) {
2772                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
2773                 if (!len)
2774                         len = strlen(patch->old_name);
2775                 if (len > max_len)
2776                         max_len = len;
2777         }
2778         if (patch->new_name) {
2779                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
2780                 if (!len)
2781                         len = strlen(patch->new_name);
2782                 if (len > max_len)
2783                         max_len = len;
2784         }
2785 }
2786
2787 static void remove_file(struct patch *patch, int rmdir_empty)
2788 {
2789         if (update_index) {
2790                 if (remove_file_from_cache(patch->old_name) < 0)
2791                         die("unable to remove %s from index", patch->old_name);
2792         }
2793         if (!cached) {
2794                 if (S_ISGITLINK(patch->old_mode)) {
2795                         if (rmdir(patch->old_name))
2796                                 warning("unable to remove submodule %s",
2797                                         patch->old_name);
2798                 } else if (!unlink_or_warn(patch->old_name) && rmdir_empty) {
2799                         remove_path(patch->old_name);
2800                 }
2801         }
2802 }
2803
2804 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
2805 {
2806         struct stat st;
2807         struct cache_entry *ce;
2808         int namelen = strlen(path);
2809         unsigned ce_size = cache_entry_size(namelen);
2810
2811         if (!update_index)
2812                 return;
2813
2814         ce = xcalloc(1, ce_size);
2815         memcpy(ce->name, path, namelen);
2816         ce->ce_mode = create_ce_mode(mode);
2817         ce->ce_flags = namelen;
2818         if (S_ISGITLINK(mode)) {
2819                 const char *s = buf;
2820
2821                 if (get_sha1_hex(s + strlen("Subproject commit "), ce->sha1))
2822                         die("corrupt patch for subproject %s", path);
2823         } else {
2824                 if (!cached) {
2825                         if (lstat(path, &st) < 0)
2826                                 die_errno("unable to stat newly created file '%s'",
2827                                           path);
2828                         fill_stat_cache_info(ce, &st);
2829                 }
2830                 if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
2831                         die("unable to create backing store for newly created file %s", path);
2832         }
2833         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
2834                 die("unable to add cache entry for %s", path);
2835 }
2836
2837 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
2838 {
2839         int fd;
2840         struct strbuf nbuf = STRBUF_INIT;
2841
2842         if (S_ISGITLINK(mode)) {
2843                 struct stat st;
2844                 if (!lstat(path, &st) && S_ISDIR(st.st_mode))
2845                         return 0;
2846                 return mkdir(path, 0777);
2847         }
2848
2849         if (has_symlinks && S_ISLNK(mode))
2850                 /* Although buf:size is counted string, it also is NUL
2851                  * terminated.
2852                  */
2853                 return symlink(buf, path);
2854
2855         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
2856         if (fd < 0)
2857                 return -1;
2858
2859         if (convert_to_working_tree(path, buf, size, &nbuf)) {
2860                 size = nbuf.len;
2861                 buf  = nbuf.buf;
2862         }
2863         write_or_die(fd, buf, size);
2864         strbuf_release(&nbuf);
2865
2866         if (close(fd) < 0)
2867                 die_errno("closing file '%s'", path);
2868         return 0;
2869 }
2870
2871 /*
2872  * We optimistically assume that the directories exist,
2873  * which is true 99% of the time anyway. If they don't,
2874  * we create them and try again.
2875  */
2876 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
2877 {
2878         if (cached)
2879                 return;
2880         if (!try_create_file(path, mode, buf, size))
2881                 return;
2882
2883         if (errno == ENOENT) {
2884                 if (safe_create_leading_directories(path))
2885                         return;
2886                 if (!try_create_file(path, mode, buf, size))
2887                         return;
2888         }
2889
2890         if (errno == EEXIST || errno == EACCES) {
2891                 /* We may be trying to create a file where a directory
2892                  * used to be.
2893                  */
2894                 struct stat st;
2895                 if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
2896                         errno = EEXIST;
2897         }
2898
2899         if (errno == EEXIST) {
2900                 unsigned int nr = getpid();
2901
2902                 for (;;) {
2903                         char newpath[PATH_MAX];
2904                         mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
2905                         if (!try_create_file(newpath, mode, buf, size)) {
2906                                 if (!rename(newpath, path))
2907                                         return;
2908                                 unlink_or_warn(newpath);
2909                                 break;
2910                         }
2911                         if (errno != EEXIST)
2912                                 break;
2913                         ++nr;
2914                 }
2915         }
2916         die_errno("unable to write file '%s' mode %o", path, mode);
2917 }
2918
2919 static void create_file(struct patch *patch)
2920 {
2921         char *path = patch->new_name;
2922         unsigned mode = patch->new_mode;
2923         unsigned long size = patch->resultsize;
2924         char *buf = patch->result;
2925
2926         if (!mode)
2927                 mode = S_IFREG | 0644;
2928         create_one_file(path, mode, buf, size);
2929         add_index_file(path, mode, buf, size);
2930 }
2931
2932 /* phase zero is to remove, phase one is to create */
2933 static void write_out_one_result(struct patch *patch, int phase)
2934 {
2935         if (patch->is_delete > 0) {
2936                 if (phase == 0)
2937                         remove_file(patch, 1);
2938                 return;
2939         }
2940         if (patch->is_new > 0 || patch->is_copy) {
2941                 if (phase == 1)
2942                         create_file(patch);
2943                 return;
2944         }
2945         /*
2946          * Rename or modification boils down to the same
2947          * thing: remove the old, write the new
2948          */
2949         if (phase == 0)
2950                 remove_file(patch, patch->is_rename);
2951         if (phase == 1)
2952                 create_file(patch);
2953 }
2954
2955 static int write_out_one_reject(struct patch *patch)
2956 {
2957         FILE *rej;
2958         char namebuf[PATH_MAX];
2959         struct fragment *frag;
2960         int cnt = 0;
2961
2962         for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
2963                 if (!frag->rejected)
2964                         continue;
2965                 cnt++;
2966         }
2967
2968         if (!cnt) {
2969                 if (apply_verbosely)
2970                         say_patch_name(stderr,
2971                                        "Applied patch ", patch, " cleanly.\n");
2972                 return 0;
2973         }
2974
2975         /* This should not happen, because a removal patch that leaves
2976          * contents are marked "rejected" at the patch level.
2977          */
2978         if (!patch->new_name)
2979                 die("internal error");
2980
2981         /* Say this even without --verbose */
2982         say_patch_name(stderr, "Applying patch ", patch, " with");
2983         fprintf(stderr, " %d rejects...\n", cnt);
2984
2985         cnt = strlen(patch->new_name);
2986         if (ARRAY_SIZE(namebuf) <= cnt + 5) {
2987                 cnt = ARRAY_SIZE(namebuf) - 5;
2988                 warning("truncating .rej filename to %.*s.rej",
2989                         cnt - 1, patch->new_name);
2990         }
2991         memcpy(namebuf, patch->new_name, cnt);
2992         memcpy(namebuf + cnt, ".rej", 5);
2993
2994         rej = fopen(namebuf, "w");
2995         if (!rej)
2996                 return error("cannot open %s: %s", namebuf, strerror(errno));
2997
2998         /* Normal git tools never deal with .rej, so do not pretend
2999          * this is a git patch by saying --git nor give extended
3000          * headers.  While at it, maybe please "kompare" that wants
3001          * the trailing TAB and some garbage at the end of line ;-).
3002          */
3003         fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
3004                 patch->new_name, patch->new_name);
3005         for (cnt = 1, frag = patch->fragments;
3006              frag;
3007              cnt++, frag = frag->next) {
3008                 if (!frag->rejected) {
3009                         fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
3010                         continue;
3011                 }
3012                 fprintf(stderr, "Rejected hunk #%d.\n", cnt);
3013                 fprintf(rej, "%.*s", frag->size, frag->patch);
3014                 if (frag->patch[frag->size-1] != '\n')
3015                         fputc('\n', rej);
3016         }
3017         fclose(rej);
3018         return -1;
3019 }
3020
3021 static int write_out_results(struct patch *list, int skipped_patch)
3022 {
3023         int phase;
3024         int errs = 0;
3025         struct patch *l;
3026
3027         if (!list && !skipped_patch)
3028                 return error("No changes");
3029
3030         for (phase = 0; phase < 2; phase++) {
3031                 l = list;
3032                 while (l) {
3033                         if (l->rejected)
3034                                 errs = 1;
3035                         else {
3036                                 write_out_one_result(l, phase);
3037                                 if (phase == 1 && write_out_one_reject(l))
3038                                         errs = 1;
3039                         }
3040                         l = l->next;
3041                 }
3042         }
3043         return errs;
3044 }
3045
3046 static struct lock_file lock_file;
3047
3048 static struct string_list limit_by_name;
3049 static int has_include;
3050 static void add_name_limit(const char *name, int exclude)
3051 {
3052         struct string_list_item *it;
3053
3054         it = string_list_append(name, &limit_by_name);
3055         it->util = exclude ? NULL : (void *) 1;
3056 }
3057
3058 static int use_patch(struct patch *p)
3059 {
3060         const char *pathname = p->new_name ? p->new_name : p->old_name;
3061         int i;
3062
3063         /* Paths outside are not touched regardless of "--include" */
3064         if (0 < prefix_length) {
3065                 int pathlen = strlen(pathname);
3066                 if (pathlen <= prefix_length ||
3067                     memcmp(prefix, pathname, prefix_length))
3068                         return 0;
3069         }
3070
3071         /* See if it matches any of exclude/include rule */
3072         for (i = 0; i < limit_by_name.nr; i++) {
3073                 struct string_list_item *it = &limit_by_name.items[i];
3074                 if (!fnmatch(it->string, pathname, 0))
3075                         return (it->util != NULL);
3076         }
3077
3078         /*
3079          * If we had any include, a path that does not match any rule is
3080          * not used.  Otherwise, we saw bunch of exclude rules (or none)
3081          * and such a path is used.
3082          */
3083         return !has_include;
3084 }
3085
3086
3087 static void prefix_one(char **name)
3088 {
3089         char *old_name = *name;
3090         if (!old_name)
3091                 return;
3092         *name = xstrdup(prefix_filename(prefix, prefix_length, *name));
3093         free(old_name);
3094 }
3095
3096 static void prefix_patches(struct patch *p)
3097 {
3098         if (!prefix || p->is_toplevel_relative)
3099                 return;
3100         for ( ; p; p = p->next) {
3101                 if (p->new_name == p->old_name) {
3102                         char *prefixed = p->new_name;
3103                         prefix_one(&prefixed);
3104                         p->new_name = p->old_name = prefixed;
3105                 }
3106                 else {
3107                         prefix_one(&p->new_name);
3108                         prefix_one(&p->old_name);
3109                 }
3110         }
3111 }
3112
3113 #define INACCURATE_EOF  (1<<0)
3114 #define RECOUNT         (1<<1)
3115
3116 static int apply_patch(int fd, const char *filename, int options)
3117 {
3118         size_t offset;
3119         struct strbuf buf = STRBUF_INIT;
3120         struct patch *list = NULL, **listp = &list;
3121         int skipped_patch = 0;
3122
3123         /* FIXME - memory leak when using multiple patch files as inputs */
3124         memset(&fn_table, 0, sizeof(struct string_list));
3125         patch_input_file = filename;
3126         read_patch_file(&buf, fd);
3127         offset = 0;
3128         while (offset < buf.len) {
3129                 struct patch *patch;
3130                 int nr;
3131
3132                 patch = xcalloc(1, sizeof(*patch));
3133                 patch->inaccurate_eof = !!(options & INACCURATE_EOF);
3134                 patch->recount =  !!(options & RECOUNT);
3135                 nr = parse_chunk(buf.buf + offset, buf.len - offset, patch);
3136                 if (nr < 0)
3137                         break;
3138                 if (apply_in_reverse)
3139                         reverse_patches(patch);
3140                 if (prefix)
3141                         prefix_patches(patch);
3142                 if (use_patch(patch)) {
3143                         patch_stats(patch);
3144                         *listp = patch;
3145                         listp = &patch->next;
3146                 }
3147                 else {
3148                         /* perhaps free it a bit better? */
3149                         free(patch);
3150                         skipped_patch++;
3151                 }
3152                 offset += nr;
3153         }
3154
3155         if (whitespace_error && (ws_error_action == die_on_ws_error))
3156                 apply = 0;
3157
3158         update_index = check_index && apply;
3159         if (update_index && newfd < 0)
3160                 newfd = hold_locked_index(&lock_file, 1);
3161
3162         if (check_index) {
3163                 if (read_cache() < 0)
3164                         die("unable to read index file");
3165         }
3166
3167         if ((check || apply) &&
3168             check_patch_list(list) < 0 &&
3169             !apply_with_reject)
3170                 exit(1);
3171
3172         if (apply && write_out_results(list, skipped_patch))
3173                 exit(1);
3174
3175         if (fake_ancestor)
3176                 build_fake_ancestor(list, fake_ancestor);
3177
3178         if (diffstat)
3179                 stat_patch_list(list);
3180
3181         if (numstat)
3182                 numstat_patch_list(list);
3183
3184         if (summary)
3185                 summary_patch_list(list);
3186
3187         strbuf_release(&buf);
3188         return 0;
3189 }
3190
3191 static int git_apply_config(const char *var, const char *value, void *cb)
3192 {
3193         if (!strcmp(var, "apply.whitespace"))
3194                 return git_config_string(&apply_default_whitespace, var, value);
3195         return git_default_config(var, value, cb);
3196 }
3197
3198 static int option_parse_exclude(const struct option *opt,
3199                                 const char *arg, int unset)
3200 {
3201         add_name_limit(arg, 1);
3202         return 0;
3203 }
3204
3205 static int option_parse_include(const struct option *opt,
3206                                 const char *arg, int unset)
3207 {
3208         add_name_limit(arg, 0);
3209         has_include = 1;
3210         return 0;
3211 }
3212
3213 static int option_parse_p(const struct option *opt,
3214                           const char *arg, int unset)
3215 {
3216         p_value = atoi(arg);
3217         p_value_known = 1;
3218         return 0;
3219 }
3220
3221 static int option_parse_z(const struct option *opt,
3222                           const char *arg, int unset)
3223 {
3224         if (unset)
3225                 line_termination = '\n';
3226         else
3227                 line_termination = 0;
3228         return 0;
3229 }
3230
3231 static int option_parse_whitespace(const struct option *opt,
3232                                    const char *arg, int unset)
3233 {
3234         const char **whitespace_option = opt->value;
3235
3236         *whitespace_option = arg;
3237         parse_whitespace_option(arg);
3238         return 0;
3239 }
3240
3241 static int option_parse_directory(const struct option *opt,
3242                                   const char *arg, int unset)
3243 {
3244         root_len = strlen(arg);
3245         if (root_len && arg[root_len - 1] != '/') {
3246                 char *new_root;
3247                 root = new_root = xmalloc(root_len + 2);
3248                 strcpy(new_root, arg);
3249                 strcpy(new_root + root_len++, "/");
3250         } else
3251                 root = arg;
3252         return 0;
3253 }
3254
3255 int cmd_apply(int argc, const char **argv, const char *unused_prefix)
3256 {
3257         int i;
3258         int errs = 0;
3259         int is_not_gitdir;
3260         int binary;
3261         int force_apply = 0;
3262
3263         const char *whitespace_option = NULL;
3264
3265         struct option builtin_apply_options[] = {
3266                 { OPTION_CALLBACK, 0, "exclude", NULL, "path",
3267                         "don't apply changes matching the given path",
3268                         0, option_parse_exclude },
3269                 { OPTION_CALLBACK, 0, "include", NULL, "path",
3270                         "apply changes matching the given path",
3271                         0, option_parse_include },
3272                 { OPTION_CALLBACK, 'p', NULL, NULL, "num",
3273                         "remove <num> leading slashes from traditional diff paths",
3274                         0, option_parse_p },
3275                 OPT_BOOLEAN(0, "no-add", &no_add,
3276                         "ignore additions made by the patch"),
3277                 OPT_BOOLEAN(0, "stat", &diffstat,
3278                         "instead of applying the patch, output diffstat for the input"),
3279                 { OPTION_BOOLEAN, 0, "allow-binary-replacement", &binary,
3280                   NULL, "old option, now no-op",
3281                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
3282                 { OPTION_BOOLEAN, 0, "binary", &binary,
3283                   NULL, "old option, now no-op",
3284                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG },
3285                 OPT_BOOLEAN(0, "numstat", &numstat,
3286                         "shows number of added and deleted lines in decimal notation"),
3287                 OPT_BOOLEAN(0, "summary", &summary,
3288                         "instead of applying the patch, output a summary for the input"),
3289                 OPT_BOOLEAN(0, "check", &check,
3290                         "instead of applying the patch, see if the patch is applicable"),
3291                 OPT_BOOLEAN(0, "index", &check_index,
3292                         "make sure the patch is applicable to the current index"),
3293                 OPT_BOOLEAN(0, "cached", &cached,
3294                         "apply a patch without touching the working tree"),
3295                 OPT_BOOLEAN(0, "apply", &force_apply,
3296                         "also apply the patch (use with --stat/--summary/--check)"),
3297                 OPT_FILENAME(0, "build-fake-ancestor", &fake_ancestor,
3298                         "build a temporary index based on embedded index information"),
3299                 { OPTION_CALLBACK, 'z', NULL, NULL, NULL,
3300                         "paths are separated with NUL character",
3301                         PARSE_OPT_NOARG, option_parse_z },
3302                 OPT_INTEGER('C', NULL, &p_context,
3303                                 "ensure at least <n> lines of context match"),
3304                 { OPTION_CALLBACK, 0, "whitespace", &whitespace_option, "action",
3305                         "detect new or modified lines that have whitespace errors",
3306                         0, option_parse_whitespace },
3307                 OPT_BOOLEAN('R', "reverse", &apply_in_reverse,
3308                         "apply the patch in reverse"),
3309                 OPT_BOOLEAN(0, "unidiff-zero", &unidiff_zero,
3310                         "don't expect at least one line of context"),
3311                 OPT_BOOLEAN(0, "reject", &apply_with_reject,
3312                         "leave the rejected hunks in corresponding *.rej files"),
3313                 OPT__VERBOSE(&apply_verbosely),
3314                 OPT_BIT(0, "inaccurate-eof", &options,
3315                         "tolerate incorrectly detected missing new-line at the end of file",
3316                         INACCURATE_EOF),
3317                 OPT_BIT(0, "recount", &options,
3318                         "do not trust the line counts in the hunk headers",
3319                         RECOUNT),
3320                 { OPTION_CALLBACK, 0, "directory", NULL, "root",
3321                         "prepend <root> to all filenames",
3322                         0, option_parse_directory },
3323                 OPT_END()
3324         };
3325
3326         prefix = setup_git_directory_gently(&is_not_gitdir);
3327         prefix_length = prefix ? strlen(prefix) : 0;
3328         git_config(git_apply_config, NULL);
3329         if (apply_default_whitespace)
3330                 parse_whitespace_option(apply_default_whitespace);
3331
3332         argc = parse_options(argc, argv, prefix, builtin_apply_options,
3333                         apply_usage, 0);
3334
3335         if (apply_with_reject)
3336                 apply = apply_verbosely = 1;
3337         if (!force_apply && (diffstat || numstat || summary || check || fake_ancestor))
3338                 apply = 0;
3339         if (check_index && is_not_gitdir)
3340                 die("--index outside a repository");
3341         if (cached) {
3342                 if (is_not_gitdir)
3343                         die("--cached outside a repository");
3344                 check_index = 1;
3345         }
3346         for (i = 0; i < argc; i++) {
3347                 const char *arg = argv[i];
3348                 int fd;
3349
3350                 if (!strcmp(arg, "-")) {
3351                         errs |= apply_patch(0, "<stdin>", options);
3352                         read_stdin = 0;
3353                         continue;
3354                 } else if (0 < prefix_length)
3355                         arg = prefix_filename(prefix, prefix_length, arg);
3356
3357                 fd = open(arg, O_RDONLY);
3358                 if (fd < 0)
3359                         die_errno("can't open patch '%s'", arg);
3360                 read_stdin = 0;
3361                 set_default_whitespace_mode(whitespace_option);
3362                 errs |= apply_patch(fd, arg, options);
3363                 close(fd);
3364         }
3365         set_default_whitespace_mode(whitespace_option);
3366         if (read_stdin)
3367                 errs |= apply_patch(0, "<stdin>", options);
3368         if (whitespace_error) {
3369                 if (squelch_whitespace_errors &&
3370                     squelch_whitespace_errors < whitespace_error) {
3371                         int squelched =
3372                                 whitespace_error - squelch_whitespace_errors;
3373                         warning("squelched %d "
3374                                 "whitespace error%s",
3375                                 squelched,
3376                                 squelched == 1 ? "" : "s");
3377                 }
3378                 if (ws_error_action == die_on_ws_error)
3379                         die("%d line%s add%s whitespace errors.",
3380                             whitespace_error,
3381                             whitespace_error == 1 ? "" : "s",
3382                             whitespace_error == 1 ? "s" : "");
3383                 if (applied_after_fixing_ws && apply)
3384                         warning("%d line%s applied after"
3385                                 " fixing whitespace errors.",
3386                                 applied_after_fixing_ws,
3387                                 applied_after_fixing_ws == 1 ? "" : "s");
3388                 else if (whitespace_error)
3389                         warning("%d line%s add%s whitespace errors.",
3390                                 whitespace_error,
3391                                 whitespace_error == 1 ? "" : "s",
3392                                 whitespace_error == 1 ? "s" : "");
3393         }
3394
3395         if (update_index) {
3396                 if (write_cache(newfd, active_cache, active_nr) ||
3397                     commit_locked_index(&lock_file))
3398                         die("Unable to write new index file");
3399         }
3400
3401         return !!errs;
3402 }