Merge branch 'lt/rev-list'
[git] / 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 <fnmatch.h>
10 #include "cache.h"
11 #include "quote.h"
12
13 //  --check turns on checking that the working tree matches the
14 //    files that are being modified, but doesn't apply the patch
15 //  --stat does just a diffstat, and doesn't actually apply
16 //  --numstat does numeric diffstat, and doesn't actually apply
17 //  --index-info shows the old and new index info for paths if available.
18 //
19 static const char *prefix;
20 static int prefix_length = -1;
21
22 static int p_value = 1;
23 static int allow_binary_replacement = 0;
24 static int check_index = 0;
25 static int write_index = 0;
26 static int diffstat = 0;
27 static int numstat = 0;
28 static int summary = 0;
29 static int check = 0;
30 static int apply = 1;
31 static int no_add = 0;
32 static int show_index_info = 0;
33 static int line_termination = '\n';
34 static const char apply_usage[] =
35 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [-z] [-pNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
36
37 static enum whitespace_eol {
38         nowarn_whitespace,
39         warn_on_whitespace,
40         error_on_whitespace,
41         strip_whitespace,
42 } new_whitespace = warn_on_whitespace;
43 static int whitespace_error = 0;
44 static int squelch_whitespace_errors = 5;
45 static int applied_after_stripping = 0;
46 static const char *patch_input_file = NULL;
47
48 static void parse_whitespace_option(const char *option)
49 {
50         if (!option) {
51                 new_whitespace = warn_on_whitespace;
52                 return;
53         }
54         if (!strcmp(option, "warn")) {
55                 new_whitespace = warn_on_whitespace;
56                 return;
57         }
58         if (!strcmp(option, "nowarn")) {
59                 new_whitespace = nowarn_whitespace;
60                 return;
61         }
62         if (!strcmp(option, "error")) {
63                 new_whitespace = error_on_whitespace;
64                 return;
65         }
66         if (!strcmp(option, "error-all")) {
67                 new_whitespace = error_on_whitespace;
68                 squelch_whitespace_errors = 0;
69                 return;
70         }
71         if (!strcmp(option, "strip")) {
72                 new_whitespace = strip_whitespace;
73                 return;
74         }
75         die("unrecognized whitespace option '%s'", option);
76 }
77
78 static void set_default_whitespace_mode(const char *whitespace_option)
79 {
80         if (!whitespace_option && !apply_default_whitespace) {
81                 new_whitespace = (apply
82                                   ? warn_on_whitespace
83                                   : nowarn_whitespace);
84         }
85 }
86
87 /*
88  * For "diff-stat" like behaviour, we keep track of the biggest change
89  * we've seen, and the longest filename. That allows us to do simple
90  * scaling.
91  */
92 static int max_change, max_len;
93
94 /*
95  * Various "current state", notably line numbers and what
96  * file (and how) we're patching right now.. The "is_xxxx"
97  * things are flags, where -1 means "don't know yet".
98  */
99 static int linenr = 1;
100
101 struct fragment {
102         unsigned long oldpos, oldlines;
103         unsigned long newpos, newlines;
104         const char *patch;
105         int size;
106         struct fragment *next;
107 };
108
109 struct patch {
110         char *new_name, *old_name, *def_name;
111         unsigned int old_mode, new_mode;
112         int is_rename, is_copy, is_new, is_delete, is_binary;
113         int lines_added, lines_deleted;
114         int score;
115         struct fragment *fragments;
116         char *result;
117         unsigned long resultsize;
118         char old_sha1_prefix[41];
119         char new_sha1_prefix[41];
120         struct patch *next;
121 };
122
123 #define CHUNKSIZE (8192)
124 #define SLOP (16)
125
126 static void *read_patch_file(int fd, unsigned long *sizep)
127 {
128         unsigned long size = 0, alloc = CHUNKSIZE;
129         void *buffer = xmalloc(alloc);
130
131         for (;;) {
132                 int nr = alloc - size;
133                 if (nr < 1024) {
134                         alloc += CHUNKSIZE;
135                         buffer = xrealloc(buffer, alloc);
136                         nr = alloc - size;
137                 }
138                 nr = xread(fd, buffer + size, nr);
139                 if (!nr)
140                         break;
141                 if (nr < 0)
142                         die("git-apply: read returned %s", strerror(errno));
143                 size += nr;
144         }
145         *sizep = size;
146
147         /*
148          * Make sure that we have some slop in the buffer
149          * so that we can do speculative "memcmp" etc, and
150          * see to it that it is NUL-filled.
151          */
152         if (alloc < size + SLOP)
153                 buffer = xrealloc(buffer, size + SLOP);
154         memset(buffer + size, 0, SLOP);
155         return buffer;
156 }
157
158 static unsigned long linelen(const char *buffer, unsigned long size)
159 {
160         unsigned long len = 0;
161         while (size--) {
162                 len++;
163                 if (*buffer++ == '\n')
164                         break;
165         }
166         return len;
167 }
168
169 static int is_dev_null(const char *str)
170 {
171         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
172 }
173
174 #define TERM_SPACE      1
175 #define TERM_TAB        2
176
177 static int name_terminate(const char *name, int namelen, int c, int terminate)
178 {
179         if (c == ' ' && !(terminate & TERM_SPACE))
180                 return 0;
181         if (c == '\t' && !(terminate & TERM_TAB))
182                 return 0;
183
184         return 1;
185 }
186
187 static char * find_name(const char *line, char *def, int p_value, int terminate)
188 {
189         int len;
190         const char *start = line;
191         char *name;
192
193         if (*line == '"') {
194                 /* Proposed "new-style" GNU patch/diff format; see
195                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
196                  */
197                 name = unquote_c_style(line, NULL);
198                 if (name) {
199                         char *cp = name;
200                         while (p_value) {
201                                 cp = strchr(name, '/');
202                                 if (!cp)
203                                         break;
204                                 cp++;
205                                 p_value--;
206                         }
207                         if (cp) {
208                                 /* name can later be freed, so we need
209                                  * to memmove, not just return cp
210                                  */
211                                 memmove(name, cp, strlen(cp) + 1);
212                                 free(def);
213                                 return name;
214                         }
215                         else {
216                                 free(name);
217                                 name = NULL;
218                         }
219                 }
220         }
221
222         for (;;) {
223                 char c = *line;
224
225                 if (isspace(c)) {
226                         if (c == '\n')
227                                 break;
228                         if (name_terminate(start, line-start, c, terminate))
229                                 break;
230                 }
231                 line++;
232                 if (c == '/' && !--p_value)
233                         start = line;
234         }
235         if (!start)
236                 return def;
237         len = line - start;
238         if (!len)
239                 return def;
240
241         /*
242          * Generally we prefer the shorter name, especially
243          * if the other one is just a variation of that with
244          * something else tacked on to the end (ie "file.orig"
245          * or "file~").
246          */
247         if (def) {
248                 int deflen = strlen(def);
249                 if (deflen < len && !strncmp(start, def, deflen))
250                         return def;
251         }
252
253         name = xmalloc(len + 1);
254         memcpy(name, start, len);
255         name[len] = 0;
256         free(def);
257         return name;
258 }
259
260 /*
261  * Get the name etc info from the --/+++ lines of a traditional patch header
262  *
263  * NOTE! This hardcodes "-p1" behaviour in filename detection.
264  *
265  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
266  * files, we can happily check the index for a match, but for creating a
267  * new file we should try to match whatever "patch" does. I have no idea.
268  */
269 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
270 {
271         char *name;
272
273         first += 4;     // skip "--- "
274         second += 4;    // skip "+++ "
275         if (is_dev_null(first)) {
276                 patch->is_new = 1;
277                 patch->is_delete = 0;
278                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
279                 patch->new_name = name;
280         } else if (is_dev_null(second)) {
281                 patch->is_new = 0;
282                 patch->is_delete = 1;
283                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
284                 patch->old_name = name;
285         } else {
286                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
287                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
288                 patch->old_name = patch->new_name = name;
289         }
290         if (!name)
291                 die("unable to find filename in patch at line %d", linenr);
292 }
293
294 static int gitdiff_hdrend(const char *line, struct patch *patch)
295 {
296         return -1;
297 }
298
299 /*
300  * We're anal about diff header consistency, to make
301  * sure that we don't end up having strange ambiguous
302  * patches floating around.
303  *
304  * As a result, gitdiff_{old|new}name() will check
305  * their names against any previous information, just
306  * to make sure..
307  */
308 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
309 {
310         if (!orig_name && !isnull)
311                 return find_name(line, NULL, 1, 0);
312
313         if (orig_name) {
314                 int len;
315                 const char *name;
316                 char *another;
317                 name = orig_name;
318                 len = strlen(name);
319                 if (isnull)
320                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
321                 another = find_name(line, NULL, 1, 0);
322                 if (!another || memcmp(another, name, len))
323                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
324                 free(another);
325                 return orig_name;
326         }
327         else {
328                 /* expect "/dev/null" */
329                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
330                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
331                 return NULL;
332         }
333 }
334
335 static int gitdiff_oldname(const char *line, struct patch *patch)
336 {
337         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
338         return 0;
339 }
340
341 static int gitdiff_newname(const char *line, struct patch *patch)
342 {
343         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
344         return 0;
345 }
346
347 static int gitdiff_oldmode(const char *line, struct patch *patch)
348 {
349         patch->old_mode = strtoul(line, NULL, 8);
350         return 0;
351 }
352
353 static int gitdiff_newmode(const char *line, struct patch *patch)
354 {
355         patch->new_mode = strtoul(line, NULL, 8);
356         return 0;
357 }
358
359 static int gitdiff_delete(const char *line, struct patch *patch)
360 {
361         patch->is_delete = 1;
362         patch->old_name = patch->def_name;
363         return gitdiff_oldmode(line, patch);
364 }
365
366 static int gitdiff_newfile(const char *line, struct patch *patch)
367 {
368         patch->is_new = 1;
369         patch->new_name = patch->def_name;
370         return gitdiff_newmode(line, patch);
371 }
372
373 static int gitdiff_copysrc(const char *line, struct patch *patch)
374 {
375         patch->is_copy = 1;
376         patch->old_name = find_name(line, NULL, 0, 0);
377         return 0;
378 }
379
380 static int gitdiff_copydst(const char *line, struct patch *patch)
381 {
382         patch->is_copy = 1;
383         patch->new_name = find_name(line, NULL, 0, 0);
384         return 0;
385 }
386
387 static int gitdiff_renamesrc(const char *line, struct patch *patch)
388 {
389         patch->is_rename = 1;
390         patch->old_name = find_name(line, NULL, 0, 0);
391         return 0;
392 }
393
394 static int gitdiff_renamedst(const char *line, struct patch *patch)
395 {
396         patch->is_rename = 1;
397         patch->new_name = find_name(line, NULL, 0, 0);
398         return 0;
399 }
400
401 static int gitdiff_similarity(const char *line, struct patch *patch)
402 {
403         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
404                 patch->score = 0;
405         return 0;
406 }
407
408 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
409 {
410         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
411                 patch->score = 0;
412         return 0;
413 }
414
415 static int gitdiff_index(const char *line, struct patch *patch)
416 {
417         /* index line is N hexadecimal, "..", N hexadecimal,
418          * and optional space with octal mode.
419          */
420         const char *ptr, *eol;
421         int len;
422
423         ptr = strchr(line, '.');
424         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
425                 return 0;
426         len = ptr - line;
427         memcpy(patch->old_sha1_prefix, line, len);
428         patch->old_sha1_prefix[len] = 0;
429
430         line = ptr + 2;
431         ptr = strchr(line, ' ');
432         eol = strchr(line, '\n');
433
434         if (!ptr || eol < ptr)
435                 ptr = eol;
436         len = ptr - line;
437
438         if (40 < len)
439                 return 0;
440         memcpy(patch->new_sha1_prefix, line, len);
441         patch->new_sha1_prefix[len] = 0;
442         if (*ptr == ' ')
443                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
444         return 0;
445 }
446
447 /*
448  * This is normal for a diff that doesn't change anything: we'll fall through
449  * into the next diff. Tell the parser to break out.
450  */
451 static int gitdiff_unrecognized(const char *line, struct patch *patch)
452 {
453         return -1;
454 }
455
456 static const char *stop_at_slash(const char *line, int llen)
457 {
458         int i;
459
460         for (i = 0; i < llen; i++) {
461                 int ch = line[i];
462                 if (ch == '/')
463                         return line + i;
464         }
465         return NULL;
466 }
467
468 /* This is to extract the same name that appears on "diff --git"
469  * line.  We do not find and return anything if it is a rename
470  * patch, and it is OK because we will find the name elsewhere.
471  * We need to reliably find name only when it is mode-change only,
472  * creation or deletion of an empty file.  In any of these cases,
473  * both sides are the same name under a/ and b/ respectively.
474  */
475 static char *git_header_name(char *line, int llen)
476 {
477         int len;
478         const char *name;
479         const char *second = NULL;
480
481         line += strlen("diff --git ");
482         llen -= strlen("diff --git ");
483
484         if (*line == '"') {
485                 const char *cp;
486                 char *first = unquote_c_style(line, &second);
487                 if (!first)
488                         return NULL;
489
490                 /* advance to the first slash */
491                 cp = stop_at_slash(first, strlen(first));
492                 if (!cp || cp == first) {
493                         /* we do not accept absolute paths */
494                 free_first_and_fail:
495                         free(first);
496                         return NULL;
497                 }
498                 len = strlen(cp+1);
499                 memmove(first, cp+1, len+1); /* including NUL */
500
501                 /* second points at one past closing dq of name.
502                  * find the second name.
503                  */
504                 while ((second < line + llen) && isspace(*second))
505                         second++;
506
507                 if (line + llen <= second)
508                         goto free_first_and_fail;
509                 if (*second == '"') {
510                         char *sp = unquote_c_style(second, NULL);
511                         if (!sp)
512                                 goto free_first_and_fail;
513                         cp = stop_at_slash(sp, strlen(sp));
514                         if (!cp || cp == sp) {
515                         free_both_and_fail:
516                                 free(sp);
517                                 goto free_first_and_fail;
518                         }
519                         /* They must match, otherwise ignore */
520                         if (strcmp(cp+1, first))
521                                 goto free_both_and_fail;
522                         free(sp);
523                         return first;
524                 }
525
526                 /* unquoted second */
527                 cp = stop_at_slash(second, line + llen - second);
528                 if (!cp || cp == second)
529                         goto free_first_and_fail;
530                 cp++;
531                 if (line + llen - cp != len + 1 ||
532                     memcmp(first, cp, len))
533                         goto free_first_and_fail;
534                 return first;
535         }
536
537         /* unquoted first name */
538         name = stop_at_slash(line, llen);
539         if (!name || name == line)
540                 return NULL;
541
542         name++;
543
544         /* since the first name is unquoted, a dq if exists must be
545          * the beginning of the second name.
546          */
547         for (second = name; second < line + llen; second++) {
548                 if (*second == '"') {
549                         const char *cp = second;
550                         const char *np;
551                         char *sp = unquote_c_style(second, NULL);
552
553                         if (!sp)
554                                 return NULL;
555                         np = stop_at_slash(sp, strlen(sp));
556                         if (!np || np == sp) {
557                         free_second_and_fail:
558                                 free(sp);
559                                 return NULL;
560                         }
561                         np++;
562                         len = strlen(np);
563                         if (len < cp - name &&
564                             !strncmp(np, name, len) &&
565                             isspace(name[len])) {
566                                 /* Good */
567                                 memmove(sp, np, len + 1);
568                                 return sp;
569                         }
570                         goto free_second_and_fail;
571                 }
572         }
573
574         /*
575          * Accept a name only if it shows up twice, exactly the same
576          * form.
577          */
578         for (len = 0 ; ; len++) {
579                 char c = name[len];
580
581                 switch (c) {
582                 default:
583                         continue;
584                 case '\n':
585                         return NULL;
586                 case '\t': case ' ':
587                         second = name+len;
588                         for (;;) {
589                                 char c = *second++;
590                                 if (c == '\n')
591                                         return NULL;
592                                 if (c == '/')
593                                         break;
594                         }
595                         if (second[len] == '\n' && !memcmp(name, second, len)) {
596                                 char *ret = xmalloc(len + 1);
597                                 memcpy(ret, name, len);
598                                 ret[len] = 0;
599                                 return ret;
600                         }
601                 }
602         }
603         return NULL;
604 }
605
606 /* Verify that we recognize the lines following a git header */
607 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
608 {
609         unsigned long offset;
610
611         /* A git diff has explicit new/delete information, so we don't guess */
612         patch->is_new = 0;
613         patch->is_delete = 0;
614
615         /*
616          * Some things may not have the old name in the
617          * rest of the headers anywhere (pure mode changes,
618          * or removing or adding empty files), so we get
619          * the default name from the header.
620          */
621         patch->def_name = git_header_name(line, len);
622
623         line += len;
624         size -= len;
625         linenr++;
626         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
627                 static const struct opentry {
628                         const char *str;
629                         int (*fn)(const char *, struct patch *);
630                 } optable[] = {
631                         { "@@ -", gitdiff_hdrend },
632                         { "--- ", gitdiff_oldname },
633                         { "+++ ", gitdiff_newname },
634                         { "old mode ", gitdiff_oldmode },
635                         { "new mode ", gitdiff_newmode },
636                         { "deleted file mode ", gitdiff_delete },
637                         { "new file mode ", gitdiff_newfile },
638                         { "copy from ", gitdiff_copysrc },
639                         { "copy to ", gitdiff_copydst },
640                         { "rename old ", gitdiff_renamesrc },
641                         { "rename new ", gitdiff_renamedst },
642                         { "rename from ", gitdiff_renamesrc },
643                         { "rename to ", gitdiff_renamedst },
644                         { "similarity index ", gitdiff_similarity },
645                         { "dissimilarity index ", gitdiff_dissimilarity },
646                         { "index ", gitdiff_index },
647                         { "", gitdiff_unrecognized },
648                 };
649                 int i;
650
651                 len = linelen(line, size);
652                 if (!len || line[len-1] != '\n')
653                         break;
654                 for (i = 0; i < sizeof(optable) / sizeof(optable[0]); i++) {
655                         const struct opentry *p = optable + i;
656                         int oplen = strlen(p->str);
657                         if (len < oplen || memcmp(p->str, line, oplen))
658                                 continue;
659                         if (p->fn(line + oplen, patch) < 0)
660                                 return offset;
661                         break;
662                 }
663         }
664
665         return offset;
666 }
667
668 static int parse_num(const char *line, unsigned long *p)
669 {
670         char *ptr;
671
672         if (!isdigit(*line))
673                 return 0;
674         *p = strtoul(line, &ptr, 10);
675         return ptr - line;
676 }
677
678 static int parse_range(const char *line, int len, int offset, const char *expect,
679                         unsigned long *p1, unsigned long *p2)
680 {
681         int digits, ex;
682
683         if (offset < 0 || offset >= len)
684                 return -1;
685         line += offset;
686         len -= offset;
687
688         digits = parse_num(line, p1);
689         if (!digits)
690                 return -1;
691
692         offset += digits;
693         line += digits;
694         len -= digits;
695
696         *p2 = *p1;
697         if (*line == ',') {
698                 digits = parse_num(line+1, p2);
699                 if (!digits)
700                         return -1;
701
702                 offset += digits+1;
703                 line += digits+1;
704                 len -= digits+1;
705         }
706
707         ex = strlen(expect);
708         if (ex > len)
709                 return -1;
710         if (memcmp(line, expect, ex))
711                 return -1;
712
713         return offset + ex;
714 }
715
716 /*
717  * Parse a unified diff fragment header of the
718  * form "@@ -a,b +c,d @@"
719  */
720 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
721 {
722         int offset;
723
724         if (!len || line[len-1] != '\n')
725                 return -1;
726
727         /* Figure out the number of lines in a fragment */
728         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
729         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
730
731         return offset;
732 }
733
734 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
735 {
736         unsigned long offset, len;
737
738         patch->is_rename = patch->is_copy = 0;
739         patch->is_new = patch->is_delete = -1;
740         patch->old_mode = patch->new_mode = 0;
741         patch->old_name = patch->new_name = NULL;
742         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
743                 unsigned long nextlen;
744
745                 len = linelen(line, size);
746                 if (!len)
747                         break;
748
749                 /* Testing this early allows us to take a few shortcuts.. */
750                 if (len < 6)
751                         continue;
752
753                 /*
754                  * Make sure we don't find any unconnected patch fragmants.
755                  * That's a sign that we didn't find a header, and that a
756                  * patch has become corrupted/broken up.
757                  */
758                 if (!memcmp("@@ -", line, 4)) {
759                         struct fragment dummy;
760                         if (parse_fragment_header(line, len, &dummy) < 0)
761                                 continue;
762                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
763                 }
764
765                 if (size < len + 6)
766                         break;
767
768                 /*
769                  * Git patch? It might not have a real patch, just a rename
770                  * or mode change, so we handle that specially
771                  */
772                 if (!memcmp("diff --git ", line, 11)) {
773                         int git_hdr_len = parse_git_header(line, len, size, patch);
774                         if (git_hdr_len <= len)
775                                 continue;
776                         if (!patch->old_name && !patch->new_name) {
777                                 if (!patch->def_name)
778                                         die("git diff header lacks filename information (line %d)", linenr);
779                                 patch->old_name = patch->new_name = patch->def_name;
780                         }
781                         *hdrsize = git_hdr_len;
782                         return offset;
783                 }
784
785                 /** --- followed by +++ ? */
786                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
787                         continue;
788
789                 /*
790                  * We only accept unified patches, so we want it to
791                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
792                  * minimum
793                  */
794                 nextlen = linelen(line + len, size - len);
795                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
796                         continue;
797
798                 /* Ok, we'll consider it a patch */
799                 parse_traditional_patch(line, line+len, patch);
800                 *hdrsize = len + nextlen;
801                 linenr += 2;
802                 return offset;
803         }
804         return -1;
805 }
806
807 /*
808  * Parse a unified diff. Note that this really needs
809  * to parse each fragment separately, since the only
810  * way to know the difference between a "---" that is
811  * part of a patch, and a "---" that starts the next
812  * patch is to look at the line counts..
813  */
814 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
815 {
816         int added, deleted;
817         int len = linelen(line, size), offset;
818         unsigned long oldlines, newlines;
819
820         offset = parse_fragment_header(line, len, fragment);
821         if (offset < 0)
822                 return -1;
823         oldlines = fragment->oldlines;
824         newlines = fragment->newlines;
825
826         if (patch->is_new < 0) {
827                 patch->is_new =  !oldlines;
828                 if (!oldlines)
829                         patch->old_name = NULL;
830         }
831         if (patch->is_delete < 0) {
832                 patch->is_delete = !newlines;
833                 if (!newlines)
834                         patch->new_name = NULL;
835         }
836
837         if (patch->is_new != !oldlines)
838                 return error("new file depends on old contents");
839         if (patch->is_delete != !newlines) {
840                 if (newlines)
841                         return error("deleted file still has contents");
842                 fprintf(stderr, "** warning: file %s becomes empty but is not deleted\n", patch->new_name);
843         }
844
845         /* Parse the thing.. */
846         line += len;
847         size -= len;
848         linenr++;
849         added = deleted = 0;
850         for (offset = len; size > 0; offset += len, size -= len, line += len, linenr++) {
851                 if (!oldlines && !newlines)
852                         break;
853                 len = linelen(line, size);
854                 if (!len || line[len-1] != '\n')
855                         return -1;
856                 switch (*line) {
857                 default:
858                         return -1;
859                 case ' ':
860                         oldlines--;
861                         newlines--;
862                         break;
863                 case '-':
864                         deleted++;
865                         oldlines--;
866                         break;
867                 case '+':
868                         /*
869                          * We know len is at least two, since we have a '+' and
870                          * we checked that the last character was a '\n' above.
871                          * That is, an addition of an empty line would check
872                          * the '+' here.  Sneaky...
873                          */
874                         if ((new_whitespace != nowarn_whitespace) &&
875                             isspace(line[len-2])) {
876                                 whitespace_error++;
877                                 if (squelch_whitespace_errors &&
878                                     squelch_whitespace_errors <
879                                     whitespace_error)
880                                         ;
881                                 else {
882                                         fprintf(stderr, "Adds trailing whitespace.\n%s:%d:%.*s\n",
883                                                 patch_input_file,
884                                                 linenr, len-2, line+1);
885                                 }
886                         }
887                         added++;
888                         newlines--;
889                         break;
890
891                 /* We allow "\ No newline at end of file". Depending
892                  * on locale settings when the patch was produced we
893                  * don't know what this line looks like. The only
894                  * thing we do know is that it begins with "\ ".
895                  * Checking for 12 is just for sanity check -- any
896                  * l10n of "\ No newline..." is at least that long.
897                  */
898                 case '\\':
899                         if (len < 12 || memcmp(line, "\\ ", 2))
900                                 return -1;
901                         break;
902                 }
903         }
904         /* If a fragment ends with an incomplete line, we failed to include
905          * it in the above loop because we hit oldlines == newlines == 0
906          * before seeing it.
907          */
908         if (12 < size && !memcmp(line, "\\ ", 2))
909                 offset += linelen(line, size);
910
911         patch->lines_added += added;
912         patch->lines_deleted += deleted;
913         return offset;
914 }
915
916 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
917 {
918         unsigned long offset = 0;
919         struct fragment **fragp = &patch->fragments;
920
921         while (size > 4 && !memcmp(line, "@@ -", 4)) {
922                 struct fragment *fragment;
923                 int len;
924
925                 fragment = xmalloc(sizeof(*fragment));
926                 memset(fragment, 0, sizeof(*fragment));
927                 len = parse_fragment(line, size, patch, fragment);
928                 if (len <= 0)
929                         die("corrupt patch at line %d", linenr);
930
931                 fragment->patch = line;
932                 fragment->size = len;
933
934                 *fragp = fragment;
935                 fragp = &fragment->next;
936
937                 offset += len;
938                 line += len;
939                 size -= len;
940         }
941         return offset;
942 }
943
944 static inline int metadata_changes(struct patch *patch)
945 {
946         return  patch->is_rename > 0 ||
947                 patch->is_copy > 0 ||
948                 patch->is_new > 0 ||
949                 patch->is_delete ||
950                 (patch->old_mode && patch->new_mode &&
951                  patch->old_mode != patch->new_mode);
952 }
953
954 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
955 {
956         int hdrsize, patchsize;
957         int offset = find_header(buffer, size, &hdrsize, patch);
958
959         if (offset < 0)
960                 return offset;
961
962         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
963
964         if (!patchsize) {
965                 static const char *binhdr[] = {
966                         "Binary files ",
967                         "Files ",
968                         NULL,
969                 };
970                 int i;
971                 int hd = hdrsize + offset;
972                 unsigned long llen = linelen(buffer + hd, size - hd);
973
974                 if (!memcmp(" differ\n", buffer + hd + llen - 8, 8))
975                         for (i = 0; binhdr[i]; i++) {
976                                 int len = strlen(binhdr[i]);
977                                 if (len < size - hd &&
978                                     !memcmp(binhdr[i], buffer + hd, len)) {
979                                         patch->is_binary = 1;
980                                         break;
981                                 }
982                         }
983
984                 /* Empty patch cannot be applied if:
985                  * - it is a binary patch and we do not do binary_replace, or
986                  * - text patch without metadata change
987                  */
988                 if ((apply || check) &&
989                     (patch->is_binary
990                      ? !allow_binary_replacement
991                      : !metadata_changes(patch)))
992                         die("patch with only garbage at line %d", linenr);
993         }
994
995         return offset + hdrsize + patchsize;
996 }
997
998 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
999 static const char minuses[]= "----------------------------------------------------------------------";
1000
1001 static void show_stats(struct patch *patch)
1002 {
1003         const char *prefix = "";
1004         char *name = patch->new_name;
1005         char *qname = NULL;
1006         int len, max, add, del, total;
1007
1008         if (!name)
1009                 name = patch->old_name;
1010
1011         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1012                 qname = xmalloc(len + 1);
1013                 quote_c_style(name, qname, NULL, 0);
1014                 name = qname;
1015         }
1016
1017         /*
1018          * "scale" the filename
1019          */
1020         len = strlen(name);
1021         max = max_len;
1022         if (max > 50)
1023                 max = 50;
1024         if (len > max) {
1025                 char *slash;
1026                 prefix = "...";
1027                 max -= 3;
1028                 name += len - max;
1029                 slash = strchr(name, '/');
1030                 if (slash)
1031                         name = slash;
1032         }
1033         len = max;
1034
1035         /*
1036          * scale the add/delete
1037          */
1038         max = max_change;
1039         if (max + len > 70)
1040                 max = 70 - len;
1041
1042         add = patch->lines_added;
1043         del = patch->lines_deleted;
1044         total = add + del;
1045
1046         if (max_change > 0) {
1047                 total = (total * max + max_change / 2) / max_change;
1048                 add = (add * max + max_change / 2) / max_change;
1049                 del = total - add;
1050         }
1051         if (patch->is_binary)
1052                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1053         else
1054                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1055                        len, name, patch->lines_added + patch->lines_deleted,
1056                        add, pluses, del, minuses);
1057         if (qname)
1058                 free(qname);
1059 }
1060
1061 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1062 {
1063         int fd;
1064         unsigned long got;
1065
1066         switch (st->st_mode & S_IFMT) {
1067         case S_IFLNK:
1068                 return readlink(path, buf, size);
1069         case S_IFREG:
1070                 fd = open(path, O_RDONLY);
1071                 if (fd < 0)
1072                         return error("unable to open %s", path);
1073                 got = 0;
1074                 for (;;) {
1075                         int ret = xread(fd, buf + got, size - got);
1076                         if (ret <= 0)
1077                                 break;
1078                         got += ret;
1079                 }
1080                 close(fd);
1081                 return got;
1082
1083         default:
1084                 return -1;
1085         }
1086 }
1087
1088 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line)
1089 {
1090         int i;
1091         unsigned long start, backwards, forwards;
1092
1093         if (fragsize > size)
1094                 return -1;
1095
1096         start = 0;
1097         if (line > 1) {
1098                 unsigned long offset = 0;
1099                 i = line-1;
1100                 while (offset + fragsize <= size) {
1101                         if (buf[offset++] == '\n') {
1102                                 start = offset;
1103                                 if (!--i)
1104                                         break;
1105                         }
1106                 }
1107         }
1108
1109         /* Exact line number? */
1110         if (!memcmp(buf + start, fragment, fragsize))
1111                 return start;
1112
1113         /*
1114          * There's probably some smart way to do this, but I'll leave
1115          * that to the smart and beautiful people. I'm simple and stupid.
1116          */
1117         backwards = start;
1118         forwards = start;
1119         for (i = 0; ; i++) {
1120                 unsigned long try;
1121                 int n;
1122
1123                 /* "backward" */
1124                 if (i & 1) {
1125                         if (!backwards) {
1126                                 if (forwards + fragsize > size)
1127                                         break;
1128                                 continue;
1129                         }
1130                         do {
1131                                 --backwards;
1132                         } while (backwards && buf[backwards-1] != '\n');
1133                         try = backwards;
1134                 } else {
1135                         while (forwards + fragsize <= size) {
1136                                 if (buf[forwards++] == '\n')
1137                                         break;
1138                         }
1139                         try = forwards;
1140                 }
1141
1142                 if (try + fragsize > size)
1143                         continue;
1144                 if (memcmp(buf + try, fragment, fragsize))
1145                         continue;
1146                 n = (i >> 1)+1;
1147                 if (i & 1)
1148                         n = -n;
1149                 return try;
1150         }
1151
1152         /*
1153          * We should start searching forward and backward.
1154          */
1155         return -1;
1156 }
1157
1158 struct buffer_desc {
1159         char *buffer;
1160         unsigned long size;
1161         unsigned long alloc;
1162 };
1163
1164 static int apply_line(char *output, const char *patch, int plen)
1165 {
1166         /* plen is number of bytes to be copied from patch,
1167          * starting at patch+1 (patch[0] is '+').  Typically
1168          * patch[plen] is '\n'.
1169          */
1170         int add_nl_to_tail = 0;
1171         if ((new_whitespace == strip_whitespace) &&
1172             1 < plen && isspace(patch[plen-1])) {
1173                 if (patch[plen] == '\n')
1174                         add_nl_to_tail = 1;
1175                 plen--;
1176                 while (0 < plen && isspace(patch[plen]))
1177                         plen--;
1178                 applied_after_stripping++;
1179         }
1180         memcpy(output, patch + 1, plen);
1181         if (add_nl_to_tail)
1182                 output[plen++] = '\n';
1183         return plen;
1184 }
1185
1186 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag)
1187 {
1188         char *buf = desc->buffer;
1189         const char *patch = frag->patch;
1190         int offset, size = frag->size;
1191         char *old = xmalloc(size);
1192         char *new = xmalloc(size);
1193         int oldsize = 0, newsize = 0;
1194
1195         while (size > 0) {
1196                 int len = linelen(patch, size);
1197                 int plen;
1198
1199                 if (!len)
1200                         break;
1201
1202                 /*
1203                  * "plen" is how much of the line we should use for
1204                  * the actual patch data. Normally we just remove the
1205                  * first character on the line, but if the line is
1206                  * followed by "\ No newline", then we also remove the
1207                  * last one (which is the newline, of course).
1208                  */
1209                 plen = len-1;
1210                 if (len < size && patch[len] == '\\')
1211                         plen--;
1212                 switch (*patch) {
1213                 case ' ':
1214                 case '-':
1215                         memcpy(old + oldsize, patch + 1, plen);
1216                         oldsize += plen;
1217                         if (*patch == '-')
1218                                 break;
1219                 /* Fall-through for ' ' */
1220                 case '+':
1221                         if (*patch != '+' || !no_add)
1222                                 newsize += apply_line(new + newsize, patch,
1223                                                       plen);
1224                         break;
1225                 case '@': case '\\':
1226                         /* Ignore it, we already handled it */
1227                         break;
1228                 default:
1229                         return -1;
1230                 }
1231                 patch += len;
1232                 size -= len;
1233         }
1234
1235 #ifdef NO_ACCURATE_DIFF
1236         if (oldsize > 0 && old[oldsize - 1] == '\n' &&
1237                         newsize > 0 && new[newsize - 1] == '\n') {
1238                 oldsize--;
1239                 newsize--;
1240         }
1241 #endif
1242                         
1243         offset = find_offset(buf, desc->size, old, oldsize, frag->newpos);
1244         if (offset >= 0) {
1245                 int diff = newsize - oldsize;
1246                 unsigned long size = desc->size + diff;
1247                 unsigned long alloc = desc->alloc;
1248
1249                 if (size > alloc) {
1250                         alloc = size + 8192;
1251                         desc->alloc = alloc;
1252                         buf = xrealloc(buf, alloc);
1253                         desc->buffer = buf;
1254                 }
1255                 desc->size = size;
1256                 memmove(buf + offset + newsize, buf + offset + oldsize, size - offset - newsize);
1257                 memcpy(buf + offset, new, newsize);
1258                 offset = 0;
1259         }
1260
1261         free(old);
1262         free(new);
1263         return offset;
1264 }
1265
1266 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1267 {
1268         struct fragment *frag = patch->fragments;
1269         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1270
1271         if (patch->is_binary) {
1272                 unsigned char sha1[20];
1273
1274                 if (!allow_binary_replacement)
1275                         return error("cannot apply binary patch to '%s' "
1276                                      "without --allow-binary-replacement",
1277                                      name);
1278
1279                 /* For safety, we require patch index line to contain
1280                  * full 40-byte textual SHA1 for old and new, at least for now.
1281                  */
1282                 if (strlen(patch->old_sha1_prefix) != 40 ||
1283                     strlen(patch->new_sha1_prefix) != 40 ||
1284                     get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1285                     get_sha1_hex(patch->new_sha1_prefix, sha1))
1286                         return error("cannot apply binary patch to '%s' "
1287                                      "without full index line", name);
1288
1289                 if (patch->old_name) {
1290                         unsigned char hdr[50];
1291                         int hdrlen;
1292
1293                         /* See if the old one matches what the patch
1294                          * applies to.
1295                          */
1296                         write_sha1_file_prepare(desc->buffer, desc->size,
1297                                                 "blob", sha1, hdr, &hdrlen);
1298                         if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1299                                 return error("the patch applies to '%s' (%s), "
1300                                              "which does not match the "
1301                                              "current contents.",
1302                                              name, sha1_to_hex(sha1));
1303                 }
1304                 else {
1305                         /* Otherwise, the old one must be empty. */
1306                         if (desc->size)
1307                                 return error("the patch applies to an empty "
1308                                              "'%s' but it is not empty", name);
1309                 }
1310
1311                 /* For now, we do not record post-image data in the patch,
1312                  * and require the object already present in the recipient's
1313                  * object database.
1314                  */
1315                 if (desc->buffer) {
1316                         free(desc->buffer);
1317                         desc->alloc = desc->size = 0;
1318                 }
1319                 get_sha1_hex(patch->new_sha1_prefix, sha1);
1320
1321                 if (memcmp(sha1, null_sha1, 20)) {
1322                         char type[10];
1323                         unsigned long size;
1324
1325                         desc->buffer = read_sha1_file(sha1, type, &size);
1326                         if (!desc->buffer)
1327                                 return error("the necessary postimage %s for "
1328                                              "'%s' does not exist",
1329                                              patch->new_sha1_prefix, name);
1330                         desc->alloc = desc->size = size;
1331                 }
1332
1333                 return 0;
1334         }
1335
1336         while (frag) {
1337                 if (apply_one_fragment(desc, frag) < 0)
1338                         return error("patch failed: %s:%ld",
1339                                      name, frag->oldpos);
1340                 frag = frag->next;
1341         }
1342         return 0;
1343 }
1344
1345 static int apply_data(struct patch *patch, struct stat *st)
1346 {
1347         char *buf;
1348         unsigned long size, alloc;
1349         struct buffer_desc desc;
1350
1351         size = 0;
1352         alloc = 0;
1353         buf = NULL;
1354         if (patch->old_name) {
1355                 size = st->st_size;
1356                 alloc = size + 8192;
1357                 buf = xmalloc(alloc);
1358                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1359                         return error("read of %s failed", patch->old_name);
1360         }
1361
1362         desc.size = size;
1363         desc.alloc = alloc;
1364         desc.buffer = buf;
1365         if (apply_fragments(&desc, patch) < 0)
1366                 return -1;
1367         patch->result = desc.buffer;
1368         patch->resultsize = desc.size;
1369
1370         if (patch->is_delete && patch->resultsize)
1371                 return error("removal patch leaves file contents");
1372
1373         return 0;
1374 }
1375
1376 static int check_patch(struct patch *patch)
1377 {
1378         struct stat st;
1379         const char *old_name = patch->old_name;
1380         const char *new_name = patch->new_name;
1381         const char *name = old_name ? old_name : new_name;
1382
1383         if (old_name) {
1384                 int changed;
1385                 int stat_ret = lstat(old_name, &st);
1386
1387                 if (check_index) {
1388                         int pos = cache_name_pos(old_name, strlen(old_name));
1389                         if (pos < 0)
1390                                 return error("%s: does not exist in index",
1391                                              old_name);
1392                         if (stat_ret < 0) {
1393                                 struct checkout costate;
1394                                 if (errno != ENOENT)
1395                                         return error("%s: %s", old_name,
1396                                                      strerror(errno));
1397                                 /* checkout */
1398                                 costate.base_dir = "";
1399                                 costate.base_dir_len = 0;
1400                                 costate.force = 0;
1401                                 costate.quiet = 0;
1402                                 costate.not_new = 0;
1403                                 costate.refresh_cache = 1;
1404                                 if (checkout_entry(active_cache[pos],
1405                                                    &costate) ||
1406                                     lstat(old_name, &st))
1407                                         return -1;
1408                         }
1409
1410                         changed = ce_match_stat(active_cache[pos], &st, 1);
1411                         if (changed)
1412                                 return error("%s: does not match index",
1413                                              old_name);
1414                 }
1415                 else if (stat_ret < 0)
1416                         return error("%s: %s", old_name, strerror(errno));
1417
1418                 if (patch->is_new < 0)
1419                         patch->is_new = 0;
1420                 st.st_mode = ntohl(create_ce_mode(st.st_mode));
1421                 if (!patch->old_mode)
1422                         patch->old_mode = st.st_mode;
1423                 if ((st.st_mode ^ patch->old_mode) & S_IFMT)
1424                         return error("%s: wrong type", old_name);
1425                 if (st.st_mode != patch->old_mode)
1426                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1427                                 old_name, st.st_mode, patch->old_mode);
1428         }
1429
1430         if (new_name && (patch->is_new | patch->is_rename | patch->is_copy)) {
1431                 if (check_index && cache_name_pos(new_name, strlen(new_name)) >= 0)
1432                         return error("%s: already exists in index", new_name);
1433                 if (!lstat(new_name, &st))
1434                         return error("%s: already exists in working directory", new_name);
1435                 if (errno != ENOENT)
1436                         return error("%s: %s", new_name, strerror(errno));
1437                 if (!patch->new_mode) {
1438                         if (patch->is_new)
1439                                 patch->new_mode = S_IFREG | 0644;
1440                         else
1441                                 patch->new_mode = patch->old_mode;
1442                 }
1443         }
1444
1445         if (new_name && old_name) {
1446                 int same = !strcmp(old_name, new_name);
1447                 if (!patch->new_mode)
1448                         patch->new_mode = patch->old_mode;
1449                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
1450                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
1451                                 patch->new_mode, new_name, patch->old_mode,
1452                                 same ? "" : " of ", same ? "" : old_name);
1453         }       
1454
1455         if (apply_data(patch, &st) < 0)
1456                 return error("%s: patch does not apply", name);
1457         return 0;
1458 }
1459
1460 static int check_patch_list(struct patch *patch)
1461 {
1462         int error = 0;
1463
1464         for (;patch ; patch = patch->next)
1465                 error |= check_patch(patch);
1466         return error;
1467 }
1468
1469 static inline int is_null_sha1(const unsigned char *sha1)
1470 {
1471         return !memcmp(sha1, null_sha1, 20);
1472 }
1473
1474 static void show_index_list(struct patch *list)
1475 {
1476         struct patch *patch;
1477
1478         /* Once we start supporting the reverse patch, it may be
1479          * worth showing the new sha1 prefix, but until then...
1480          */
1481         for (patch = list; patch; patch = patch->next) {
1482                 const unsigned char *sha1_ptr;
1483                 unsigned char sha1[20];
1484                 const char *name;
1485
1486                 name = patch->old_name ? patch->old_name : patch->new_name;
1487                 if (patch->is_new)
1488                         sha1_ptr = null_sha1;
1489                 else if (get_sha1(patch->old_sha1_prefix, sha1))
1490                         die("sha1 information is lacking or useless (%s).",
1491                             name);
1492                 else
1493                         sha1_ptr = sha1;
1494
1495                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
1496                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1497                         quote_c_style(name, NULL, stdout, 0);
1498                 else
1499                         fputs(name, stdout);
1500                 putchar(line_termination);
1501         }
1502 }
1503
1504 static void stat_patch_list(struct patch *patch)
1505 {
1506         int files, adds, dels;
1507
1508         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
1509                 files++;
1510                 adds += patch->lines_added;
1511                 dels += patch->lines_deleted;
1512                 show_stats(patch);
1513         }
1514
1515         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
1516 }
1517
1518 static void numstat_patch_list(struct patch *patch)
1519 {
1520         for ( ; patch; patch = patch->next) {
1521                 const char *name;
1522                 name = patch->old_name ? patch->old_name : patch->new_name;
1523                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
1524                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
1525                         quote_c_style(name, NULL, stdout, 0);
1526                 else
1527                         fputs(name, stdout);
1528                 putchar('\n');
1529         }
1530 }
1531
1532 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
1533 {
1534         if (mode)
1535                 printf(" %s mode %06o %s\n", newdelete, mode, name);
1536         else
1537                 printf(" %s %s\n", newdelete, name);
1538 }
1539
1540 static void show_mode_change(struct patch *p, int show_name)
1541 {
1542         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
1543                 if (show_name)
1544                         printf(" mode change %06o => %06o %s\n",
1545                                p->old_mode, p->new_mode, p->new_name);
1546                 else
1547                         printf(" mode change %06o => %06o\n",
1548                                p->old_mode, p->new_mode);
1549         }
1550 }
1551
1552 static void show_rename_copy(struct patch *p)
1553 {
1554         const char *renamecopy = p->is_rename ? "rename" : "copy";
1555         const char *old, *new;
1556
1557         /* Find common prefix */
1558         old = p->old_name;
1559         new = p->new_name;
1560         while (1) {
1561                 const char *slash_old, *slash_new;
1562                 slash_old = strchr(old, '/');
1563                 slash_new = strchr(new, '/');
1564                 if (!slash_old ||
1565                     !slash_new ||
1566                     slash_old - old != slash_new - new ||
1567                     memcmp(old, new, slash_new - new))
1568                         break;
1569                 old = slash_old + 1;
1570                 new = slash_new + 1;
1571         }
1572         /* p->old_name thru old is the common prefix, and old and new
1573          * through the end of names are renames
1574          */
1575         if (old != p->old_name)
1576                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
1577                        (int)(old - p->old_name), p->old_name,
1578                        old, new, p->score);
1579         else
1580                 printf(" %s %s => %s (%d%%)\n", renamecopy,
1581                        p->old_name, p->new_name, p->score);
1582         show_mode_change(p, 0);
1583 }
1584
1585 static void summary_patch_list(struct patch *patch)
1586 {
1587         struct patch *p;
1588
1589         for (p = patch; p; p = p->next) {
1590                 if (p->is_new)
1591                         show_file_mode_name("create", p->new_mode, p->new_name);
1592                 else if (p->is_delete)
1593                         show_file_mode_name("delete", p->old_mode, p->old_name);
1594                 else {
1595                         if (p->is_rename || p->is_copy)
1596                                 show_rename_copy(p);
1597                         else {
1598                                 if (p->score) {
1599                                         printf(" rewrite %s (%d%%)\n",
1600                                                p->new_name, p->score);
1601                                         show_mode_change(p, 0);
1602                                 }
1603                                 else
1604                                         show_mode_change(p, 1);
1605                         }
1606                 }
1607         }
1608 }
1609
1610 static void patch_stats(struct patch *patch)
1611 {
1612         int lines = patch->lines_added + patch->lines_deleted;
1613
1614         if (lines > max_change)
1615                 max_change = lines;
1616         if (patch->old_name) {
1617                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
1618                 if (!len)
1619                         len = strlen(patch->old_name);
1620                 if (len > max_len)
1621                         max_len = len;
1622         }
1623         if (patch->new_name) {
1624                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
1625                 if (!len)
1626                         len = strlen(patch->new_name);
1627                 if (len > max_len)
1628                         max_len = len;
1629         }
1630 }
1631
1632 static void remove_file(struct patch *patch)
1633 {
1634         if (write_index) {
1635                 if (remove_file_from_cache(patch->old_name) < 0)
1636                         die("unable to remove %s from index", patch->old_name);
1637         }
1638         unlink(patch->old_name);
1639 }
1640
1641 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
1642 {
1643         struct stat st;
1644         struct cache_entry *ce;
1645         int namelen = strlen(path);
1646         unsigned ce_size = cache_entry_size(namelen);
1647
1648         if (!write_index)
1649                 return;
1650
1651         ce = xmalloc(ce_size);
1652         memset(ce, 0, ce_size);
1653         memcpy(ce->name, path, namelen);
1654         ce->ce_mode = create_ce_mode(mode);
1655         ce->ce_flags = htons(namelen);
1656         if (lstat(path, &st) < 0)
1657                 die("unable to stat newly created file %s", path);
1658         fill_stat_cache_info(ce, &st);
1659         if (write_sha1_file(buf, size, "blob", ce->sha1) < 0)
1660                 die("unable to create backing store for newly created file %s", path);
1661         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
1662                 die("unable to add cache entry for %s", path);
1663 }
1664
1665 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
1666 {
1667         int fd;
1668
1669         if (S_ISLNK(mode))
1670                 return symlink(buf, path);
1671         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
1672         if (fd < 0)
1673                 return -1;
1674         while (size) {
1675                 int written = xwrite(fd, buf, size);
1676                 if (written < 0)
1677                         die("writing file %s: %s", path, strerror(errno));
1678                 if (!written)
1679                         die("out of space writing file %s", path);
1680                 buf += written;
1681                 size -= written;
1682         }
1683         if (close(fd) < 0)
1684                 die("closing file %s: %s", path, strerror(errno));
1685         return 0;
1686 }
1687
1688 /*
1689  * We optimistically assume that the directories exist,
1690  * which is true 99% of the time anyway. If they don't,
1691  * we create them and try again.
1692  */
1693 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
1694 {
1695         if (!try_create_file(path, mode, buf, size))
1696                 return;
1697
1698         if (errno == ENOENT) {
1699                 if (safe_create_leading_directories(path))
1700                         return;
1701                 if (!try_create_file(path, mode, buf, size))
1702                         return;
1703         }
1704
1705         if (errno == EEXIST) {
1706                 unsigned int nr = getpid();
1707
1708                 for (;;) {
1709                         const char *newpath;
1710                         newpath = mkpath("%s~%u", path, nr);
1711                         if (!try_create_file(newpath, mode, buf, size)) {
1712                                 if (!rename(newpath, path))
1713                                         return;
1714                                 unlink(newpath);
1715                                 break;
1716                         }
1717                         if (errno != EEXIST)
1718                                 break;
1719                         ++nr;
1720                 }
1721         }
1722         die("unable to write file %s mode %o", path, mode);
1723 }
1724
1725 static void create_file(struct patch *patch)
1726 {
1727         char *path = patch->new_name;
1728         unsigned mode = patch->new_mode;
1729         unsigned long size = patch->resultsize;
1730         char *buf = patch->result;
1731
1732         if (!mode)
1733                 mode = S_IFREG | 0644;
1734         create_one_file(path, mode, buf, size); 
1735         add_index_file(path, mode, buf, size);
1736 }
1737
1738 static void write_out_one_result(struct patch *patch)
1739 {
1740         if (patch->is_delete > 0) {
1741                 remove_file(patch);
1742                 return;
1743         }
1744         if (patch->is_new > 0 || patch->is_copy) {
1745                 create_file(patch);
1746                 return;
1747         }
1748         /*
1749          * Rename or modification boils down to the same
1750          * thing: remove the old, write the new
1751          */
1752         remove_file(patch);
1753         create_file(patch);
1754 }
1755
1756 static void write_out_results(struct patch *list, int skipped_patch)
1757 {
1758         if (!list && !skipped_patch)
1759                 die("No changes");
1760
1761         while (list) {
1762                 write_out_one_result(list);
1763                 list = list->next;
1764         }
1765 }
1766
1767 static struct cache_file cache_file;
1768
1769 static struct excludes {
1770         struct excludes *next;
1771         const char *path;
1772 } *excludes;
1773
1774 static int use_patch(struct patch *p)
1775 {
1776         const char *pathname = p->new_name ? p->new_name : p->old_name;
1777         struct excludes *x = excludes;
1778         while (x) {
1779                 if (fnmatch(x->path, pathname, 0) == 0)
1780                         return 0;
1781                 x = x->next;
1782         }
1783         if (0 < prefix_length) {
1784                 int pathlen = strlen(pathname);
1785                 if (pathlen <= prefix_length ||
1786                     memcmp(prefix, pathname, prefix_length))
1787                         return 0;
1788         }
1789         return 1;
1790 }
1791
1792 static int apply_patch(int fd, const char *filename)
1793 {
1794         int newfd;
1795         unsigned long offset, size;
1796         char *buffer = read_patch_file(fd, &size);
1797         struct patch *list = NULL, **listp = &list;
1798         int skipped_patch = 0;
1799
1800         patch_input_file = filename;
1801         if (!buffer)
1802                 return -1;
1803         offset = 0;
1804         while (size > 0) {
1805                 struct patch *patch;
1806                 int nr;
1807
1808                 patch = xmalloc(sizeof(*patch));
1809                 memset(patch, 0, sizeof(*patch));
1810                 nr = parse_chunk(buffer + offset, size, patch);
1811                 if (nr < 0)
1812                         break;
1813                 if (use_patch(patch)) {
1814                         patch_stats(patch);
1815                         *listp = patch;
1816                         listp = &patch->next;
1817                 } else {
1818                         /* perhaps free it a bit better? */
1819                         free(patch);
1820                         skipped_patch++;
1821                 }
1822                 offset += nr;
1823                 size -= nr;
1824         }
1825
1826         newfd = -1;
1827         if (whitespace_error && (new_whitespace == error_on_whitespace))
1828                 apply = 0;
1829
1830         write_index = check_index && apply;
1831         if (write_index)
1832                 newfd = hold_index_file_for_update(&cache_file, get_index_file());
1833         if (check_index) {
1834                 if (read_cache() < 0)
1835                         die("unable to read index file");
1836         }
1837
1838         if ((check || apply) && check_patch_list(list) < 0)
1839                 exit(1);
1840
1841         if (apply)
1842                 write_out_results(list, skipped_patch);
1843
1844         if (write_index) {
1845                 if (write_cache(newfd, active_cache, active_nr) ||
1846                     commit_index_file(&cache_file))
1847                         die("Unable to write new cachefile");
1848         }
1849
1850         if (show_index_info)
1851                 show_index_list(list);
1852
1853         if (diffstat)
1854                 stat_patch_list(list);
1855
1856         if (numstat)
1857                 numstat_patch_list(list);
1858
1859         if (summary)
1860                 summary_patch_list(list);
1861
1862         free(buffer);
1863         return 0;
1864 }
1865
1866 static int git_apply_config(const char *var, const char *value)
1867 {
1868         if (!strcmp(var, "apply.whitespace")) {
1869                 apply_default_whitespace = strdup(value);
1870                 return 0;
1871         }
1872         return git_default_config(var, value);
1873 }
1874
1875
1876 int main(int argc, char **argv)
1877 {
1878         int i;
1879         int read_stdin = 1;
1880         const char *whitespace_option = NULL;
1881
1882         for (i = 1; i < argc; i++) {
1883                 const char *arg = argv[i];
1884                 int fd;
1885
1886                 if (!strcmp(arg, "-")) {
1887                         apply_patch(0, "<stdin>");
1888                         read_stdin = 0;
1889                         continue;
1890                 }
1891                 if (!strncmp(arg, "--exclude=", 10)) {
1892                         struct excludes *x = xmalloc(sizeof(*x));
1893                         x->path = arg + 10;
1894                         x->next = excludes;
1895                         excludes = x;
1896                         continue;
1897                 }
1898                 if (!strncmp(arg, "-p", 2)) {
1899                         p_value = atoi(arg + 2);
1900                         continue;
1901                 }
1902                 if (!strcmp(arg, "--no-add")) {
1903                         no_add = 1;
1904                         continue;
1905                 }
1906                 if (!strcmp(arg, "--stat")) {
1907                         apply = 0;
1908                         diffstat = 1;
1909                         continue;
1910                 }
1911                 if (!strcmp(arg, "--allow-binary-replacement")) {
1912                         allow_binary_replacement = 1;
1913                         continue;
1914                 }
1915                 if (!strcmp(arg, "--numstat")) {
1916                         apply = 0;
1917                         numstat = 1;
1918                         continue;
1919                 }
1920                 if (!strcmp(arg, "--summary")) {
1921                         apply = 0;
1922                         summary = 1;
1923                         continue;
1924                 }
1925                 if (!strcmp(arg, "--check")) {
1926                         apply = 0;
1927                         check = 1;
1928                         continue;
1929                 }
1930                 if (!strcmp(arg, "--index")) {
1931                         check_index = 1;
1932                         continue;
1933                 }
1934                 if (!strcmp(arg, "--apply")) {
1935                         apply = 1;
1936                         continue;
1937                 }
1938                 if (!strcmp(arg, "--index-info")) {
1939                         apply = 0;
1940                         show_index_info = 1;
1941                         continue;
1942                 }
1943                 if (!strcmp(arg, "-z")) {
1944                         line_termination = 0;
1945                         continue;
1946                 }
1947                 if (!strncmp(arg, "--whitespace=", 13)) {
1948                         whitespace_option = arg + 13;
1949                         parse_whitespace_option(arg + 13);
1950                         continue;
1951                 }
1952
1953                 if (check_index && prefix_length < 0) {
1954                         prefix = setup_git_directory();
1955                         prefix_length = prefix ? strlen(prefix) : 0;
1956                         git_config(git_apply_config);
1957                         if (!whitespace_option && apply_default_whitespace)
1958                                 parse_whitespace_option(apply_default_whitespace);
1959                 }
1960                 if (0 < prefix_length)
1961                         arg = prefix_filename(prefix, prefix_length, arg);
1962
1963                 fd = open(arg, O_RDONLY);
1964                 if (fd < 0)
1965                         usage(apply_usage);
1966                 read_stdin = 0;
1967                 set_default_whitespace_mode(whitespace_option);
1968                 apply_patch(fd, arg);
1969                 close(fd);
1970         }
1971         set_default_whitespace_mode(whitespace_option);
1972         if (read_stdin)
1973                 apply_patch(0, "<stdin>");
1974         if (whitespace_error) {
1975                 if (squelch_whitespace_errors &&
1976                     squelch_whitespace_errors < whitespace_error) {
1977                         int squelched =
1978                                 whitespace_error - squelch_whitespace_errors;
1979                         fprintf(stderr, "warning: squelched %d whitespace error%s\n",
1980                                 squelched,
1981                                 squelched == 1 ? "" : "s");
1982                 }
1983                 if (new_whitespace == error_on_whitespace)
1984                         die("%d line%s add%s trailing whitespaces.",
1985                             whitespace_error,
1986                             whitespace_error == 1 ? "" : "s",
1987                             whitespace_error == 1 ? "s" : "");
1988                 if (applied_after_stripping)
1989                         fprintf(stderr, "warning: %d line%s applied after"
1990                                 " stripping trailing whitespaces.\n",
1991                                 applied_after_stripping,
1992                                 applied_after_stripping == 1 ? "" : "s");
1993                 else if (whitespace_error)
1994                         fprintf(stderr, "warning: %d line%s add%s trailing"
1995                                 " whitespaces.\n",
1996                                 whitespace_error,
1997                                 whitespace_error == 1 ? "" : "s",
1998                                 whitespace_error == 1 ? "s" : "");
1999         }
2000         return 0;
2001 }