Merge branch 'jc/gitpm'
[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 <fnmatch.h>
10 #include "cache.h"
11 #include "cache-tree.h"
12 #include "quote.h"
13 #include "blob.h"
14 #include "delta.h"
15 #include "builtin.h"
16
17 /*
18  *  --check turns on checking that the working tree matches the
19  *    files that are being modified, but doesn't apply the patch
20  *  --stat does just a diffstat, and doesn't actually apply
21  *  --numstat does numeric diffstat, and doesn't actually apply
22  *  --index-info shows the old and new index info for paths if available.
23  *  --index updates the cache as well.
24  *  --cached updates only the cache without ever touching the working tree.
25  */
26 static const char *prefix;
27 static int prefix_length = -1;
28 static int newfd = -1;
29
30 static int unidiff_zero;
31 static int p_value = 1;
32 static int check_index;
33 static int write_index;
34 static int cached;
35 static int diffstat;
36 static int numstat;
37 static int summary;
38 static int check;
39 static int apply = 1;
40 static int apply_in_reverse;
41 static int apply_with_reject;
42 static int apply_verbosely;
43 static int no_add;
44 static int show_index_info;
45 static int line_termination = '\n';
46 static unsigned long p_context = -1;
47 static const char apply_usage[] =
48 "git-apply [--stat] [--numstat] [--summary] [--check] [--index] [--cached] [--apply] [--no-add] [--index-info] [--allow-binary-replacement] [--reverse] [--reject] [--verbose] [-z] [-pNUM] [-CNUM] [--whitespace=<nowarn|warn|error|error-all|strip>] <patch>...";
49
50 static enum whitespace_eol {
51         nowarn_whitespace,
52         warn_on_whitespace,
53         error_on_whitespace,
54         strip_whitespace,
55 } new_whitespace = warn_on_whitespace;
56 static int whitespace_error;
57 static int squelch_whitespace_errors = 5;
58 static int applied_after_stripping;
59 static const char *patch_input_file;
60
61 static void parse_whitespace_option(const char *option)
62 {
63         if (!option) {
64                 new_whitespace = warn_on_whitespace;
65                 return;
66         }
67         if (!strcmp(option, "warn")) {
68                 new_whitespace = warn_on_whitespace;
69                 return;
70         }
71         if (!strcmp(option, "nowarn")) {
72                 new_whitespace = nowarn_whitespace;
73                 return;
74         }
75         if (!strcmp(option, "error")) {
76                 new_whitespace = error_on_whitespace;
77                 return;
78         }
79         if (!strcmp(option, "error-all")) {
80                 new_whitespace = error_on_whitespace;
81                 squelch_whitespace_errors = 0;
82                 return;
83         }
84         if (!strcmp(option, "strip")) {
85                 new_whitespace = strip_whitespace;
86                 return;
87         }
88         die("unrecognized whitespace option '%s'", option);
89 }
90
91 static void set_default_whitespace_mode(const char *whitespace_option)
92 {
93         if (!whitespace_option && !apply_default_whitespace) {
94                 new_whitespace = (apply
95                                   ? warn_on_whitespace
96                                   : nowarn_whitespace);
97         }
98 }
99
100 /*
101  * For "diff-stat" like behaviour, we keep track of the biggest change
102  * we've seen, and the longest filename. That allows us to do simple
103  * scaling.
104  */
105 static int max_change, max_len;
106
107 /*
108  * Various "current state", notably line numbers and what
109  * file (and how) we're patching right now.. The "is_xxxx"
110  * things are flags, where -1 means "don't know yet".
111  */
112 static int linenr = 1;
113
114 /*
115  * This represents one "hunk" from a patch, starting with
116  * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
117  * patch text is pointed at by patch, and its byte length
118  * is stored in size.  leading and trailing are the number
119  * of context lines.
120  */
121 struct fragment {
122         unsigned long leading, trailing;
123         unsigned long oldpos, oldlines;
124         unsigned long newpos, newlines;
125         const char *patch;
126         int size;
127         int rejected;
128         struct fragment *next;
129 };
130
131 /*
132  * When dealing with a binary patch, we reuse "leading" field
133  * to store the type of the binary hunk, either deflated "delta"
134  * or deflated "literal".
135  */
136 #define binary_patch_method leading
137 #define BINARY_DELTA_DEFLATED   1
138 #define BINARY_LITERAL_DEFLATED 2
139
140 struct patch {
141         char *new_name, *old_name, *def_name;
142         unsigned int old_mode, new_mode;
143         int is_rename, is_copy, is_new, is_delete, is_binary;
144         int rejected;
145         unsigned long deflate_origlen;
146         int lines_added, lines_deleted;
147         int score;
148         int inaccurate_eof:1;
149         struct fragment *fragments;
150         char *result;
151         unsigned long resultsize;
152         char old_sha1_prefix[41];
153         char new_sha1_prefix[41];
154         struct patch *next;
155 };
156
157 static void say_patch_name(FILE *output, const char *pre, struct patch *patch, const char *post)
158 {
159         fputs(pre, output);
160         if (patch->old_name && patch->new_name &&
161             strcmp(patch->old_name, patch->new_name)) {
162                 write_name_quoted(NULL, 0, patch->old_name, 1, output);
163                 fputs(" => ", output);
164                 write_name_quoted(NULL, 0, patch->new_name, 1, output);
165         }
166         else {
167                 const char *n = patch->new_name;
168                 if (!n)
169                         n = patch->old_name;
170                 write_name_quoted(NULL, 0, n, 1, output);
171         }
172         fputs(post, output);
173 }
174
175 #define CHUNKSIZE (8192)
176 #define SLOP (16)
177
178 static void *read_patch_file(int fd, unsigned long *sizep)
179 {
180         unsigned long size = 0, alloc = CHUNKSIZE;
181         void *buffer = xmalloc(alloc);
182
183         for (;;) {
184                 int nr = alloc - size;
185                 if (nr < 1024) {
186                         alloc += CHUNKSIZE;
187                         buffer = xrealloc(buffer, alloc);
188                         nr = alloc - size;
189                 }
190                 nr = xread(fd, (char *) buffer + size, nr);
191                 if (!nr)
192                         break;
193                 if (nr < 0)
194                         die("git-apply: read returned %s", strerror(errno));
195                 size += nr;
196         }
197         *sizep = size;
198
199         /*
200          * Make sure that we have some slop in the buffer
201          * so that we can do speculative "memcmp" etc, and
202          * see to it that it is NUL-filled.
203          */
204         if (alloc < size + SLOP)
205                 buffer = xrealloc(buffer, size + SLOP);
206         memset((char *) buffer + size, 0, SLOP);
207         return buffer;
208 }
209
210 static unsigned long linelen(const char *buffer, unsigned long size)
211 {
212         unsigned long len = 0;
213         while (size--) {
214                 len++;
215                 if (*buffer++ == '\n')
216                         break;
217         }
218         return len;
219 }
220
221 static int is_dev_null(const char *str)
222 {
223         return !memcmp("/dev/null", str, 9) && isspace(str[9]);
224 }
225
226 #define TERM_SPACE      1
227 #define TERM_TAB        2
228
229 static int name_terminate(const char *name, int namelen, int c, int terminate)
230 {
231         if (c == ' ' && !(terminate & TERM_SPACE))
232                 return 0;
233         if (c == '\t' && !(terminate & TERM_TAB))
234                 return 0;
235
236         return 1;
237 }
238
239 static char * find_name(const char *line, char *def, int p_value, int terminate)
240 {
241         int len;
242         const char *start = line;
243         char *name;
244
245         if (*line == '"') {
246                 /* Proposed "new-style" GNU patch/diff format; see
247                  * http://marc.theaimsgroup.com/?l=git&m=112927316408690&w=2
248                  */
249                 name = unquote_c_style(line, NULL);
250                 if (name) {
251                         char *cp = name;
252                         while (p_value) {
253                                 cp = strchr(name, '/');
254                                 if (!cp)
255                                         break;
256                                 cp++;
257                                 p_value--;
258                         }
259                         if (cp) {
260                                 /* name can later be freed, so we need
261                                  * to memmove, not just return cp
262                                  */
263                                 memmove(name, cp, strlen(cp) + 1);
264                                 free(def);
265                                 return name;
266                         }
267                         else {
268                                 free(name);
269                                 name = NULL;
270                         }
271                 }
272         }
273
274         for (;;) {
275                 char c = *line;
276
277                 if (isspace(c)) {
278                         if (c == '\n')
279                                 break;
280                         if (name_terminate(start, line-start, c, terminate))
281                                 break;
282                 }
283                 line++;
284                 if (c == '/' && !--p_value)
285                         start = line;
286         }
287         if (!start)
288                 return def;
289         len = line - start;
290         if (!len)
291                 return def;
292
293         /*
294          * Generally we prefer the shorter name, especially
295          * if the other one is just a variation of that with
296          * something else tacked on to the end (ie "file.orig"
297          * or "file~").
298          */
299         if (def) {
300                 int deflen = strlen(def);
301                 if (deflen < len && !strncmp(start, def, deflen))
302                         return def;
303         }
304
305         name = xmalloc(len + 1);
306         memcpy(name, start, len);
307         name[len] = 0;
308         free(def);
309         return name;
310 }
311
312 /*
313  * Get the name etc info from the --/+++ lines of a traditional patch header
314  *
315  * NOTE! This hardcodes "-p1" behaviour in filename detection.
316  *
317  * FIXME! The end-of-filename heuristics are kind of screwy. For existing
318  * files, we can happily check the index for a match, but for creating a
319  * new file we should try to match whatever "patch" does. I have no idea.
320  */
321 static void parse_traditional_patch(const char *first, const char *second, struct patch *patch)
322 {
323         char *name;
324
325         first += 4;     /* skip "--- " */
326         second += 4;    /* skip "+++ " */
327         if (is_dev_null(first)) {
328                 patch->is_new = 1;
329                 patch->is_delete = 0;
330                 name = find_name(second, NULL, p_value, TERM_SPACE | TERM_TAB);
331                 patch->new_name = name;
332         } else if (is_dev_null(second)) {
333                 patch->is_new = 0;
334                 patch->is_delete = 1;
335                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
336                 patch->old_name = name;
337         } else {
338                 name = find_name(first, NULL, p_value, TERM_SPACE | TERM_TAB);
339                 name = find_name(second, name, p_value, TERM_SPACE | TERM_TAB);
340                 patch->old_name = patch->new_name = name;
341         }
342         if (!name)
343                 die("unable to find filename in patch at line %d", linenr);
344 }
345
346 static int gitdiff_hdrend(const char *line, struct patch *patch)
347 {
348         return -1;
349 }
350
351 /*
352  * We're anal about diff header consistency, to make
353  * sure that we don't end up having strange ambiguous
354  * patches floating around.
355  *
356  * As a result, gitdiff_{old|new}name() will check
357  * their names against any previous information, just
358  * to make sure..
359  */
360 static char *gitdiff_verify_name(const char *line, int isnull, char *orig_name, const char *oldnew)
361 {
362         if (!orig_name && !isnull)
363                 return find_name(line, NULL, 1, 0);
364
365         if (orig_name) {
366                 int len;
367                 const char *name;
368                 char *another;
369                 name = orig_name;
370                 len = strlen(name);
371                 if (isnull)
372                         die("git-apply: bad git-diff - expected /dev/null, got %s on line %d", name, linenr);
373                 another = find_name(line, NULL, 1, 0);
374                 if (!another || memcmp(another, name, len))
375                         die("git-apply: bad git-diff - inconsistent %s filename on line %d", oldnew, linenr);
376                 free(another);
377                 return orig_name;
378         }
379         else {
380                 /* expect "/dev/null" */
381                 if (memcmp("/dev/null", line, 9) || line[9] != '\n')
382                         die("git-apply: bad git-diff - expected /dev/null on line %d", linenr);
383                 return NULL;
384         }
385 }
386
387 static int gitdiff_oldname(const char *line, struct patch *patch)
388 {
389         patch->old_name = gitdiff_verify_name(line, patch->is_new, patch->old_name, "old");
390         return 0;
391 }
392
393 static int gitdiff_newname(const char *line, struct patch *patch)
394 {
395         patch->new_name = gitdiff_verify_name(line, patch->is_delete, patch->new_name, "new");
396         return 0;
397 }
398
399 static int gitdiff_oldmode(const char *line, struct patch *patch)
400 {
401         patch->old_mode = strtoul(line, NULL, 8);
402         return 0;
403 }
404
405 static int gitdiff_newmode(const char *line, struct patch *patch)
406 {
407         patch->new_mode = strtoul(line, NULL, 8);
408         return 0;
409 }
410
411 static int gitdiff_delete(const char *line, struct patch *patch)
412 {
413         patch->is_delete = 1;
414         patch->old_name = patch->def_name;
415         return gitdiff_oldmode(line, patch);
416 }
417
418 static int gitdiff_newfile(const char *line, struct patch *patch)
419 {
420         patch->is_new = 1;
421         patch->new_name = patch->def_name;
422         return gitdiff_newmode(line, patch);
423 }
424
425 static int gitdiff_copysrc(const char *line, struct patch *patch)
426 {
427         patch->is_copy = 1;
428         patch->old_name = find_name(line, NULL, 0, 0);
429         return 0;
430 }
431
432 static int gitdiff_copydst(const char *line, struct patch *patch)
433 {
434         patch->is_copy = 1;
435         patch->new_name = find_name(line, NULL, 0, 0);
436         return 0;
437 }
438
439 static int gitdiff_renamesrc(const char *line, struct patch *patch)
440 {
441         patch->is_rename = 1;
442         patch->old_name = find_name(line, NULL, 0, 0);
443         return 0;
444 }
445
446 static int gitdiff_renamedst(const char *line, struct patch *patch)
447 {
448         patch->is_rename = 1;
449         patch->new_name = find_name(line, NULL, 0, 0);
450         return 0;
451 }
452
453 static int gitdiff_similarity(const char *line, struct patch *patch)
454 {
455         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
456                 patch->score = 0;
457         return 0;
458 }
459
460 static int gitdiff_dissimilarity(const char *line, struct patch *patch)
461 {
462         if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
463                 patch->score = 0;
464         return 0;
465 }
466
467 static int gitdiff_index(const char *line, struct patch *patch)
468 {
469         /* index line is N hexadecimal, "..", N hexadecimal,
470          * and optional space with octal mode.
471          */
472         const char *ptr, *eol;
473         int len;
474
475         ptr = strchr(line, '.');
476         if (!ptr || ptr[1] != '.' || 40 < ptr - line)
477                 return 0;
478         len = ptr - line;
479         memcpy(patch->old_sha1_prefix, line, len);
480         patch->old_sha1_prefix[len] = 0;
481
482         line = ptr + 2;
483         ptr = strchr(line, ' ');
484         eol = strchr(line, '\n');
485
486         if (!ptr || eol < ptr)
487                 ptr = eol;
488         len = ptr - line;
489
490         if (40 < len)
491                 return 0;
492         memcpy(patch->new_sha1_prefix, line, len);
493         patch->new_sha1_prefix[len] = 0;
494         if (*ptr == ' ')
495                 patch->new_mode = patch->old_mode = strtoul(ptr+1, NULL, 8);
496         return 0;
497 }
498
499 /*
500  * This is normal for a diff that doesn't change anything: we'll fall through
501  * into the next diff. Tell the parser to break out.
502  */
503 static int gitdiff_unrecognized(const char *line, struct patch *patch)
504 {
505         return -1;
506 }
507
508 static const char *stop_at_slash(const char *line, int llen)
509 {
510         int i;
511
512         for (i = 0; i < llen; i++) {
513                 int ch = line[i];
514                 if (ch == '/')
515                         return line + i;
516         }
517         return NULL;
518 }
519
520 /* This is to extract the same name that appears on "diff --git"
521  * line.  We do not find and return anything if it is a rename
522  * patch, and it is OK because we will find the name elsewhere.
523  * We need to reliably find name only when it is mode-change only,
524  * creation or deletion of an empty file.  In any of these cases,
525  * both sides are the same name under a/ and b/ respectively.
526  */
527 static char *git_header_name(char *line, int llen)
528 {
529         int len;
530         const char *name;
531         const char *second = NULL;
532
533         line += strlen("diff --git ");
534         llen -= strlen("diff --git ");
535
536         if (*line == '"') {
537                 const char *cp;
538                 char *first = unquote_c_style(line, &second);
539                 if (!first)
540                         return NULL;
541
542                 /* advance to the first slash */
543                 cp = stop_at_slash(first, strlen(first));
544                 if (!cp || cp == first) {
545                         /* we do not accept absolute paths */
546                 free_first_and_fail:
547                         free(first);
548                         return NULL;
549                 }
550                 len = strlen(cp+1);
551                 memmove(first, cp+1, len+1); /* including NUL */
552
553                 /* second points at one past closing dq of name.
554                  * find the second name.
555                  */
556                 while ((second < line + llen) && isspace(*second))
557                         second++;
558
559                 if (line + llen <= second)
560                         goto free_first_and_fail;
561                 if (*second == '"') {
562                         char *sp = unquote_c_style(second, NULL);
563                         if (!sp)
564                                 goto free_first_and_fail;
565                         cp = stop_at_slash(sp, strlen(sp));
566                         if (!cp || cp == sp) {
567                         free_both_and_fail:
568                                 free(sp);
569                                 goto free_first_and_fail;
570                         }
571                         /* They must match, otherwise ignore */
572                         if (strcmp(cp+1, first))
573                                 goto free_both_and_fail;
574                         free(sp);
575                         return first;
576                 }
577
578                 /* unquoted second */
579                 cp = stop_at_slash(second, line + llen - second);
580                 if (!cp || cp == second)
581                         goto free_first_and_fail;
582                 cp++;
583                 if (line + llen - cp != len + 1 ||
584                     memcmp(first, cp, len))
585                         goto free_first_and_fail;
586                 return first;
587         }
588
589         /* unquoted first name */
590         name = stop_at_slash(line, llen);
591         if (!name || name == line)
592                 return NULL;
593
594         name++;
595
596         /* since the first name is unquoted, a dq if exists must be
597          * the beginning of the second name.
598          */
599         for (second = name; second < line + llen; second++) {
600                 if (*second == '"') {
601                         const char *cp = second;
602                         const char *np;
603                         char *sp = unquote_c_style(second, NULL);
604
605                         if (!sp)
606                                 return NULL;
607                         np = stop_at_slash(sp, strlen(sp));
608                         if (!np || np == sp) {
609                         free_second_and_fail:
610                                 free(sp);
611                                 return NULL;
612                         }
613                         np++;
614                         len = strlen(np);
615                         if (len < cp - name &&
616                             !strncmp(np, name, len) &&
617                             isspace(name[len])) {
618                                 /* Good */
619                                 memmove(sp, np, len + 1);
620                                 return sp;
621                         }
622                         goto free_second_and_fail;
623                 }
624         }
625
626         /*
627          * Accept a name only if it shows up twice, exactly the same
628          * form.
629          */
630         for (len = 0 ; ; len++) {
631                 switch (name[len]) {
632                 default:
633                         continue;
634                 case '\n':
635                         return NULL;
636                 case '\t': case ' ':
637                         second = name+len;
638                         for (;;) {
639                                 char c = *second++;
640                                 if (c == '\n')
641                                         return NULL;
642                                 if (c == '/')
643                                         break;
644                         }
645                         if (second[len] == '\n' && !memcmp(name, second, len)) {
646                                 char *ret = xmalloc(len + 1);
647                                 memcpy(ret, name, len);
648                                 ret[len] = 0;
649                                 return ret;
650                         }
651                 }
652         }
653         return NULL;
654 }
655
656 /* Verify that we recognize the lines following a git header */
657 static int parse_git_header(char *line, int len, unsigned int size, struct patch *patch)
658 {
659         unsigned long offset;
660
661         /* A git diff has explicit new/delete information, so we don't guess */
662         patch->is_new = 0;
663         patch->is_delete = 0;
664
665         /*
666          * Some things may not have the old name in the
667          * rest of the headers anywhere (pure mode changes,
668          * or removing or adding empty files), so we get
669          * the default name from the header.
670          */
671         patch->def_name = git_header_name(line, len);
672
673         line += len;
674         size -= len;
675         linenr++;
676         for (offset = len ; size > 0 ; offset += len, size -= len, line += len, linenr++) {
677                 static const struct opentry {
678                         const char *str;
679                         int (*fn)(const char *, struct patch *);
680                 } optable[] = {
681                         { "@@ -", gitdiff_hdrend },
682                         { "--- ", gitdiff_oldname },
683                         { "+++ ", gitdiff_newname },
684                         { "old mode ", gitdiff_oldmode },
685                         { "new mode ", gitdiff_newmode },
686                         { "deleted file mode ", gitdiff_delete },
687                         { "new file mode ", gitdiff_newfile },
688                         { "copy from ", gitdiff_copysrc },
689                         { "copy to ", gitdiff_copydst },
690                         { "rename old ", gitdiff_renamesrc },
691                         { "rename new ", gitdiff_renamedst },
692                         { "rename from ", gitdiff_renamesrc },
693                         { "rename to ", gitdiff_renamedst },
694                         { "similarity index ", gitdiff_similarity },
695                         { "dissimilarity index ", gitdiff_dissimilarity },
696                         { "index ", gitdiff_index },
697                         { "", gitdiff_unrecognized },
698                 };
699                 int i;
700
701                 len = linelen(line, size);
702                 if (!len || line[len-1] != '\n')
703                         break;
704                 for (i = 0; i < ARRAY_SIZE(optable); i++) {
705                         const struct opentry *p = optable + i;
706                         int oplen = strlen(p->str);
707                         if (len < oplen || memcmp(p->str, line, oplen))
708                                 continue;
709                         if (p->fn(line + oplen, patch) < 0)
710                                 return offset;
711                         break;
712                 }
713         }
714
715         return offset;
716 }
717
718 static int parse_num(const char *line, unsigned long *p)
719 {
720         char *ptr;
721
722         if (!isdigit(*line))
723                 return 0;
724         *p = strtoul(line, &ptr, 10);
725         return ptr - line;
726 }
727
728 static int parse_range(const char *line, int len, int offset, const char *expect,
729                         unsigned long *p1, unsigned long *p2)
730 {
731         int digits, ex;
732
733         if (offset < 0 || offset >= len)
734                 return -1;
735         line += offset;
736         len -= offset;
737
738         digits = parse_num(line, p1);
739         if (!digits)
740                 return -1;
741
742         offset += digits;
743         line += digits;
744         len -= digits;
745
746         *p2 = 1;
747         if (*line == ',') {
748                 digits = parse_num(line+1, p2);
749                 if (!digits)
750                         return -1;
751
752                 offset += digits+1;
753                 line += digits+1;
754                 len -= digits+1;
755         }
756
757         ex = strlen(expect);
758         if (ex > len)
759                 return -1;
760         if (memcmp(line, expect, ex))
761                 return -1;
762
763         return offset + ex;
764 }
765
766 /*
767  * Parse a unified diff fragment header of the
768  * form "@@ -a,b +c,d @@"
769  */
770 static int parse_fragment_header(char *line, int len, struct fragment *fragment)
771 {
772         int offset;
773
774         if (!len || line[len-1] != '\n')
775                 return -1;
776
777         /* Figure out the number of lines in a fragment */
778         offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
779         offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
780
781         return offset;
782 }
783
784 static int find_header(char *line, unsigned long size, int *hdrsize, struct patch *patch)
785 {
786         unsigned long offset, len;
787
788         patch->is_rename = patch->is_copy = 0;
789         patch->is_new = patch->is_delete = -1;
790         patch->old_mode = patch->new_mode = 0;
791         patch->old_name = patch->new_name = NULL;
792         for (offset = 0; size > 0; offset += len, size -= len, line += len, linenr++) {
793                 unsigned long nextlen;
794
795                 len = linelen(line, size);
796                 if (!len)
797                         break;
798
799                 /* Testing this early allows us to take a few shortcuts.. */
800                 if (len < 6)
801                         continue;
802
803                 /*
804                  * Make sure we don't find any unconnected patch fragments.
805                  * That's a sign that we didn't find a header, and that a
806                  * patch has become corrupted/broken up.
807                  */
808                 if (!memcmp("@@ -", line, 4)) {
809                         struct fragment dummy;
810                         if (parse_fragment_header(line, len, &dummy) < 0)
811                                 continue;
812                         error("patch fragment without header at line %d: %.*s", linenr, (int)len-1, line);
813                 }
814
815                 if (size < len + 6)
816                         break;
817
818                 /*
819                  * Git patch? It might not have a real patch, just a rename
820                  * or mode change, so we handle that specially
821                  */
822                 if (!memcmp("diff --git ", line, 11)) {
823                         int git_hdr_len = parse_git_header(line, len, size, patch);
824                         if (git_hdr_len <= len)
825                                 continue;
826                         if (!patch->old_name && !patch->new_name) {
827                                 if (!patch->def_name)
828                                         die("git diff header lacks filename information (line %d)", linenr);
829                                 patch->old_name = patch->new_name = patch->def_name;
830                         }
831                         *hdrsize = git_hdr_len;
832                         return offset;
833                 }
834
835                 /** --- followed by +++ ? */
836                 if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
837                         continue;
838
839                 /*
840                  * We only accept unified patches, so we want it to
841                  * at least have "@@ -a,b +c,d @@\n", which is 14 chars
842                  * minimum
843                  */
844                 nextlen = linelen(line + len, size - len);
845                 if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
846                         continue;
847
848                 /* Ok, we'll consider it a patch */
849                 parse_traditional_patch(line, line+len, patch);
850                 *hdrsize = len + nextlen;
851                 linenr += 2;
852                 return offset;
853         }
854         return -1;
855 }
856
857 static void check_whitespace(const char *line, int len)
858 {
859         const char *err = "Adds trailing whitespace";
860         int seen_space = 0;
861         int i;
862
863         /*
864          * We know len is at least two, since we have a '+' and we
865          * checked that the last character was a '\n' before calling
866          * this function.  That is, an addition of an empty line would
867          * check the '+' here.  Sneaky...
868          */
869         if (isspace(line[len-2]))
870                 goto error;
871
872         /*
873          * Make sure that there is no space followed by a tab in
874          * indentation.
875          */
876         err = "Space in indent is followed by a tab";
877         for (i = 1; i < len; i++) {
878                 if (line[i] == '\t') {
879                         if (seen_space)
880                                 goto error;
881                 }
882                 else if (line[i] == ' ')
883                         seen_space = 1;
884                 else
885                         break;
886         }
887         return;
888
889  error:
890         whitespace_error++;
891         if (squelch_whitespace_errors &&
892             squelch_whitespace_errors < whitespace_error)
893                 ;
894         else
895                 fprintf(stderr, "%s.\n%s:%d:%.*s\n",
896                         err, patch_input_file, linenr, len-2, line+1);
897 }
898
899
900 /*
901  * Parse a unified diff. Note that this really needs to parse each
902  * fragment separately, since the only way to know the difference
903  * between a "---" that is part of a patch, and a "---" that starts
904  * the next patch is to look at the line counts..
905  */
906 static int parse_fragment(char *line, unsigned long size, struct patch *patch, struct fragment *fragment)
907 {
908         int added, deleted;
909         int len = linelen(line, size), offset;
910         unsigned long oldlines, newlines;
911         unsigned long leading, trailing;
912
913         offset = parse_fragment_header(line, len, fragment);
914         if (offset < 0)
915                 return -1;
916         oldlines = fragment->oldlines;
917         newlines = fragment->newlines;
918         leading = 0;
919         trailing = 0;
920
921         /* Parse the thing.. */
922         line += len;
923         size -= len;
924         linenr++;
925         added = deleted = 0;
926         for (offset = len;
927              0 < size;
928              offset += len, size -= len, line += len, linenr++) {
929                 if (!oldlines && !newlines)
930                         break;
931                 len = linelen(line, size);
932                 if (!len || line[len-1] != '\n')
933                         return -1;
934                 switch (*line) {
935                 default:
936                         return -1;
937                 case ' ':
938                         oldlines--;
939                         newlines--;
940                         if (!deleted && !added)
941                                 leading++;
942                         trailing++;
943                         break;
944                 case '-':
945                         deleted++;
946                         oldlines--;
947                         trailing = 0;
948                         break;
949                 case '+':
950                         if (new_whitespace != nowarn_whitespace)
951                                 check_whitespace(line, len);
952                         added++;
953                         newlines--;
954                         trailing = 0;
955                         break;
956
957                 /* We allow "\ No newline at end of file". Depending
958                  * on locale settings when the patch was produced we
959                  * don't know what this line looks like. The only
960                  * thing we do know is that it begins with "\ ".
961                  * Checking for 12 is just for sanity check -- any
962                  * l10n of "\ No newline..." is at least that long.
963                  */
964                 case '\\':
965                         if (len < 12 || memcmp(line, "\\ ", 2))
966                                 return -1;
967                         break;
968                 }
969         }
970         if (oldlines || newlines)
971                 return -1;
972         fragment->leading = leading;
973         fragment->trailing = trailing;
974
975         /* If a fragment ends with an incomplete line, we failed to include
976          * it in the above loop because we hit oldlines == newlines == 0
977          * before seeing it.
978          */
979         if (12 < size && !memcmp(line, "\\ ", 2))
980                 offset += linelen(line, size);
981
982         patch->lines_added += added;
983         patch->lines_deleted += deleted;
984
985         if (0 < patch->is_new && oldlines)
986                 return error("new file depends on old contents");
987         if (0 < patch->is_delete && newlines)
988                 return error("deleted file still has contents");
989         return offset;
990 }
991
992 static int parse_single_patch(char *line, unsigned long size, struct patch *patch)
993 {
994         unsigned long offset = 0;
995         unsigned long oldlines = 0, newlines = 0, context = 0;
996         struct fragment **fragp = &patch->fragments;
997
998         while (size > 4 && !memcmp(line, "@@ -", 4)) {
999                 struct fragment *fragment;
1000                 int len;
1001
1002                 fragment = xcalloc(1, sizeof(*fragment));
1003                 len = parse_fragment(line, size, patch, fragment);
1004                 if (len <= 0)
1005                         die("corrupt patch at line %d", linenr);
1006                 fragment->patch = line;
1007                 fragment->size = len;
1008                 oldlines += fragment->oldlines;
1009                 newlines += fragment->newlines;
1010                 context += fragment->leading + fragment->trailing;
1011
1012                 *fragp = fragment;
1013                 fragp = &fragment->next;
1014
1015                 offset += len;
1016                 line += len;
1017                 size -= len;
1018         }
1019
1020         /*
1021          * If something was removed (i.e. we have old-lines) it cannot
1022          * be creation, and if something was added it cannot be
1023          * deletion.  However, the reverse is not true; --unified=0
1024          * patches that only add are not necessarily creation even
1025          * though they do not have any old lines, and ones that only
1026          * delete are not necessarily deletion.
1027          *
1028          * Unfortunately, a real creation/deletion patch do _not_ have
1029          * any context line by definition, so we cannot safely tell it
1030          * apart with --unified=0 insanity.  At least if the patch has
1031          * more than one hunk it is not creation or deletion.
1032          */
1033         if (patch->is_new < 0 &&
1034             (oldlines || (patch->fragments && patch->fragments->next)))
1035                 patch->is_new = 0;
1036         if (patch->is_delete < 0 &&
1037             (newlines || (patch->fragments && patch->fragments->next)))
1038                 patch->is_delete = 0;
1039         if (!unidiff_zero || context) {
1040                 /* If the user says the patch is not generated with
1041                  * --unified=0, or if we have seen context lines,
1042                  * then not having oldlines means the patch is creation,
1043                  * and not having newlines means the patch is deletion.
1044                  */
1045                 if (patch->is_new < 0 && !oldlines)
1046                         patch->is_new = 1;
1047                 if (patch->is_delete < 0 && !newlines)
1048                         patch->is_delete = 1;
1049         }
1050
1051         if (0 < patch->is_new && oldlines)
1052                 die("new file %s depends on old contents", patch->new_name);
1053         if (0 < patch->is_delete && newlines)
1054                 die("deleted file %s still has contents", patch->old_name);
1055         if (!patch->is_delete && !newlines && context)
1056                 fprintf(stderr, "** warning: file %s becomes empty but "
1057                         "is not deleted\n", patch->new_name);
1058
1059         return offset;
1060 }
1061
1062 static inline int metadata_changes(struct patch *patch)
1063 {
1064         return  patch->is_rename > 0 ||
1065                 patch->is_copy > 0 ||
1066                 patch->is_new > 0 ||
1067                 patch->is_delete ||
1068                 (patch->old_mode && patch->new_mode &&
1069                  patch->old_mode != patch->new_mode);
1070 }
1071
1072 static char *inflate_it(const void *data, unsigned long size,
1073                         unsigned long inflated_size)
1074 {
1075         z_stream stream;
1076         void *out;
1077         int st;
1078
1079         memset(&stream, 0, sizeof(stream));
1080
1081         stream.next_in = (unsigned char *)data;
1082         stream.avail_in = size;
1083         stream.next_out = out = xmalloc(inflated_size);
1084         stream.avail_out = inflated_size;
1085         inflateInit(&stream);
1086         st = inflate(&stream, Z_FINISH);
1087         if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
1088                 free(out);
1089                 return NULL;
1090         }
1091         return out;
1092 }
1093
1094 static struct fragment *parse_binary_hunk(char **buf_p,
1095                                           unsigned long *sz_p,
1096                                           int *status_p,
1097                                           int *used_p)
1098 {
1099         /* Expect a line that begins with binary patch method ("literal"
1100          * or "delta"), followed by the length of data before deflating.
1101          * a sequence of 'length-byte' followed by base-85 encoded data
1102          * should follow, terminated by a newline.
1103          *
1104          * Each 5-byte sequence of base-85 encodes up to 4 bytes,
1105          * and we would limit the patch line to 66 characters,
1106          * so one line can fit up to 13 groups that would decode
1107          * to 52 bytes max.  The length byte 'A'-'Z' corresponds
1108          * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
1109          */
1110         int llen, used;
1111         unsigned long size = *sz_p;
1112         char *buffer = *buf_p;
1113         int patch_method;
1114         unsigned long origlen;
1115         char *data = NULL;
1116         int hunk_size = 0;
1117         struct fragment *frag;
1118
1119         llen = linelen(buffer, size);
1120         used = llen;
1121
1122         *status_p = 0;
1123
1124         if (!strncmp(buffer, "delta ", 6)) {
1125                 patch_method = BINARY_DELTA_DEFLATED;
1126                 origlen = strtoul(buffer + 6, NULL, 10);
1127         }
1128         else if (!strncmp(buffer, "literal ", 8)) {
1129                 patch_method = BINARY_LITERAL_DEFLATED;
1130                 origlen = strtoul(buffer + 8, NULL, 10);
1131         }
1132         else
1133                 return NULL;
1134
1135         linenr++;
1136         buffer += llen;
1137         while (1) {
1138                 int byte_length, max_byte_length, newsize;
1139                 llen = linelen(buffer, size);
1140                 used += llen;
1141                 linenr++;
1142                 if (llen == 1) {
1143                         /* consume the blank line */
1144                         buffer++;
1145                         size--;
1146                         break;
1147                 }
1148                 /* Minimum line is "A00000\n" which is 7-byte long,
1149                  * and the line length must be multiple of 5 plus 2.
1150                  */
1151                 if ((llen < 7) || (llen-2) % 5)
1152                         goto corrupt;
1153                 max_byte_length = (llen - 2) / 5 * 4;
1154                 byte_length = *buffer;
1155                 if ('A' <= byte_length && byte_length <= 'Z')
1156                         byte_length = byte_length - 'A' + 1;
1157                 else if ('a' <= byte_length && byte_length <= 'z')
1158                         byte_length = byte_length - 'a' + 27;
1159                 else
1160                         goto corrupt;
1161                 /* if the input length was not multiple of 4, we would
1162                  * have filler at the end but the filler should never
1163                  * exceed 3 bytes
1164                  */
1165                 if (max_byte_length < byte_length ||
1166                     byte_length <= max_byte_length - 4)
1167                         goto corrupt;
1168                 newsize = hunk_size + byte_length;
1169                 data = xrealloc(data, newsize);
1170                 if (decode_85(data + hunk_size, buffer + 1, byte_length))
1171                         goto corrupt;
1172                 hunk_size = newsize;
1173                 buffer += llen;
1174                 size -= llen;
1175         }
1176
1177         frag = xcalloc(1, sizeof(*frag));
1178         frag->patch = inflate_it(data, hunk_size, origlen);
1179         if (!frag->patch)
1180                 goto corrupt;
1181         free(data);
1182         frag->size = origlen;
1183         *buf_p = buffer;
1184         *sz_p = size;
1185         *used_p = used;
1186         frag->binary_patch_method = patch_method;
1187         return frag;
1188
1189  corrupt:
1190         free(data);
1191         *status_p = -1;
1192         error("corrupt binary patch at line %d: %.*s",
1193               linenr-1, llen-1, buffer);
1194         return NULL;
1195 }
1196
1197 static int parse_binary(char *buffer, unsigned long size, struct patch *patch)
1198 {
1199         /* We have read "GIT binary patch\n"; what follows is a line
1200          * that says the patch method (currently, either "literal" or
1201          * "delta") and the length of data before deflating; a
1202          * sequence of 'length-byte' followed by base-85 encoded data
1203          * follows.
1204          *
1205          * When a binary patch is reversible, there is another binary
1206          * hunk in the same format, starting with patch method (either
1207          * "literal" or "delta") with the length of data, and a sequence
1208          * of length-byte + base-85 encoded data, terminated with another
1209          * empty line.  This data, when applied to the postimage, produces
1210          * the preimage.
1211          */
1212         struct fragment *forward;
1213         struct fragment *reverse;
1214         int status;
1215         int used, used_1;
1216
1217         forward = parse_binary_hunk(&buffer, &size, &status, &used);
1218         if (!forward && !status)
1219                 /* there has to be one hunk (forward hunk) */
1220                 return error("unrecognized binary patch at line %d", linenr-1);
1221         if (status)
1222                 /* otherwise we already gave an error message */
1223                 return status;
1224
1225         reverse = parse_binary_hunk(&buffer, &size, &status, &used_1);
1226         if (reverse)
1227                 used += used_1;
1228         else if (status) {
1229                 /* not having reverse hunk is not an error, but having
1230                  * a corrupt reverse hunk is.
1231                  */
1232                 free((void*) forward->patch);
1233                 free(forward);
1234                 return status;
1235         }
1236         forward->next = reverse;
1237         patch->fragments = forward;
1238         patch->is_binary = 1;
1239         return used;
1240 }
1241
1242 static int parse_chunk(char *buffer, unsigned long size, struct patch *patch)
1243 {
1244         int hdrsize, patchsize;
1245         int offset = find_header(buffer, size, &hdrsize, patch);
1246
1247         if (offset < 0)
1248                 return offset;
1249
1250         patchsize = parse_single_patch(buffer + offset + hdrsize, size - offset - hdrsize, patch);
1251
1252         if (!patchsize) {
1253                 static const char *binhdr[] = {
1254                         "Binary files ",
1255                         "Files ",
1256                         NULL,
1257                 };
1258                 static const char git_binary[] = "GIT binary patch\n";
1259                 int i;
1260                 int hd = hdrsize + offset;
1261                 unsigned long llen = linelen(buffer + hd, size - hd);
1262
1263                 if (llen == sizeof(git_binary) - 1 &&
1264                     !memcmp(git_binary, buffer + hd, llen)) {
1265                         int used;
1266                         linenr++;
1267                         used = parse_binary(buffer + hd + llen,
1268                                             size - hd - llen, patch);
1269                         if (used)
1270                                 patchsize = used + llen;
1271                         else
1272                                 patchsize = 0;
1273                 }
1274                 else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
1275                         for (i = 0; binhdr[i]; i++) {
1276                                 int len = strlen(binhdr[i]);
1277                                 if (len < size - hd &&
1278                                     !memcmp(binhdr[i], buffer + hd, len)) {
1279                                         linenr++;
1280                                         patch->is_binary = 1;
1281                                         patchsize = llen;
1282                                         break;
1283                                 }
1284                         }
1285                 }
1286
1287                 /* Empty patch cannot be applied if it is a text patch
1288                  * without metadata change.  A binary patch appears
1289                  * empty to us here.
1290                  */
1291                 if ((apply || check) &&
1292                     (!patch->is_binary && !metadata_changes(patch)))
1293                         die("patch with only garbage at line %d", linenr);
1294         }
1295
1296         return offset + hdrsize + patchsize;
1297 }
1298
1299 #define swap(a,b) myswap((a),(b),sizeof(a))
1300
1301 #define myswap(a, b, size) do {         \
1302         unsigned char mytmp[size];      \
1303         memcpy(mytmp, &a, size);                \
1304         memcpy(&a, &b, size);           \
1305         memcpy(&b, mytmp, size);                \
1306 } while (0)
1307
1308 static void reverse_patches(struct patch *p)
1309 {
1310         for (; p; p = p->next) {
1311                 struct fragment *frag = p->fragments;
1312
1313                 swap(p->new_name, p->old_name);
1314                 swap(p->new_mode, p->old_mode);
1315                 swap(p->is_new, p->is_delete);
1316                 swap(p->lines_added, p->lines_deleted);
1317                 swap(p->old_sha1_prefix, p->new_sha1_prefix);
1318
1319                 for (; frag; frag = frag->next) {
1320                         swap(frag->newpos, frag->oldpos);
1321                         swap(frag->newlines, frag->oldlines);
1322                 }
1323         }
1324 }
1325
1326 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
1327 static const char minuses[]= "----------------------------------------------------------------------";
1328
1329 static void show_stats(struct patch *patch)
1330 {
1331         const char *prefix = "";
1332         char *name = patch->new_name;
1333         char *qname = NULL;
1334         int len, max, add, del, total;
1335
1336         if (!name)
1337                 name = patch->old_name;
1338
1339         if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
1340                 qname = xmalloc(len + 1);
1341                 quote_c_style(name, qname, NULL, 0);
1342                 name = qname;
1343         }
1344
1345         /*
1346          * "scale" the filename
1347          */
1348         len = strlen(name);
1349         max = max_len;
1350         if (max > 50)
1351                 max = 50;
1352         if (len > max) {
1353                 char *slash;
1354                 prefix = "...";
1355                 max -= 3;
1356                 name += len - max;
1357                 slash = strchr(name, '/');
1358                 if (slash)
1359                         name = slash;
1360         }
1361         len = max;
1362
1363         /*
1364          * scale the add/delete
1365          */
1366         max = max_change;
1367         if (max + len > 70)
1368                 max = 70 - len;
1369
1370         add = patch->lines_added;
1371         del = patch->lines_deleted;
1372         total = add + del;
1373
1374         if (max_change > 0) {
1375                 total = (total * max + max_change / 2) / max_change;
1376                 add = (add * max + max_change / 2) / max_change;
1377                 del = total - add;
1378         }
1379         if (patch->is_binary)
1380                 printf(" %s%-*s |  Bin\n", prefix, len, name);
1381         else
1382                 printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
1383                        len, name, patch->lines_added + patch->lines_deleted,
1384                        add, pluses, del, minuses);
1385         free(qname);
1386 }
1387
1388 static int read_old_data(struct stat *st, const char *path, void *buf, unsigned long size)
1389 {
1390         int fd;
1391         unsigned long got;
1392
1393         switch (st->st_mode & S_IFMT) {
1394         case S_IFLNK:
1395                 return readlink(path, buf, size);
1396         case S_IFREG:
1397                 fd = open(path, O_RDONLY);
1398                 if (fd < 0)
1399                         return error("unable to open %s", path);
1400                 got = 0;
1401                 for (;;) {
1402                         int ret = xread(fd, (char *) buf + got, size - got);
1403                         if (ret <= 0)
1404                                 break;
1405                         got += ret;
1406                 }
1407                 close(fd);
1408                 return got;
1409
1410         default:
1411                 return -1;
1412         }
1413 }
1414
1415 static int find_offset(const char *buf, unsigned long size, const char *fragment, unsigned long fragsize, int line, int *lines)
1416 {
1417         int i;
1418         unsigned long start, backwards, forwards;
1419
1420         if (fragsize > size)
1421                 return -1;
1422
1423         start = 0;
1424         if (line > 1) {
1425                 unsigned long offset = 0;
1426                 i = line-1;
1427                 while (offset + fragsize <= size) {
1428                         if (buf[offset++] == '\n') {
1429                                 start = offset;
1430                                 if (!--i)
1431                                         break;
1432                         }
1433                 }
1434         }
1435
1436         /* Exact line number? */
1437         if (!memcmp(buf + start, fragment, fragsize))
1438                 return start;
1439
1440         /*
1441          * There's probably some smart way to do this, but I'll leave
1442          * that to the smart and beautiful people. I'm simple and stupid.
1443          */
1444         backwards = start;
1445         forwards = start;
1446         for (i = 0; ; i++) {
1447                 unsigned long try;
1448                 int n;
1449
1450                 /* "backward" */
1451                 if (i & 1) {
1452                         if (!backwards) {
1453                                 if (forwards + fragsize > size)
1454                                         break;
1455                                 continue;
1456                         }
1457                         do {
1458                                 --backwards;
1459                         } while (backwards && buf[backwards-1] != '\n');
1460                         try = backwards;
1461                 } else {
1462                         while (forwards + fragsize <= size) {
1463                                 if (buf[forwards++] == '\n')
1464                                         break;
1465                         }
1466                         try = forwards;
1467                 }
1468
1469                 if (try + fragsize > size)
1470                         continue;
1471                 if (memcmp(buf + try, fragment, fragsize))
1472                         continue;
1473                 n = (i >> 1)+1;
1474                 if (i & 1)
1475                         n = -n;
1476                 *lines = n;
1477                 return try;
1478         }
1479
1480         /*
1481          * We should start searching forward and backward.
1482          */
1483         return -1;
1484 }
1485
1486 static void remove_first_line(const char **rbuf, int *rsize)
1487 {
1488         const char *buf = *rbuf;
1489         int size = *rsize;
1490         unsigned long offset;
1491         offset = 0;
1492         while (offset <= size) {
1493                 if (buf[offset++] == '\n')
1494                         break;
1495         }
1496         *rsize = size - offset;
1497         *rbuf = buf + offset;
1498 }
1499
1500 static void remove_last_line(const char **rbuf, int *rsize)
1501 {
1502         const char *buf = *rbuf;
1503         int size = *rsize;
1504         unsigned long offset;
1505         offset = size - 1;
1506         while (offset > 0) {
1507                 if (buf[--offset] == '\n')
1508                         break;
1509         }
1510         *rsize = offset + 1;
1511 }
1512
1513 struct buffer_desc {
1514         char *buffer;
1515         unsigned long size;
1516         unsigned long alloc;
1517 };
1518
1519 static int apply_line(char *output, const char *patch, int plen)
1520 {
1521         /* plen is number of bytes to be copied from patch,
1522          * starting at patch+1 (patch[0] is '+').  Typically
1523          * patch[plen] is '\n', unless this is the incomplete
1524          * last line.
1525          */
1526         int i;
1527         int add_nl_to_tail = 0;
1528         int fixed = 0;
1529         int last_tab_in_indent = -1;
1530         int last_space_in_indent = -1;
1531         int need_fix_leading_space = 0;
1532         char *buf;
1533
1534         if ((new_whitespace != strip_whitespace) || !whitespace_error) {
1535                 memcpy(output, patch + 1, plen);
1536                 return plen;
1537         }
1538
1539         if (1 < plen && isspace(patch[plen-1])) {
1540                 if (patch[plen] == '\n')
1541                         add_nl_to_tail = 1;
1542                 plen--;
1543                 while (0 < plen && isspace(patch[plen]))
1544                         plen--;
1545                 fixed = 1;
1546         }
1547
1548         for (i = 1; i < plen; i++) {
1549                 char ch = patch[i];
1550                 if (ch == '\t') {
1551                         last_tab_in_indent = i;
1552                         if (0 <= last_space_in_indent)
1553                                 need_fix_leading_space = 1;
1554                 }
1555                 else if (ch == ' ')
1556                         last_space_in_indent = i;
1557                 else
1558                         break;
1559         }
1560
1561         buf = output;
1562         if (need_fix_leading_space) {
1563                 /* between patch[1..last_tab_in_indent] strip the
1564                  * funny spaces, updating them to tab as needed.
1565                  */
1566                 for (i = 1; i < last_tab_in_indent; i++, plen--) {
1567                         char ch = patch[i];
1568                         if (ch != ' ')
1569                                 *output++ = ch;
1570                         else if ((i % 8) == 0)
1571                                 *output++ = '\t';
1572                 }
1573                 fixed = 1;
1574                 i = last_tab_in_indent;
1575         }
1576         else
1577                 i = 1;
1578
1579         memcpy(output, patch + i, plen);
1580         if (add_nl_to_tail)
1581                 output[plen++] = '\n';
1582         if (fixed)
1583                 applied_after_stripping++;
1584         return output + plen - buf;
1585 }
1586
1587 static int apply_one_fragment(struct buffer_desc *desc, struct fragment *frag, int inaccurate_eof)
1588 {
1589         int match_beginning, match_end;
1590         char *buf = desc->buffer;
1591         const char *patch = frag->patch;
1592         int offset, size = frag->size;
1593         char *old = xmalloc(size);
1594         char *new = xmalloc(size);
1595         const char *oldlines, *newlines;
1596         int oldsize = 0, newsize = 0;
1597         unsigned long leading, trailing;
1598         int pos, lines;
1599
1600         while (size > 0) {
1601                 char first;
1602                 int len = linelen(patch, size);
1603                 int plen;
1604
1605                 if (!len)
1606                         break;
1607
1608                 /*
1609                  * "plen" is how much of the line we should use for
1610                  * the actual patch data. Normally we just remove the
1611                  * first character on the line, but if the line is
1612                  * followed by "\ No newline", then we also remove the
1613                  * last one (which is the newline, of course).
1614                  */
1615                 plen = len-1;
1616                 if (len < size && patch[len] == '\\')
1617                         plen--;
1618                 first = *patch;
1619                 if (apply_in_reverse) {
1620                         if (first == '-')
1621                                 first = '+';
1622                         else if (first == '+')
1623                                 first = '-';
1624                 }
1625                 switch (first) {
1626                 case ' ':
1627                 case '-':
1628                         memcpy(old + oldsize, patch + 1, plen);
1629                         oldsize += plen;
1630                         if (first == '-')
1631                                 break;
1632                 /* Fall-through for ' ' */
1633                 case '+':
1634                         if (first != '+' || !no_add)
1635                                 newsize += apply_line(new + newsize, patch,
1636                                                       plen);
1637                         break;
1638                 case '@': case '\\':
1639                         /* Ignore it, we already handled it */
1640                         break;
1641                 default:
1642                         return -1;
1643                 }
1644                 patch += len;
1645                 size -= len;
1646         }
1647
1648         if (inaccurate_eof && oldsize > 0 && old[oldsize - 1] == '\n' &&
1649                         newsize > 0 && new[newsize - 1] == '\n') {
1650                 oldsize--;
1651                 newsize--;
1652         }
1653
1654         oldlines = old;
1655         newlines = new;
1656         leading = frag->leading;
1657         trailing = frag->trailing;
1658
1659         /*
1660          * If we don't have any leading/trailing data in the patch,
1661          * we want it to match at the beginning/end of the file.
1662          *
1663          * But that would break if the patch is generated with
1664          * --unified=0; sane people wouldn't do that to cause us
1665          * trouble, but we try to please not so sane ones as well.
1666          */
1667         if (unidiff_zero) {
1668                 match_beginning = (!leading && !frag->oldpos);
1669                 match_end = 0;
1670         }
1671         else {
1672                 match_beginning = !leading && (frag->oldpos == 1);
1673                 match_end = !trailing;
1674         }
1675
1676         lines = 0;
1677         pos = frag->newpos;
1678         for (;;) {
1679                 offset = find_offset(buf, desc->size,
1680                                      oldlines, oldsize, pos, &lines);
1681                 if (match_end && offset + oldsize != desc->size)
1682                         offset = -1;
1683                 if (match_beginning && offset)
1684                         offset = -1;
1685                 if (offset >= 0) {
1686                         int diff = newsize - oldsize;
1687                         unsigned long size = desc->size + diff;
1688                         unsigned long alloc = desc->alloc;
1689
1690                         /* Warn if it was necessary to reduce the number
1691                          * of context lines.
1692                          */
1693                         if ((leading != frag->leading) ||
1694                             (trailing != frag->trailing))
1695                                 fprintf(stderr, "Context reduced to (%ld/%ld)"
1696                                         " to apply fragment at %d\n",
1697                                         leading, trailing, pos + lines);
1698
1699                         if (size > alloc) {
1700                                 alloc = size + 8192;
1701                                 desc->alloc = alloc;
1702                                 buf = xrealloc(buf, alloc);
1703                                 desc->buffer = buf;
1704                         }
1705                         desc->size = size;
1706                         memmove(buf + offset + newsize,
1707                                 buf + offset + oldsize,
1708                                 size - offset - newsize);
1709                         memcpy(buf + offset, newlines, newsize);
1710                         offset = 0;
1711
1712                         break;
1713                 }
1714
1715                 /* Am I at my context limits? */
1716                 if ((leading <= p_context) && (trailing <= p_context))
1717                         break;
1718                 if (match_beginning || match_end) {
1719                         match_beginning = match_end = 0;
1720                         continue;
1721                 }
1722                 /* Reduce the number of context lines
1723                  * Reduce both leading and trailing if they are equal
1724                  * otherwise just reduce the larger context.
1725                  */
1726                 if (leading >= trailing) {
1727                         remove_first_line(&oldlines, &oldsize);
1728                         remove_first_line(&newlines, &newsize);
1729                         pos--;
1730                         leading--;
1731                 }
1732                 if (trailing > leading) {
1733                         remove_last_line(&oldlines, &oldsize);
1734                         remove_last_line(&newlines, &newsize);
1735                         trailing--;
1736                 }
1737         }
1738
1739         free(old);
1740         free(new);
1741         return offset;
1742 }
1743
1744 static int apply_binary_fragment(struct buffer_desc *desc, struct patch *patch)
1745 {
1746         unsigned long dst_size;
1747         struct fragment *fragment = patch->fragments;
1748         void *data;
1749         void *result;
1750
1751         /* Binary patch is irreversible without the optional second hunk */
1752         if (apply_in_reverse) {
1753                 if (!fragment->next)
1754                         return error("cannot reverse-apply a binary patch "
1755                                      "without the reverse hunk to '%s'",
1756                                      patch->new_name
1757                                      ? patch->new_name : patch->old_name);
1758                 fragment = fragment->next;
1759         }
1760         data = (void*) fragment->patch;
1761         switch (fragment->binary_patch_method) {
1762         case BINARY_DELTA_DEFLATED:
1763                 result = patch_delta(desc->buffer, desc->size,
1764                                      data,
1765                                      fragment->size,
1766                                      &dst_size);
1767                 free(desc->buffer);
1768                 desc->buffer = result;
1769                 break;
1770         case BINARY_LITERAL_DEFLATED:
1771                 free(desc->buffer);
1772                 desc->buffer = data;
1773                 dst_size = fragment->size;
1774                 break;
1775         }
1776         if (!desc->buffer)
1777                 return -1;
1778         desc->size = desc->alloc = dst_size;
1779         return 0;
1780 }
1781
1782 static int apply_binary(struct buffer_desc *desc, struct patch *patch)
1783 {
1784         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1785         unsigned char sha1[20];
1786         unsigned char hdr[50];
1787         int hdrlen;
1788
1789         /* For safety, we require patch index line to contain
1790          * full 40-byte textual SHA1 for old and new, at least for now.
1791          */
1792         if (strlen(patch->old_sha1_prefix) != 40 ||
1793             strlen(patch->new_sha1_prefix) != 40 ||
1794             get_sha1_hex(patch->old_sha1_prefix, sha1) ||
1795             get_sha1_hex(patch->new_sha1_prefix, sha1))
1796                 return error("cannot apply binary patch to '%s' "
1797                              "without full index line", name);
1798
1799         if (patch->old_name) {
1800                 /* See if the old one matches what the patch
1801                  * applies to.
1802                  */
1803                 write_sha1_file_prepare(desc->buffer, desc->size,
1804                                         blob_type, sha1, hdr, &hdrlen);
1805                 if (strcmp(sha1_to_hex(sha1), patch->old_sha1_prefix))
1806                         return error("the patch applies to '%s' (%s), "
1807                                      "which does not match the "
1808                                      "current contents.",
1809                                      name, sha1_to_hex(sha1));
1810         }
1811         else {
1812                 /* Otherwise, the old one must be empty. */
1813                 if (desc->size)
1814                         return error("the patch applies to an empty "
1815                                      "'%s' but it is not empty", name);
1816         }
1817
1818         get_sha1_hex(patch->new_sha1_prefix, sha1);
1819         if (is_null_sha1(sha1)) {
1820                 free(desc->buffer);
1821                 desc->alloc = desc->size = 0;
1822                 desc->buffer = NULL;
1823                 return 0; /* deletion patch */
1824         }
1825
1826         if (has_sha1_file(sha1)) {
1827                 /* We already have the postimage */
1828                 char type[10];
1829                 unsigned long size;
1830
1831                 free(desc->buffer);
1832                 desc->buffer = read_sha1_file(sha1, type, &size);
1833                 if (!desc->buffer)
1834                         return error("the necessary postimage %s for "
1835                                      "'%s' cannot be read",
1836                                      patch->new_sha1_prefix, name);
1837                 desc->alloc = desc->size = size;
1838         }
1839         else {
1840                 /* We have verified desc matches the preimage;
1841                  * apply the patch data to it, which is stored
1842                  * in the patch->fragments->{patch,size}.
1843                  */
1844                 if (apply_binary_fragment(desc, patch))
1845                         return error("binary patch does not apply to '%s'",
1846                                      name);
1847
1848                 /* verify that the result matches */
1849                 write_sha1_file_prepare(desc->buffer, desc->size, blob_type,
1850                                         sha1, hdr, &hdrlen);
1851                 if (strcmp(sha1_to_hex(sha1), patch->new_sha1_prefix))
1852                         return error("binary patch to '%s' creates incorrect result (expecting %s, got %s)", name, patch->new_sha1_prefix, sha1_to_hex(sha1));
1853         }
1854
1855         return 0;
1856 }
1857
1858 static int apply_fragments(struct buffer_desc *desc, struct patch *patch)
1859 {
1860         struct fragment *frag = patch->fragments;
1861         const char *name = patch->old_name ? patch->old_name : patch->new_name;
1862
1863         if (patch->is_binary)
1864                 return apply_binary(desc, patch);
1865
1866         while (frag) {
1867                 if (apply_one_fragment(desc, frag, patch->inaccurate_eof)) {
1868                         error("patch failed: %s:%ld", name, frag->oldpos);
1869                         if (!apply_with_reject)
1870                                 return -1;
1871                         frag->rejected = 1;
1872                 }
1873                 frag = frag->next;
1874         }
1875         return 0;
1876 }
1877
1878 static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *ce)
1879 {
1880         char *buf;
1881         unsigned long size, alloc;
1882         struct buffer_desc desc;
1883
1884         size = 0;
1885         alloc = 0;
1886         buf = NULL;
1887         if (cached) {
1888                 if (ce) {
1889                         char type[20];
1890                         buf = read_sha1_file(ce->sha1, type, &size);
1891                         if (!buf)
1892                                 return error("read of %s failed",
1893                                              patch->old_name);
1894                         alloc = size;
1895                 }
1896         }
1897         else if (patch->old_name) {
1898                 size = st->st_size;
1899                 alloc = size + 8192;
1900                 buf = xmalloc(alloc);
1901                 if (read_old_data(st, patch->old_name, buf, alloc) != size)
1902                         return error("read of %s failed", patch->old_name);
1903         }
1904
1905         desc.size = size;
1906         desc.alloc = alloc;
1907         desc.buffer = buf;
1908
1909         if (apply_fragments(&desc, patch) < 0)
1910                 return -1; /* note with --reject this succeeds. */
1911
1912         /* NUL terminate the result */
1913         if (desc.alloc <= desc.size)
1914                 desc.buffer = xrealloc(desc.buffer, desc.size + 1);
1915         desc.buffer[desc.size] = 0;
1916
1917         patch->result = desc.buffer;
1918         patch->resultsize = desc.size;
1919
1920         if (0 < patch->is_delete && patch->resultsize)
1921                 return error("removal patch leaves file contents");
1922
1923         return 0;
1924 }
1925
1926 static int check_patch(struct patch *patch, struct patch *prev_patch)
1927 {
1928         struct stat st;
1929         const char *old_name = patch->old_name;
1930         const char *new_name = patch->new_name;
1931         const char *name = old_name ? old_name : new_name;
1932         struct cache_entry *ce = NULL;
1933         int ok_if_exists;
1934
1935         patch->rejected = 1; /* we will drop this after we succeed */
1936         if (old_name) {
1937                 int changed = 0;
1938                 int stat_ret = 0;
1939                 unsigned st_mode = 0;
1940
1941                 if (!cached)
1942                         stat_ret = lstat(old_name, &st);
1943                 if (check_index) {
1944                         int pos = cache_name_pos(old_name, strlen(old_name));
1945                         if (pos < 0)
1946                                 return error("%s: does not exist in index",
1947                                              old_name);
1948                         ce = active_cache[pos];
1949                         if (stat_ret < 0) {
1950                                 struct checkout costate;
1951                                 if (errno != ENOENT)
1952                                         return error("%s: %s", old_name,
1953                                                      strerror(errno));
1954                                 /* checkout */
1955                                 costate.base_dir = "";
1956                                 costate.base_dir_len = 0;
1957                                 costate.force = 0;
1958                                 costate.quiet = 0;
1959                                 costate.not_new = 0;
1960                                 costate.refresh_cache = 1;
1961                                 if (checkout_entry(ce,
1962                                                    &costate,
1963                                                    NULL) ||
1964                                     lstat(old_name, &st))
1965                                         return -1;
1966                         }
1967                         if (!cached)
1968                                 changed = ce_match_stat(ce, &st, 1);
1969                         if (changed)
1970                                 return error("%s: does not match index",
1971                                              old_name);
1972                         if (cached)
1973                                 st_mode = ntohl(ce->ce_mode);
1974                 }
1975                 else if (stat_ret < 0)
1976                         return error("%s: %s", old_name, strerror(errno));
1977
1978                 if (!cached)
1979                         st_mode = ntohl(create_ce_mode(st.st_mode));
1980
1981                 if (patch->is_new < 0)
1982                         patch->is_new = 0;
1983                 if (!patch->old_mode)
1984                         patch->old_mode = st_mode;
1985                 if ((st_mode ^ patch->old_mode) & S_IFMT)
1986                         return error("%s: wrong type", old_name);
1987                 if (st_mode != patch->old_mode)
1988                         fprintf(stderr, "warning: %s has type %o, expected %o\n",
1989                                 old_name, st_mode, patch->old_mode);
1990         }
1991
1992         if (new_name && prev_patch && 0 < prev_patch->is_delete &&
1993             !strcmp(prev_patch->old_name, new_name))
1994                 /* A type-change diff is always split into a patch to
1995                  * delete old, immediately followed by a patch to
1996                  * create new (see diff.c::run_diff()); in such a case
1997                  * it is Ok that the entry to be deleted by the
1998                  * previous patch is still in the working tree and in
1999                  * the index.
2000                  */
2001                 ok_if_exists = 1;
2002         else
2003                 ok_if_exists = 0;
2004
2005         if (new_name &&
2006             ((0 < patch->is_new) | (0 < patch->is_rename) | patch->is_copy)) {
2007                 if (check_index &&
2008                     cache_name_pos(new_name, strlen(new_name)) >= 0 &&
2009                     !ok_if_exists)
2010                         return error("%s: already exists in index", new_name);
2011                 if (!cached) {
2012                         struct stat nst;
2013                         if (!lstat(new_name, &nst)) {
2014                                 if (S_ISDIR(nst.st_mode) || ok_if_exists)
2015                                         ; /* ok */
2016                                 else
2017                                         return error("%s: already exists in working directory", new_name);
2018                         }
2019                         else if ((errno != ENOENT) && (errno != ENOTDIR))
2020                                 return error("%s: %s", new_name, strerror(errno));
2021                 }
2022                 if (!patch->new_mode) {
2023                         if (0 < patch->is_new)
2024                                 patch->new_mode = S_IFREG | 0644;
2025                         else
2026                                 patch->new_mode = patch->old_mode;
2027                 }
2028         }
2029
2030         if (new_name && old_name) {
2031                 int same = !strcmp(old_name, new_name);
2032                 if (!patch->new_mode)
2033                         patch->new_mode = patch->old_mode;
2034                 if ((patch->old_mode ^ patch->new_mode) & S_IFMT)
2035                         return error("new mode (%o) of %s does not match old mode (%o)%s%s",
2036                                 patch->new_mode, new_name, patch->old_mode,
2037                                 same ? "" : " of ", same ? "" : old_name);
2038         }
2039
2040         if (apply_data(patch, &st, ce) < 0)
2041                 return error("%s: patch does not apply", name);
2042         patch->rejected = 0;
2043         return 0;
2044 }
2045
2046 static int check_patch_list(struct patch *patch)
2047 {
2048         struct patch *prev_patch = NULL;
2049         int err = 0;
2050
2051         for (prev_patch = NULL; patch ; patch = patch->next) {
2052                 if (apply_verbosely)
2053                         say_patch_name(stderr,
2054                                        "Checking patch ", patch, "...\n");
2055                 err |= check_patch(patch, prev_patch);
2056                 prev_patch = patch;
2057         }
2058         return err;
2059 }
2060
2061 static void show_index_list(struct patch *list)
2062 {
2063         struct patch *patch;
2064
2065         /* Once we start supporting the reverse patch, it may be
2066          * worth showing the new sha1 prefix, but until then...
2067          */
2068         for (patch = list; patch; patch = patch->next) {
2069                 const unsigned char *sha1_ptr;
2070                 unsigned char sha1[20];
2071                 const char *name;
2072
2073                 name = patch->old_name ? patch->old_name : patch->new_name;
2074                 if (0 < patch->is_new)
2075                         sha1_ptr = null_sha1;
2076                 else if (get_sha1(patch->old_sha1_prefix, sha1))
2077                         die("sha1 information is lacking or useless (%s).",
2078                             name);
2079                 else
2080                         sha1_ptr = sha1;
2081
2082                 printf("%06o %s ",patch->old_mode, sha1_to_hex(sha1_ptr));
2083                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
2084                         quote_c_style(name, NULL, stdout, 0);
2085                 else
2086                         fputs(name, stdout);
2087                 putchar(line_termination);
2088         }
2089 }
2090
2091 static void stat_patch_list(struct patch *patch)
2092 {
2093         int files, adds, dels;
2094
2095         for (files = adds = dels = 0 ; patch ; patch = patch->next) {
2096                 files++;
2097                 adds += patch->lines_added;
2098                 dels += patch->lines_deleted;
2099                 show_stats(patch);
2100         }
2101
2102         printf(" %d files changed, %d insertions(+), %d deletions(-)\n", files, adds, dels);
2103 }
2104
2105 static void numstat_patch_list(struct patch *patch)
2106 {
2107         for ( ; patch; patch = patch->next) {
2108                 const char *name;
2109                 name = patch->new_name ? patch->new_name : patch->old_name;
2110                 printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
2111                 if (line_termination && quote_c_style(name, NULL, NULL, 0))
2112                         quote_c_style(name, NULL, stdout, 0);
2113                 else
2114                         fputs(name, stdout);
2115                 putchar('\n');
2116         }
2117 }
2118
2119 static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
2120 {
2121         if (mode)
2122                 printf(" %s mode %06o %s\n", newdelete, mode, name);
2123         else
2124                 printf(" %s %s\n", newdelete, name);
2125 }
2126
2127 static void show_mode_change(struct patch *p, int show_name)
2128 {
2129         if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
2130                 if (show_name)
2131                         printf(" mode change %06o => %06o %s\n",
2132                                p->old_mode, p->new_mode, p->new_name);
2133                 else
2134                         printf(" mode change %06o => %06o\n",
2135                                p->old_mode, p->new_mode);
2136         }
2137 }
2138
2139 static void show_rename_copy(struct patch *p)
2140 {
2141         const char *renamecopy = p->is_rename ? "rename" : "copy";
2142         const char *old, *new;
2143
2144         /* Find common prefix */
2145         old = p->old_name;
2146         new = p->new_name;
2147         while (1) {
2148                 const char *slash_old, *slash_new;
2149                 slash_old = strchr(old, '/');
2150                 slash_new = strchr(new, '/');
2151                 if (!slash_old ||
2152                     !slash_new ||
2153                     slash_old - old != slash_new - new ||
2154                     memcmp(old, new, slash_new - new))
2155                         break;
2156                 old = slash_old + 1;
2157                 new = slash_new + 1;
2158         }
2159         /* p->old_name thru old is the common prefix, and old and new
2160          * through the end of names are renames
2161          */
2162         if (old != p->old_name)
2163                 printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
2164                        (int)(old - p->old_name), p->old_name,
2165                        old, new, p->score);
2166         else
2167                 printf(" %s %s => %s (%d%%)\n", renamecopy,
2168                        p->old_name, p->new_name, p->score);
2169         show_mode_change(p, 0);
2170 }
2171
2172 static void summary_patch_list(struct patch *patch)
2173 {
2174         struct patch *p;
2175
2176         for (p = patch; p; p = p->next) {
2177                 if (p->is_new)
2178                         show_file_mode_name("create", p->new_mode, p->new_name);
2179                 else if (p->is_delete)
2180                         show_file_mode_name("delete", p->old_mode, p->old_name);
2181                 else {
2182                         if (p->is_rename || p->is_copy)
2183                                 show_rename_copy(p);
2184                         else {
2185                                 if (p->score) {
2186                                         printf(" rewrite %s (%d%%)\n",
2187                                                p->new_name, p->score);
2188                                         show_mode_change(p, 0);
2189                                 }
2190                                 else
2191                                         show_mode_change(p, 1);
2192                         }
2193                 }
2194         }
2195 }
2196
2197 static void patch_stats(struct patch *patch)
2198 {
2199         int lines = patch->lines_added + patch->lines_deleted;
2200
2201         if (lines > max_change)
2202                 max_change = lines;
2203         if (patch->old_name) {
2204                 int len = quote_c_style(patch->old_name, NULL, NULL, 0);
2205                 if (!len)
2206                         len = strlen(patch->old_name);
2207                 if (len > max_len)
2208                         max_len = len;
2209         }
2210         if (patch->new_name) {
2211                 int len = quote_c_style(patch->new_name, NULL, NULL, 0);
2212                 if (!len)
2213                         len = strlen(patch->new_name);
2214                 if (len > max_len)
2215                         max_len = len;
2216         }
2217 }
2218
2219 static void remove_file(struct patch *patch)
2220 {
2221         if (write_index) {
2222                 if (remove_file_from_cache(patch->old_name) < 0)
2223                         die("unable to remove %s from index", patch->old_name);
2224                 cache_tree_invalidate_path(active_cache_tree, patch->old_name);
2225         }
2226         if (!cached)
2227                 unlink(patch->old_name);
2228 }
2229
2230 static void add_index_file(const char *path, unsigned mode, void *buf, unsigned long size)
2231 {
2232         struct stat st;
2233         struct cache_entry *ce;
2234         int namelen = strlen(path);
2235         unsigned ce_size = cache_entry_size(namelen);
2236
2237         if (!write_index)
2238                 return;
2239
2240         ce = xcalloc(1, ce_size);
2241         memcpy(ce->name, path, namelen);
2242         ce->ce_mode = create_ce_mode(mode);
2243         ce->ce_flags = htons(namelen);
2244         if (!cached) {
2245                 if (lstat(path, &st) < 0)
2246                         die("unable to stat newly created file %s", path);
2247                 fill_stat_cache_info(ce, &st);
2248         }
2249         if (write_sha1_file(buf, size, blob_type, ce->sha1) < 0)
2250                 die("unable to create backing store for newly created file %s", path);
2251         if (add_cache_entry(ce, ADD_CACHE_OK_TO_ADD) < 0)
2252                 die("unable to add cache entry for %s", path);
2253 }
2254
2255 static int try_create_file(const char *path, unsigned int mode, const char *buf, unsigned long size)
2256 {
2257         int fd;
2258
2259         if (S_ISLNK(mode))
2260                 /* Although buf:size is counted string, it also is NUL
2261                  * terminated.
2262                  */
2263                 return symlink(buf, path);
2264         fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
2265         if (fd < 0)
2266                 return -1;
2267         while (size) {
2268                 int written = xwrite(fd, buf, size);
2269                 if (written < 0)
2270                         die("writing file %s: %s", path, strerror(errno));
2271                 if (!written)
2272                         die("out of space writing file %s", path);
2273                 buf += written;
2274                 size -= written;
2275         }
2276         if (close(fd) < 0)
2277                 die("closing file %s: %s", path, strerror(errno));
2278         return 0;
2279 }
2280
2281 /*
2282  * We optimistically assume that the directories exist,
2283  * which is true 99% of the time anyway. If they don't,
2284  * we create them and try again.
2285  */
2286 static void create_one_file(char *path, unsigned mode, const char *buf, unsigned long size)
2287 {
2288         if (cached)
2289                 return;
2290         if (!try_create_file(path, mode, buf, size))
2291                 return;
2292
2293         if (errno == ENOENT) {
2294                 if (safe_create_leading_directories(path))
2295                         return;
2296                 if (!try_create_file(path, mode, buf, size))
2297                         return;
2298         }
2299
2300         if (errno == EEXIST || errno == EACCES) {
2301                 /* We may be trying to create a file where a directory
2302                  * used to be.
2303                  */
2304                 struct stat st;
2305                 errno = 0;
2306                 if (!lstat(path, &st) && S_ISDIR(st.st_mode) && !rmdir(path))
2307                         errno = EEXIST;
2308         }
2309
2310         if (errno == EEXIST) {
2311                 unsigned int nr = getpid();
2312
2313                 for (;;) {
2314                         const char *newpath;
2315                         newpath = mkpath("%s~%u", path, nr);
2316                         if (!try_create_file(newpath, mode, buf, size)) {
2317                                 if (!rename(newpath, path))
2318                                         return;
2319                                 unlink(newpath);
2320                                 break;
2321                         }
2322                         if (errno != EEXIST)
2323                                 break;
2324                         ++nr;
2325                 }
2326         }
2327         die("unable to write file %s mode %o", path, mode);
2328 }
2329
2330 static void create_file(struct patch *patch)
2331 {
2332         char *path = patch->new_name;
2333         unsigned mode = patch->new_mode;
2334         unsigned long size = patch->resultsize;
2335         char *buf = patch->result;
2336
2337         if (!mode)
2338                 mode = S_IFREG | 0644;
2339         create_one_file(path, mode, buf, size);
2340         add_index_file(path, mode, buf, size);
2341         cache_tree_invalidate_path(active_cache_tree, path);
2342 }
2343
2344 /* phase zero is to remove, phase one is to create */
2345 static void write_out_one_result(struct patch *patch, int phase)
2346 {
2347         if (patch->is_delete > 0) {
2348                 if (phase == 0)
2349                         remove_file(patch);
2350                 return;
2351         }
2352         if (patch->is_new > 0 || patch->is_copy) {
2353                 if (phase == 1)
2354                         create_file(patch);
2355                 return;
2356         }
2357         /*
2358          * Rename or modification boils down to the same
2359          * thing: remove the old, write the new
2360          */
2361         if (phase == 0)
2362                 remove_file(patch);
2363         if (phase == 1)
2364                 create_file(patch);
2365 }
2366
2367 static int write_out_one_reject(struct patch *patch)
2368 {
2369         FILE *rej;
2370         char namebuf[PATH_MAX];
2371         struct fragment *frag;
2372         int cnt = 0;
2373
2374         for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
2375                 if (!frag->rejected)
2376                         continue;
2377                 cnt++;
2378         }
2379
2380         if (!cnt) {
2381                 if (apply_verbosely)
2382                         say_patch_name(stderr,
2383                                        "Applied patch ", patch, " cleanly.\n");
2384                 return 0;
2385         }
2386
2387         /* This should not happen, because a removal patch that leaves
2388          * contents are marked "rejected" at the patch level.
2389          */
2390         if (!patch->new_name)
2391                 die("internal error");
2392
2393         /* Say this even without --verbose */
2394         say_patch_name(stderr, "Applying patch ", patch, " with");
2395         fprintf(stderr, " %d rejects...\n", cnt);
2396
2397         cnt = strlen(patch->new_name);
2398         if (ARRAY_SIZE(namebuf) <= cnt + 5) {
2399                 cnt = ARRAY_SIZE(namebuf) - 5;
2400                 fprintf(stderr,
2401                         "warning: truncating .rej filename to %.*s.rej",
2402                         cnt - 1, patch->new_name);
2403         }
2404         memcpy(namebuf, patch->new_name, cnt);
2405         memcpy(namebuf + cnt, ".rej", 5);
2406
2407         rej = fopen(namebuf, "w");
2408         if (!rej)
2409                 return error("cannot open %s: %s", namebuf, strerror(errno));
2410
2411         /* Normal git tools never deal with .rej, so do not pretend
2412          * this is a git patch by saying --git nor give extended
2413          * headers.  While at it, maybe please "kompare" that wants
2414          * the trailing TAB and some garbage at the end of line ;-).
2415          */
2416         fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
2417                 patch->new_name, patch->new_name);
2418         for (cnt = 1, frag = patch->fragments;
2419              frag;
2420              cnt++, frag = frag->next) {
2421                 if (!frag->rejected) {
2422                         fprintf(stderr, "Hunk #%d applied cleanly.\n", cnt);
2423                         continue;
2424                 }
2425                 fprintf(stderr, "Rejected hunk #%d.\n", cnt);
2426                 fprintf(rej, "%.*s", frag->size, frag->patch);
2427                 if (frag->patch[frag->size-1] != '\n')
2428                         fputc('\n', rej);
2429         }
2430         fclose(rej);
2431         return -1;
2432 }
2433
2434 static int write_out_results(struct patch *list, int skipped_patch)
2435 {
2436         int phase;
2437         int errs = 0;
2438         struct patch *l;
2439
2440         if (!list && !skipped_patch)
2441                 return error("No changes");
2442
2443         for (phase = 0; phase < 2; phase++) {
2444                 l = list;
2445                 while (l) {
2446                         if (l->rejected)
2447                                 errs = 1;
2448                         else {
2449                                 write_out_one_result(l, phase);
2450                                 if (phase == 1 && write_out_one_reject(l))
2451                                         errs = 1;
2452                         }
2453                         l = l->next;
2454                 }
2455         }
2456         return errs;
2457 }
2458
2459 static struct lock_file lock_file;
2460
2461 static struct excludes {
2462         struct excludes *next;
2463         const char *path;
2464 } *excludes;
2465
2466 static int use_patch(struct patch *p)
2467 {
2468         const char *pathname = p->new_name ? p->new_name : p->old_name;
2469         struct excludes *x = excludes;
2470         while (x) {
2471                 if (fnmatch(x->path, pathname, 0) == 0)
2472                         return 0;
2473                 x = x->next;
2474         }
2475         if (0 < prefix_length) {
2476                 int pathlen = strlen(pathname);
2477                 if (pathlen <= prefix_length ||
2478                     memcmp(prefix, pathname, prefix_length))
2479                         return 0;
2480         }
2481         return 1;
2482 }
2483
2484 static int apply_patch(int fd, const char *filename, int inaccurate_eof)
2485 {
2486         unsigned long offset, size;
2487         char *buffer = read_patch_file(fd, &size);
2488         struct patch *list = NULL, **listp = &list;
2489         int skipped_patch = 0;
2490
2491         patch_input_file = filename;
2492         if (!buffer)
2493                 return -1;
2494         offset = 0;
2495         while (size > 0) {
2496                 struct patch *patch;
2497                 int nr;
2498
2499                 patch = xcalloc(1, sizeof(*patch));
2500                 patch->inaccurate_eof = inaccurate_eof;
2501                 nr = parse_chunk(buffer + offset, size, patch);
2502                 if (nr < 0)
2503                         break;
2504                 if (apply_in_reverse)
2505                         reverse_patches(patch);
2506                 if (use_patch(patch)) {
2507                         patch_stats(patch);
2508                         *listp = patch;
2509                         listp = &patch->next;
2510                 } else {
2511                         /* perhaps free it a bit better? */
2512                         free(patch);
2513                         skipped_patch++;
2514                 }
2515                 offset += nr;
2516                 size -= nr;
2517         }
2518
2519         if (whitespace_error && (new_whitespace == error_on_whitespace))
2520                 apply = 0;
2521
2522         write_index = check_index && apply;
2523         if (write_index && newfd < 0)
2524                 newfd = hold_lock_file_for_update(&lock_file,
2525                                                   get_index_file(), 1);
2526         if (check_index) {
2527                 if (read_cache() < 0)
2528                         die("unable to read index file");
2529         }
2530
2531         if ((check || apply) &&
2532             check_patch_list(list) < 0 &&
2533             !apply_with_reject)
2534                 exit(1);
2535
2536         if (apply && write_out_results(list, skipped_patch))
2537                 exit(1);
2538
2539         if (show_index_info)
2540                 show_index_list(list);
2541
2542         if (diffstat)
2543                 stat_patch_list(list);
2544
2545         if (numstat)
2546                 numstat_patch_list(list);
2547
2548         if (summary)
2549                 summary_patch_list(list);
2550
2551         free(buffer);
2552         return 0;
2553 }
2554
2555 static int git_apply_config(const char *var, const char *value)
2556 {
2557         if (!strcmp(var, "apply.whitespace")) {
2558                 apply_default_whitespace = xstrdup(value);
2559                 return 0;
2560         }
2561         return git_default_config(var, value);
2562 }
2563
2564
2565 int cmd_apply(int argc, const char **argv, const char *prefix)
2566 {
2567         int i;
2568         int read_stdin = 1;
2569         int inaccurate_eof = 0;
2570         int errs = 0;
2571
2572         const char *whitespace_option = NULL;
2573
2574         for (i = 1; i < argc; i++) {
2575                 const char *arg = argv[i];
2576                 char *end;
2577                 int fd;
2578
2579                 if (!strcmp(arg, "-")) {
2580                         errs |= apply_patch(0, "<stdin>", inaccurate_eof);
2581                         read_stdin = 0;
2582                         continue;
2583                 }
2584                 if (!strncmp(arg, "--exclude=", 10)) {
2585                         struct excludes *x = xmalloc(sizeof(*x));
2586                         x->path = arg + 10;
2587                         x->next = excludes;
2588                         excludes = x;
2589                         continue;
2590                 }
2591                 if (!strncmp(arg, "-p", 2)) {
2592                         p_value = atoi(arg + 2);
2593                         continue;
2594                 }
2595                 if (!strcmp(arg, "--no-add")) {
2596                         no_add = 1;
2597                         continue;
2598                 }
2599                 if (!strcmp(arg, "--stat")) {
2600                         apply = 0;
2601                         diffstat = 1;
2602                         continue;
2603                 }
2604                 if (!strcmp(arg, "--allow-binary-replacement") ||
2605                     !strcmp(arg, "--binary")) {
2606                         continue; /* now no-op */
2607                 }
2608                 if (!strcmp(arg, "--numstat")) {
2609                         apply = 0;
2610                         numstat = 1;
2611                         continue;
2612                 }
2613                 if (!strcmp(arg, "--summary")) {
2614                         apply = 0;
2615                         summary = 1;
2616                         continue;
2617                 }
2618                 if (!strcmp(arg, "--check")) {
2619                         apply = 0;
2620                         check = 1;
2621                         continue;
2622                 }
2623                 if (!strcmp(arg, "--index")) {
2624                         check_index = 1;
2625                         continue;
2626                 }
2627                 if (!strcmp(arg, "--cached")) {
2628                         check_index = 1;
2629                         cached = 1;
2630                         continue;
2631                 }
2632                 if (!strcmp(arg, "--apply")) {
2633                         apply = 1;
2634                         continue;
2635                 }
2636                 if (!strcmp(arg, "--index-info")) {
2637                         apply = 0;
2638                         show_index_info = 1;
2639                         continue;
2640                 }
2641                 if (!strcmp(arg, "-z")) {
2642                         line_termination = 0;
2643                         continue;
2644                 }
2645                 if (!strncmp(arg, "-C", 2)) {
2646                         p_context = strtoul(arg + 2, &end, 0);
2647                         if (*end != '\0')
2648                                 die("unrecognized context count '%s'", arg + 2);
2649                         continue;
2650                 }
2651                 if (!strncmp(arg, "--whitespace=", 13)) {
2652                         whitespace_option = arg + 13;
2653                         parse_whitespace_option(arg + 13);
2654                         continue;
2655                 }
2656                 if (!strcmp(arg, "-R") || !strcmp(arg, "--reverse")) {
2657                         apply_in_reverse = 1;
2658                         continue;
2659                 }
2660                 if (!strcmp(arg, "--unidiff-zero")) {
2661                         unidiff_zero = 1;
2662                         continue;
2663                 }
2664                 if (!strcmp(arg, "--reject")) {
2665                         apply = apply_with_reject = apply_verbosely = 1;
2666                         continue;
2667                 }
2668                 if (!strcmp(arg, "--verbose")) {
2669                         apply_verbosely = 1;
2670                         continue;
2671                 }
2672                 if (!strcmp(arg, "--inaccurate-eof")) {
2673                         inaccurate_eof = 1;
2674                         continue;
2675                 }
2676
2677                 if (check_index && prefix_length < 0) {
2678                         prefix = setup_git_directory();
2679                         prefix_length = prefix ? strlen(prefix) : 0;
2680                         git_config(git_apply_config);
2681                         if (!whitespace_option && apply_default_whitespace)
2682                                 parse_whitespace_option(apply_default_whitespace);
2683                 }
2684                 if (0 < prefix_length)
2685                         arg = prefix_filename(prefix, prefix_length, arg);
2686
2687                 fd = open(arg, O_RDONLY);
2688                 if (fd < 0)
2689                         usage(apply_usage);
2690                 read_stdin = 0;
2691                 set_default_whitespace_mode(whitespace_option);
2692                 errs |= apply_patch(fd, arg, inaccurate_eof);
2693                 close(fd);
2694         }
2695         set_default_whitespace_mode(whitespace_option);
2696         if (read_stdin)
2697                 errs |= apply_patch(0, "<stdin>", inaccurate_eof);
2698         if (whitespace_error) {
2699                 if (squelch_whitespace_errors &&
2700                     squelch_whitespace_errors < whitespace_error) {
2701                         int squelched =
2702                                 whitespace_error - squelch_whitespace_errors;
2703                         fprintf(stderr, "warning: squelched %d "
2704                                 "whitespace error%s\n",
2705                                 squelched,
2706                                 squelched == 1 ? "" : "s");
2707                 }
2708                 if (new_whitespace == error_on_whitespace)
2709                         die("%d line%s add%s trailing whitespaces.",
2710                             whitespace_error,
2711                             whitespace_error == 1 ? "" : "s",
2712                             whitespace_error == 1 ? "s" : "");
2713                 if (applied_after_stripping)
2714                         fprintf(stderr, "warning: %d line%s applied after"
2715                                 " stripping trailing whitespaces.\n",
2716                                 applied_after_stripping,
2717                                 applied_after_stripping == 1 ? "" : "s");
2718                 else if (whitespace_error)
2719                         fprintf(stderr, "warning: %d line%s add%s trailing"
2720                                 " whitespaces.\n",
2721                                 whitespace_error,
2722                                 whitespace_error == 1 ? "" : "s",
2723                                 whitespace_error == 1 ? "s" : "");
2724         }
2725
2726         if (write_index) {
2727                 if (write_cache(newfd, active_cache, active_nr) ||
2728                     close(newfd) || commit_lock_file(&lock_file))
2729                         die("Unable to write new index file");
2730         }
2731
2732         return !!errs;
2733 }