]> asedeno.scripts.mit.edu Git - git.git/blob - builtin-commit.c
Fix --signoff in builtin-commit differently.
[git.git] / builtin-commit.c
1 /*
2  * Builtin "git commit"
3  *
4  * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>
5  * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
6  */
7
8 #include "cache.h"
9 #include "cache-tree.h"
10 #include "dir.h"
11 #include "builtin.h"
12 #include "diff.h"
13 #include "diffcore.h"
14 #include "commit.h"
15 #include "revision.h"
16 #include "wt-status.h"
17 #include "run-command.h"
18 #include "refs.h"
19 #include "log-tree.h"
20 #include "strbuf.h"
21 #include "utf8.h"
22 #include "parse-options.h"
23 #include "path-list.h"
24
25 static const char * const builtin_commit_usage[] = {
26         "git-commit [options] [--] <filepattern>...",
27         NULL
28 };
29
30 static unsigned char head_sha1[20], merge_head_sha1[20];
31 static char *use_message_buffer;
32 static const char commit_editmsg[] = "COMMIT_EDITMSG";
33 static struct lock_file index_lock; /* real index */
34 static struct lock_file false_lock; /* used only for partial commits */
35 static enum {
36         COMMIT_AS_IS = 1,
37         COMMIT_NORMAL,
38         COMMIT_PARTIAL,
39 } commit_style;
40
41 static char *logfile, *force_author, *template_file;
42 static char *edit_message, *use_message;
43 static int all, edit_flag, also, interactive, only, amend, signoff;
44 static int quiet, verbose, untracked_files, no_verify;
45
46 static int no_edit, initial_commit, in_merge;
47 const char *only_include_assumed;
48 struct strbuf message;
49
50 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
51 {
52         struct strbuf *buf = opt->value;
53         if (unset)
54                 strbuf_setlen(buf, 0);
55         else {
56                 strbuf_addstr(buf, arg);
57                 strbuf_addch(buf, '\n');
58                 strbuf_addch(buf, '\n');
59         }
60         return 0;
61 }
62
63 static struct option builtin_commit_options[] = {
64         OPT__QUIET(&quiet),
65         OPT__VERBOSE(&verbose),
66         OPT_GROUP("Commit message options"),
67
68         OPT_STRING('F', "file", &logfile, "FILE", "read log from file"),
69         OPT_STRING(0, "author", &force_author, "AUTHOR", "override author for commit"),
70         OPT_CALLBACK('m', "message", &message, "MESSAGE", "specify commit message", opt_parse_m),
71         OPT_STRING('c', "reedit-message", &edit_message, "COMMIT", "reuse and edit message from specified commit "),
72         OPT_STRING('C', "reuse-message", &use_message, "COMMIT", "reuse message from specified commit"),
73         OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by: header"),
74         OPT_STRING('t', "template", &template_file, "FILE", "use specified template file"),
75         OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
76
77         OPT_GROUP("Commit contents options"),
78         OPT_BOOLEAN('a', "all", &all, "commit all changed files"),
79         OPT_BOOLEAN('i', "include", &also, "add specified files to index for commit"),
80         OPT_BOOLEAN(0, "interactive", &interactive, "interactively add files"),
81         OPT_BOOLEAN('o', "only", &only, ""),
82         OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
83         OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
84         OPT_BOOLEAN(0, "untracked-files", &untracked_files, "show all untracked files"),
85
86         OPT_END()
87 };
88
89 static void rollback_index_files(void)
90 {
91         switch (commit_style) {
92         case COMMIT_AS_IS:
93                 break; /* nothing to do */
94         case COMMIT_NORMAL:
95                 rollback_lock_file(&index_lock);
96                 break;
97         case COMMIT_PARTIAL:
98                 rollback_lock_file(&index_lock);
99                 rollback_lock_file(&false_lock);
100                 break;
101         }
102 }
103
104 static void commit_index_files(void)
105 {
106         switch (commit_style) {
107         case COMMIT_AS_IS:
108                 break; /* nothing to do */
109         case COMMIT_NORMAL:
110                 commit_lock_file(&index_lock);
111                 break;
112         case COMMIT_PARTIAL:
113                 commit_lock_file(&index_lock);
114                 rollback_lock_file(&false_lock);
115                 break;
116         }
117 }
118
119 /*
120  * Take a union of paths in the index and the named tree (typically, "HEAD"),
121  * and return the paths that match the given pattern in list.
122  */
123 static int list_paths(struct path_list *list, const char *with_tree,
124                       const char *prefix, const char **pattern)
125 {
126         int i;
127         char *m;
128
129         for (i = 0; pattern[i]; i++)
130                 ;
131         m = xcalloc(1, i);
132
133         if (with_tree)
134                 overlay_tree_on_cache(with_tree, prefix);
135
136         for (i = 0; i < active_nr; i++) {
137                 struct cache_entry *ce = active_cache[i];
138                 if (ce->ce_flags & htons(CE_UPDATE))
139                         continue;
140                 if (!pathspec_match(pattern, m, ce->name, 0))
141                         continue;
142                 path_list_insert(ce->name, list);
143         }
144
145         return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
146 }
147
148 static void add_remove_files(struct path_list *list)
149 {
150         int i;
151         for (i = 0; i < list->nr; i++) {
152                 struct path_list_item *p = &(list->items[i]);
153                 if (file_exists(p->path))
154                         add_file_to_cache(p->path, 0);
155                 else
156                         remove_file_from_cache(p->path);
157         }
158 }
159
160 static char *prepare_index(const char **files, const char *prefix)
161 {
162         int fd;
163         struct tree *tree;
164         struct path_list partial;
165         const char **pathspec = NULL;
166
167         if (interactive) {
168                 interactive_add();
169                 commit_style = COMMIT_AS_IS;
170                 return get_index_file();
171         }
172
173         if (read_cache() < 0)
174                 die("index file corrupt");
175
176         if (*files)
177                 pathspec = get_pathspec(prefix, files);
178
179         /*
180          * Non partial, non as-is commit.
181          *
182          * (1) get the real index;
183          * (2) update the_index as necessary;
184          * (3) write the_index out to the real index (still locked);
185          * (4) return the name of the locked index file.
186          *
187          * The caller should run hooks on the locked real index, and
188          * (A) if all goes well, commit the real index;
189          * (B) on failure, rollback the real index.
190          */
191         if (all || (also && pathspec && *pathspec)) {
192                 int fd = hold_locked_index(&index_lock, 1);
193                 add_files_to_cache(0, also ? prefix : NULL, pathspec);
194                 refresh_cache(REFRESH_QUIET);
195                 if (write_cache(fd, active_cache, active_nr) || close(fd))
196                         die("unable to write new_index file");
197                 commit_style = COMMIT_NORMAL;
198                 return index_lock.filename;
199         }
200
201         /*
202          * As-is commit.
203          *
204          * (1) return the name of the real index file.
205          *
206          * The caller should run hooks on the real index, and run
207          * hooks on the real index, and create commit from the_index.
208          * We still need to refresh the index here.
209          */
210         if (!pathspec || !*pathspec) {
211                 fd = hold_locked_index(&index_lock, 1);
212                 refresh_cache(REFRESH_QUIET);
213                 if (write_cache(fd, active_cache, active_nr) ||
214                     close(fd) || commit_locked_index(&index_lock))
215                         die("unable to write new_index file");
216                 commit_style = COMMIT_AS_IS;
217                 return get_index_file();
218         }
219
220         /*
221          * A partial commit.
222          *
223          * (0) find the set of affected paths;
224          * (1) get lock on the real index file;
225          * (2) update the_index with the given paths;
226          * (3) write the_index out to the real index (still locked);
227          * (4) get lock on the false index file;
228          * (5) reset the_index from HEAD;
229          * (6) update the_index the same way as (2);
230          * (7) write the_index out to the false index file;
231          * (8) return the name of the false index file (still locked);
232          *
233          * The caller should run hooks on the locked false index, and
234          * create commit from it.  Then
235          * (A) if all goes well, commit the real index;
236          * (B) on failure, rollback the real index;
237          * In either case, rollback the false index.
238          */
239         commit_style = COMMIT_PARTIAL;
240
241         if (file_exists(git_path("MERGE_HEAD")))
242                 die("cannot do a partial commit during a merge.");
243
244         memset(&partial, 0, sizeof(partial));
245         partial.strdup_paths = 1;
246         if (list_paths(&partial, initial_commit ? NULL : "HEAD", prefix, pathspec))
247                 exit(1);
248
249         discard_cache();
250         if (read_cache() < 0)
251                 die("cannot read the index");
252
253         fd = hold_locked_index(&index_lock, 1);
254         add_remove_files(&partial);
255         refresh_cache(REFRESH_QUIET);
256         if (write_cache(fd, active_cache, active_nr) || close(fd))
257                 die("unable to write new_index file");
258
259         fd = hold_lock_file_for_update(&false_lock,
260                                        git_path("next-index-%d", getpid()), 1);
261         discard_cache();
262         if (!initial_commit) {
263                 tree = parse_tree_indirect(head_sha1);
264                 if (!tree)
265                         die("failed to unpack HEAD tree object");
266                 if (read_tree(tree, 0, NULL))
267                         die("failed to read HEAD tree object");
268         }
269         add_remove_files(&partial);
270         refresh_cache(REFRESH_QUIET);
271
272         if (write_cache(fd, active_cache, active_nr) || close(fd))
273                 die("unable to write temporary index file");
274         return false_lock.filename;
275 }
276
277 static int run_status(FILE *fp, const char *index_file, const char *prefix)
278 {
279         struct wt_status s;
280
281         wt_status_prepare(&s);
282         s.prefix = prefix;
283
284         if (amend) {
285                 s.amend = 1;
286                 s.reference = "HEAD^1";
287         }
288         s.verbose = verbose;
289         s.untracked = untracked_files;
290         s.index_file = index_file;
291         s.fp = fp;
292
293         wt_status_print(&s);
294
295         return s.commitable;
296 }
297
298 static const char sign_off_header[] = "Signed-off-by: ";
299
300 static int prepare_log_message(const char *index_file, const char *prefix)
301 {
302         struct stat statbuf;
303         int commitable, saved_color_setting;
304         struct strbuf sb;
305         char *buffer;
306         FILE *fp;
307
308         strbuf_init(&sb, 0);
309         if (message.len) {
310                 strbuf_addbuf(&sb, &message);
311         } else if (logfile && !strcmp(logfile, "-")) {
312                 if (isatty(0))
313                         fprintf(stderr, "(reading log message from standard input)\n");
314                 if (strbuf_read(&sb, 0, 0) < 0)
315                         die("could not read log from standard input");
316         } else if (logfile) {
317                 if (strbuf_read_file(&sb, logfile, 0) < 0)
318                         die("could not read log file '%s': %s",
319                             logfile, strerror(errno));
320         } else if (use_message) {
321                 buffer = strstr(use_message_buffer, "\n\n");
322                 if (!buffer || buffer[2] == '\0')
323                         die("commit has empty message");
324                 strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
325         } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
326                 if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
327                         die("could not read MERGE_MSG: %s", strerror(errno));
328         } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
329                 if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
330                         die("could not read SQUASH_MSG: %s", strerror(errno));
331         } else if (template_file && !stat(template_file, &statbuf)) {
332                 if (strbuf_read_file(&sb, template_file, 0) < 0)
333                         die("could not read %s: %s",
334                             template_file, strerror(errno));
335         }
336
337         fp = fopen(git_path(commit_editmsg), "w");
338         if (fp == NULL)
339                 die("could not open %s", git_path(commit_editmsg));
340
341         stripspace(&sb, 0);
342
343         if (signoff) {
344                 struct strbuf sob;
345                 int i;
346
347                 strbuf_init(&sob, 0);
348                 strbuf_addstr(&sob, sign_off_header);
349                 strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
350                                              getenv("GIT_COMMITTER_EMAIL")));
351                 strbuf_addch(&sob, '\n');
352                 for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
353                         ; /* do nothing */
354                 if (prefixcmp(sb.buf + i, sob.buf)) {
355                         if (prefixcmp(sb.buf + i, sign_off_header))
356                                 strbuf_addch(&sb, '\n');
357                         strbuf_addbuf(&sb, &sob);
358                 }
359                 strbuf_release(&sob);
360         }
361
362         if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
363                 die("could not write commit template: %s", strerror(errno));
364
365         strbuf_release(&sb);
366
367         if (no_edit) {
368                 struct rev_info rev;
369                 unsigned char sha1[40];
370
371                 fclose(fp);
372
373                 if (!active_nr && read_cache() < 0)
374                         die("Cannot read index");
375
376                 if (get_sha1("HEAD", sha1) != 0)
377                         return !!active_nr;
378
379                 init_revisions(&rev, "");
380                 rev.abbrev = 0;
381                 setup_revisions(0, NULL, &rev, "HEAD");
382                 DIFF_OPT_SET(&rev.diffopt, QUIET);
383                 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
384                 run_diff_index(&rev, 1 /* cached */);
385
386                 return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
387         }
388
389         if (in_merge && !no_edit)
390                 fprintf(fp,
391                         "#\n"
392                         "# It looks like you may be committing a MERGE.\n"
393                         "# If this is not correct, please remove the file\n"
394                         "#      %s\n"
395                         "# and try again.\n"
396                         "#\n",
397                         git_path("MERGE_HEAD"));
398
399         fprintf(fp,
400                 "\n"
401                 "# Please enter the commit message for your changes.\n"
402                 "# (Comment lines starting with '#' will not be included)\n");
403         if (only_include_assumed)
404                 fprintf(fp, "# %s\n", only_include_assumed);
405
406         saved_color_setting = wt_status_use_color;
407         wt_status_use_color = 0;
408         commitable = run_status(fp, index_file, prefix);
409         wt_status_use_color = saved_color_setting;
410
411         fclose(fp);
412
413         return commitable;
414 }
415
416 /*
417  * Find out if the message starting at position 'start' in the strbuf
418  * contains only whitespace and Signed-off-by lines.
419  */
420 static int message_is_empty(struct strbuf *sb, int start)
421 {
422         struct strbuf tmpl;
423         const char *nl;
424         int eol, i;
425
426         /* See if the template is just a prefix of the message. */
427         strbuf_init(&tmpl, 0);
428         if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
429                 stripspace(&tmpl, 1);
430                 if (start + tmpl.len <= sb->len &&
431                     memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
432                         start += tmpl.len;
433         }
434         strbuf_release(&tmpl);
435
436         /* Check if the rest is just whitespace and Signed-of-by's. */
437         for (i = start; i < sb->len; i++) {
438                 nl = memchr(sb->buf + i, '\n', sb->len - i);
439                 if (nl)
440                         eol = nl - sb->buf;
441                 else
442                         eol = sb->len;
443
444                 if (strlen(sign_off_header) <= eol - i &&
445                     !prefixcmp(sb->buf + i, sign_off_header)) {
446                         i = eol;
447                         continue;
448                 }
449                 while (i < eol)
450                         if (!isspace(sb->buf[i++]))
451                                 return 0;
452         }
453
454         return 1;
455 }
456
457 static void determine_author_info(struct strbuf *sb)
458 {
459         char *name, *email, *date;
460
461         name = getenv("GIT_AUTHOR_NAME");
462         email = getenv("GIT_AUTHOR_EMAIL");
463         date = getenv("GIT_AUTHOR_DATE");
464
465         if (use_message) {
466                 const char *a, *lb, *rb, *eol;
467
468                 a = strstr(use_message_buffer, "\nauthor ");
469                 if (!a)
470                         die("invalid commit: %s", use_message);
471
472                 lb = strstr(a + 8, " <");
473                 rb = strstr(a + 8, "> ");
474                 eol = strchr(a + 8, '\n');
475                 if (!lb || !rb || !eol)
476                         die("invalid commit: %s", use_message);
477
478                 name = xstrndup(a + 8, lb - (a + 8));
479                 email = xstrndup(lb + 2, rb - (lb + 2));
480                 date = xstrndup(rb + 2, eol - (rb + 2));
481         }
482
483         if (force_author) {
484                 const char *lb = strstr(force_author, " <");
485                 const char *rb = strchr(force_author, '>');
486
487                 if (!lb || !rb)
488                         die("malformed --author parameter");
489                 name = xstrndup(force_author, lb - force_author);
490                 email = xstrndup(lb + 2, rb - (lb + 2));
491         }
492
493         strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, 1));
494 }
495
496 static int parse_and_validate_options(int argc, const char *argv[])
497 {
498         int f = 0;
499
500         argc = parse_options(argc, argv, builtin_commit_options,
501                              builtin_commit_usage, 0);
502
503         if (logfile || message.len || use_message)
504                 no_edit = 1;
505         if (edit_flag)
506                 no_edit = 0;
507
508         if (get_sha1("HEAD", head_sha1))
509                 initial_commit = 1;
510
511         if (!get_sha1("MERGE_HEAD", merge_head_sha1))
512                 in_merge = 1;
513
514         /* Sanity check options */
515         if (amend && initial_commit)
516                 die("You have nothing to amend.");
517         if (amend && in_merge)
518                 die("You are in the middle of a merge -- cannot amend.");
519
520         if (use_message)
521                 f++;
522         if (edit_message)
523                 f++;
524         if (logfile)
525                 f++;
526         if (f > 1)
527                 die("Only one of -c/-C/-F can be used.");
528         if (message.len && f > 0)
529                 die("Option -m cannot be combined with -c/-C/-F.");
530         if (edit_message)
531                 use_message = edit_message;
532         if (amend)
533                 use_message = "HEAD";
534         if (use_message) {
535                 unsigned char sha1[20];
536                 static char utf8[] = "UTF-8";
537                 const char *out_enc;
538                 char *enc, *end;
539                 struct commit *commit;
540
541                 if (get_sha1(use_message, sha1))
542                         die("could not lookup commit %s", use_message);
543                 commit = lookup_commit(sha1);
544                 if (!commit || parse_commit(commit))
545                         die("could not parse commit %s", use_message);
546
547                 enc = strstr(commit->buffer, "\nencoding");
548                 if (enc) {
549                         end = strchr(enc + 10, '\n');
550                         enc = xstrndup(enc + 10, end - (enc + 10));
551                 } else {
552                         enc = utf8;
553                 }
554                 out_enc = git_commit_encoding ? git_commit_encoding : utf8;
555
556                 if (strcmp(out_enc, enc))
557                         use_message_buffer =
558                                 reencode_string(commit->buffer, out_enc, enc);
559
560                 /*
561                  * If we failed to reencode the buffer, just copy it
562                  * byte for byte so the user can try to fix it up.
563                  * This also handles the case where input and output
564                  * encodings are identical.
565                  */
566                 if (use_message_buffer == NULL)
567                         use_message_buffer = xstrdup(commit->buffer);
568                 if (enc != utf8)
569                         free(enc);
570         }
571
572         if (!!also + !!only + !!all + !!interactive > 1)
573                 die("Only one of --include/--only/--all/--interactive can be used.");
574         if (argc == 0 && (also || (only && !amend)))
575                 die("No paths with --include/--only does not make sense.");
576         if (argc == 0 && only && amend)
577                 only_include_assumed = "Clever... amending the last one with dirty index.";
578         if (argc > 0 && !also && !only) {
579                 only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
580                 also = 0;
581         }
582
583         if (all && argc > 0)
584                 die("Paths with -a does not make sense.");
585         else if (interactive && argc > 0)
586                 die("Paths with --interactive does not make sense.");
587
588         return argc;
589 }
590
591 int cmd_status(int argc, const char **argv, const char *prefix)
592 {
593         const char *index_file;
594         int commitable;
595
596         git_config(git_status_config);
597
598         argc = parse_and_validate_options(argc, argv);
599
600         index_file = prepare_index(argv, prefix);
601
602         commitable = run_status(stdout, index_file, prefix);
603
604         rollback_index_files();
605
606         return commitable ? 0 : 1;
607 }
608
609 static int run_hook(const char *index_file, const char *name, const char *arg)
610 {
611         struct child_process hook;
612         const char *argv[3], *env[2];
613         char index[PATH_MAX];
614
615         argv[0] = git_path("hooks/%s", name);
616         argv[1] = arg;
617         argv[2] = NULL;
618         snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
619         env[0] = index;
620         env[1] = NULL;
621
622         if (access(argv[0], X_OK) < 0)
623                 return 0;
624
625         memset(&hook, 0, sizeof(hook));
626         hook.argv = argv;
627         hook.no_stdin = 1;
628         hook.stdout_to_stderr = 1;
629         hook.env = env;
630
631         return run_command(&hook);
632 }
633
634 static void print_summary(const char *prefix, const unsigned char *sha1)
635 {
636         struct rev_info rev;
637         struct commit *commit;
638
639         commit = lookup_commit(sha1);
640         if (!commit)
641                 die("couldn't look up newly created commit");
642         if (!commit || parse_commit(commit))
643                 die("could not parse newly created commit");
644
645         init_revisions(&rev, prefix);
646         setup_revisions(0, NULL, &rev, NULL);
647
648         rev.abbrev = 0;
649         rev.diff = 1;
650         rev.diffopt.output_format =
651                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
652
653         rev.verbose_header = 1;
654         rev.show_root_diff = 1;
655         rev.commit_format = get_commit_format("format:%h: %s");
656         rev.always_show_header = 1;
657
658         printf("Created %scommit ", initial_commit ? "initial " : "");
659
660         log_tree_commit(&rev, commit);
661         printf("\n");
662 }
663
664 int git_commit_config(const char *k, const char *v)
665 {
666         if (!strcmp(k, "commit.template")) {
667                 template_file = xstrdup(v);
668                 return 0;
669         }
670
671         return git_status_config(k, v);
672 }
673
674 static const char commit_utf8_warn[] =
675 "Warning: commit message does not conform to UTF-8.\n"
676 "You may want to amend it after fixing the message, or set the config\n"
677 "variable i18n.commitencoding to the encoding your project uses.\n";
678
679 int cmd_commit(int argc, const char **argv, const char *prefix)
680 {
681         int header_len;
682         struct strbuf sb;
683         const char *index_file, *reflog_msg;
684         char *nl, *p;
685         unsigned char commit_sha1[20];
686         struct ref_lock *ref_lock;
687
688         git_config(git_commit_config);
689
690         argc = parse_and_validate_options(argc, argv);
691
692         index_file = prepare_index(argv, prefix);
693
694         if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
695                 rollback_index_files();
696                 return 1;
697         }
698
699         if (!prepare_log_message(index_file, prefix) && !in_merge) {
700                 run_status(stdout, index_file, prefix);
701                 rollback_index_files();
702                 unlink(commit_editmsg);
703                 return 1;
704         }
705
706         /*
707          * Re-read the index as pre-commit hook could have updated it,
708          * and write it out as a tree.
709          */
710         discard_cache();
711         read_cache_from(index_file);
712         if (!active_cache_tree)
713                 active_cache_tree = cache_tree();
714         if (cache_tree_update(active_cache_tree,
715                               active_cache, active_nr, 0, 0) < 0) {
716                 rollback_index_files();
717                 die("Error building trees");
718         }
719
720         /*
721          * The commit object
722          */
723         strbuf_init(&sb, 0);
724         strbuf_addf(&sb, "tree %s\n",
725                     sha1_to_hex(active_cache_tree->sha1));
726
727         /* Determine parents */
728         if (initial_commit) {
729                 reflog_msg = "commit (initial)";
730         } else if (amend) {
731                 struct commit_list *c;
732                 struct commit *commit;
733
734                 reflog_msg = "commit (amend)";
735                 commit = lookup_commit(head_sha1);
736                 if (!commit || parse_commit(commit))
737                         die("could not parse HEAD commit");
738
739                 for (c = commit->parents; c; c = c->next)
740                         strbuf_addf(&sb, "parent %s\n",
741                                       sha1_to_hex(c->item->object.sha1));
742         } else if (in_merge) {
743                 struct strbuf m;
744                 FILE *fp;
745
746                 reflog_msg = "commit (merge)";
747                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
748                 strbuf_init(&m, 0);
749                 fp = fopen(git_path("MERGE_HEAD"), "r");
750                 if (fp == NULL)
751                         die("could not open %s for reading: %s",
752                             git_path("MERGE_HEAD"), strerror(errno));
753                 while (strbuf_getline(&m, fp, '\n') != EOF)
754                         strbuf_addf(&sb, "parent %s\n", m.buf);
755                 fclose(fp);
756                 strbuf_release(&m);
757         } else {
758                 reflog_msg = "commit";
759                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
760         }
761
762         determine_author_info(&sb);
763         strbuf_addf(&sb, "committer %s\n", git_committer_info(1));
764         if (!is_encoding_utf8(git_commit_encoding))
765                 strbuf_addf(&sb, "encoding %s\n", git_commit_encoding);
766         strbuf_addch(&sb, '\n');
767
768         /* Get the commit message and validate it */
769         header_len = sb.len;
770         if (!no_edit) {
771                 char index[PATH_MAX];
772                 const char *env[2] = { index, NULL };
773                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
774                 launch_editor(git_path(commit_editmsg), &sb, env);
775         } else if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
776                 rollback_index_files();
777                 die("could not read commit message");
778         }
779         if (run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
780                 rollback_index_files();
781                 exit(1);
782         }
783
784         /* Truncate the message just before the diff, if any. */
785         p = strstr(sb.buf, "\ndiff --git a/");
786         if (p != NULL)
787                 strbuf_setlen(&sb, p - sb.buf + 1);
788
789         stripspace(&sb, 1);
790         if (sb.len < header_len || message_is_empty(&sb, header_len)) {
791                 rollback_index_files();
792                 die("no commit message?  aborting commit.");
793         }
794         strbuf_addch(&sb, '\0');
795         if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))
796                 fprintf(stderr, commit_utf8_warn);
797
798         if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
799                 rollback_index_files();
800                 die("failed to write commit object");
801         }
802
803         ref_lock = lock_any_ref_for_update("HEAD",
804                                            initial_commit ? NULL : head_sha1,
805                                            0);
806
807         nl = strchr(sb.buf + header_len, '\n');
808         if (nl)
809                 strbuf_setlen(&sb, nl + 1 - sb.buf);
810         else
811                 strbuf_addch(&sb, '\n');
812         strbuf_remove(&sb, 0, header_len);
813         strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
814         strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
815
816         if (!ref_lock) {
817                 rollback_index_files();
818                 die("cannot lock HEAD ref");
819         }
820         if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
821                 rollback_index_files();
822                 die("cannot update HEAD ref");
823         }
824
825         unlink(git_path("MERGE_HEAD"));
826         unlink(git_path("MERGE_MSG"));
827
828         commit_index_files();
829
830         rerere();
831         run_hook(get_index_file(), "post-commit", NULL);
832         if (!quiet)
833                 print_summary(prefix, commit_sha1);
834
835         return 0;
836 }