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[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  */
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"
25 static const char * const builtin_commit_usage[] = {
26         "git-commit [options] [--] <filepattern>...",
27         NULL
28 };
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;
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;
46 static int no_edit, initial_commit, in_merge;
47 const char *only_include_assumed;
48 struct strbuf message;
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 }
63 static struct option builtin_commit_options[] = {
64         OPT__QUIET(&quiet),
65         OPT__VERBOSE(&verbose),
66         OPT_GROUP("Commit message options"),
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"),
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"),
86         OPT_END()
87 };
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         }
104 static void commit_index_files(void)
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         }
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)
126         int i;
127         char *m;
129         for (i = 0; pattern[i]; i++)
130                 ;
131         m = xcalloc(1, i);
133         if (with_tree)
134                 overlay_tree_on_cache(with_tree, prefix);
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         }
145         return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
148 static void add_remove_files(struct path_list *list)
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         }
160 static char *prepare_index(const char **files, const char *prefix)
162         int fd;
163         struct tree *tree;
164         struct path_list partial;
165         const char **pathspec = NULL;
167         if (interactive) {
168                 interactive_add();
169                 commit_style = COMMIT_AS_IS;
170                 return get_index_file();
171         }
173         if (read_cache() < 0)
174                 die("index file corrupt");
176         if (*files)
177                 pathspec = get_pathspec(prefix, files);
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         }
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         }
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;
241         if (file_exists(git_path("MERGE_HEAD")))
242                 die("cannot do a partial commit during a merge.");
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);
249         discard_cache();
250         if (read_cache() < 0)
251                 die("cannot read the index");
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");
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);
272         if (write_cache(fd, active_cache, active_nr) || close(fd))
273                 die("unable to write temporary index file");
274         return false_lock.filename;
277 static int run_status(FILE *fp, const char *index_file, const char *prefix)
279         struct wt_status s;
281         wt_status_prepare(&s);
282         s.prefix = prefix;
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;
293         wt_status_print(&s);
295         return s.commitable;
298 static const char sign_off_header[] = "Signed-off-by: ";
300 static int prepare_log_message(const char *index_file, const char *prefix)
302         struct stat statbuf;
303         int commitable, saved_color_setting;
304         struct strbuf sb;
305         char *buffer;
306         FILE *fp;
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         }
337         fp = fopen(git_path(commit_editmsg), "w");
338         if (fp == NULL)
339                 die("could not open %s\n", git_path(commit_editmsg));
341         stripspace(&sb, 0);
343         if (signoff) {
344                 struct strbuf sob;
345                 int i;
347                 strbuf_init(&sob, 0);
348                 strbuf_addstr(&sob, sign_off_header);
349                 strbuf_addstr(&sob, fmt_ident(getenv("GIT_COMMITTER_NAME"),
350                                               getenv("GIT_COMMITTER_EMAIL"),
351                                               "", 1));
352                 strbuf_addch(&sob, '\n');
354                 for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
355                         ; /* do nothing */
356                 if (prefixcmp(sb.buf + i, sob.buf)) {
357                         if (prefixcmp(sb.buf + i, sign_off_header))
358                                 strbuf_addch(&sb, '\n');
359                         strbuf_addbuf(&sb, &sob);
360                 }
361                 strbuf_release(&sob);
362         }
364         if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
365                 die("could not write commit template: %s\n",
366                     strerror(errno));
368         strbuf_release(&sb);
370         if (no_edit) {
371                 struct rev_info rev;
372                 unsigned char sha1[40];
374                 fclose(fp);
376                 if (!active_nr && read_cache() < 0)
377                         die("Cannot read index");
379                 if (get_sha1("HEAD", sha1) != 0)
380                         return !!active_nr;
382                 init_revisions(&rev, "");
383                 rev.abbrev = 0;
384                 setup_revisions(0, NULL, &rev, "HEAD");
385                 DIFF_OPT_SET(&rev.diffopt, QUIET);
386                 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
387                 run_diff_index(&rev, 1 /* cached */);
389                 return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
390         }
392         if (in_merge && !no_edit)
393                 fprintf(fp,
394                         "#\n"
395                         "# It looks like you may be committing a MERGE.\n"
396                         "# If this is not correct, please remove the file\n"
397                         "#      %s\n"
398                         "# and try again.\n"
399                         "#\n",
400                         git_path("MERGE_HEAD"));
402         fprintf(fp,
403                 "\n"
404                 "# Please enter the commit message for your changes.\n"
405                 "# (Comment lines starting with '#' will not be included)\n");
406         if (only_include_assumed)
407                 fprintf(fp, "# %s\n", only_include_assumed);
409         saved_color_setting = wt_status_use_color;
410         wt_status_use_color = 0;
411         commitable = run_status(fp, index_file, prefix);
412         wt_status_use_color = saved_color_setting;
414         fclose(fp);
416         return commitable;
419 /*
420  * Find out if the message starting at position 'start' in the strbuf
421  * contains only whitespace and Signed-off-by lines.
422  */
423 static int message_is_empty(struct strbuf *sb, int start)
425         struct strbuf tmpl;
426         const char *nl;
427         int eol, i;
429         /* See if the template is just a prefix of the message. */
430         strbuf_init(&tmpl, 0);
431         if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
432                 stripspace(&tmpl, 1);
433                 if (start + tmpl.len <= sb->len &&
434                     memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
435                         start += tmpl.len;
436         }
437         strbuf_release(&tmpl);
439         /* Check if the rest is just whitespace and Signed-of-by's. */
440         for (i = start; i < sb->len; i++) {
441                 nl = memchr(sb->buf + i, '\n', sb->len - i);
442                 if (nl)
443                         eol = nl - sb->buf;
444                 else
445                         eol = sb->len;
447                 if (strlen(sign_off_header) <= eol - i &&
448                     !prefixcmp(sb->buf + i, sign_off_header)) {
449                         i = eol;
450                         continue;
451                 }
452                 while (i < eol)
453                         if (!isspace(sb->buf[i++]))
454                                 return 0;
455         }
457         return 1;
460 static void determine_author_info(struct strbuf *sb)
462         char *name, *email, *date;
464         name = getenv("GIT_AUTHOR_NAME");
465         email = getenv("GIT_AUTHOR_EMAIL");
466         date = getenv("GIT_AUTHOR_DATE");
468         if (use_message) {
469                 const char *a, *lb, *rb, *eol;
471                 a = strstr(use_message_buffer, "\nauthor ");
472                 if (!a)
473                         die("invalid commit: %s\n", use_message);
475                 lb = strstr(a + 8, " <");
476                 rb = strstr(a + 8, "> ");
477                 eol = strchr(a + 8, '\n');
478                 if (!lb || !rb || !eol)
479                         die("invalid commit: %s\n", use_message);
481                 name = xstrndup(a + 8, lb - (a + 8));
482                 email = xstrndup(lb + 2, rb - (lb + 2));
483                 date = xstrndup(rb + 2, eol - (rb + 2));
484         }
486         if (force_author) {
487                 const char *lb = strstr(force_author, " <");
488                 const char *rb = strchr(force_author, '>');
490                 if (!lb || !rb)
491                         die("malformed --author parameter\n");
492                 name = xstrndup(force_author, lb - force_author);
493                 email = xstrndup(lb + 2, rb - (lb + 2));
494         }
496         strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, 1));
499 static int parse_and_validate_options(int argc, const char *argv[])
501         int f = 0;
503         argc = parse_options(argc, argv, builtin_commit_options,
504                              builtin_commit_usage, 0);
506         if (logfile || message.len || use_message)
507                 no_edit = 1;
508         if (edit_flag)
509                 no_edit = 0;
511         if (get_sha1("HEAD", head_sha1))
512                 initial_commit = 1;
514         if (!get_sha1("MERGE_HEAD", merge_head_sha1))
515                 in_merge = 1;
517         /* Sanity check options */
518         if (amend && initial_commit)
519                 die("You have nothing to amend.");
520         if (amend && in_merge)
521                 die("You are in the middle of a merger -- cannot amend.");
523         if (use_message)
524                 f++;
525         if (edit_message)
526                 f++;
527         if (logfile)
528                 f++;
529         if (f > 1)
530                 die("Only one of -c/-C/-F can be used.");
531         if (message.len && f > 0)
532                 die("Option -m cannot be combined with -c/-C/-F.");
533         if (edit_message)
534                 use_message = edit_message;
535         if (amend)
536                 use_message = "HEAD";
537         if (use_message) {
538                 unsigned char sha1[20];
539                 static char utf8[] = "UTF-8";
540                 const char *out_enc;
541                 char *enc, *end;
542                 struct commit *commit;
544                 if (get_sha1(use_message, sha1))
545                         die("could not lookup commit %s", use_message);
546                 commit = lookup_commit(sha1);
547                 if (!commit || parse_commit(commit))
548                         die("could not parse commit %s", use_message);
550                 enc = strstr(commit->buffer, "\nencoding");
551                 if (enc) {
552                         end = strchr(enc + 10, '\n');
553                         enc = xstrndup(enc + 10, end - (enc + 10));
554                 } else {
555                         enc = utf8;
556                 }
557                 out_enc = git_commit_encoding ? git_commit_encoding : utf8;
559                 if (strcmp(out_enc, enc))
560                         use_message_buffer =
561                                 reencode_string(commit->buffer, out_enc, enc);
563                 /*
564                  * If we failed to reencode the buffer, just copy it
565                  * byte for byte so the user can try to fix it up.
566                  * This also handles the case where input and output
567                  * encodings are identical.
568                  */
569                 if (use_message_buffer == NULL)
570                         use_message_buffer = xstrdup(commit->buffer);
571                 if (enc != utf8)
572                         free(enc);
573         }
575         if (!!also + !!only + !!all + !!interactive > 1)
576                 die("Only one of --include/--only/--all/--interactive can be used.");
577         if (argc == 0 && (also || (only && !amend)))
578                 die("No paths with --include/--only does not make sense.");
579         if (argc == 0 && only && amend)
580                 only_include_assumed = "Clever... amending the last one with dirty index.";
581         if (argc > 0 && !also && !only) {
582                 only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
583                 also = 0;
584         }
586         if (all && argc > 0)
587                 die("Paths with -a does not make sense.");
588         else if (interactive && argc > 0)
589                 die("Paths with --interactive does not make sense.");
591         return argc;
594 int cmd_status(int argc, const char **argv, const char *prefix)
596         const char *index_file;
597         int commitable;
599         git_config(git_status_config);
601         argc = parse_and_validate_options(argc, argv);
603         index_file = prepare_index(argv, prefix);
605         commitable = run_status(stdout, index_file, prefix);
607         rollback_index_files();
609         return commitable ? 0 : 1;
612 static int run_hook(const char *index_file, const char *name, const char *arg)
614         struct child_process hook;
615         const char *argv[3], *env[2];
616         char index[PATH_MAX];
618         argv[0] = git_path("hooks/%s", name);
619         argv[1] = arg;
620         argv[2] = NULL;
621         snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
622         env[0] = index;
623         env[1] = NULL;
625         if (access(argv[0], X_OK) < 0)
626                 return 0;
628         memset(&hook, 0, sizeof(hook));
629         hook.argv = argv;
630         hook.no_stdin = 1;
631         hook.stdout_to_stderr = 1;
632         hook.env = env;
634         return run_command(&hook);
637 static void print_summary(const char *prefix, const unsigned char *sha1)
639         struct rev_info rev;
640         struct commit *commit;
642         commit = lookup_commit(sha1);
643         if (!commit)
644                 die("couldn't look up newly created commit\n");
645         if (!commit || parse_commit(commit))
646                 die("could not parse newly created commit");
648         init_revisions(&rev, prefix);
649         setup_revisions(0, NULL, &rev, NULL);
651         rev.abbrev = 0;
652         rev.diff = 1;
653         rev.diffopt.output_format =
654                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
656         rev.verbose_header = 1;
657         rev.show_root_diff = 1;
658         rev.commit_format = get_commit_format("format:%h: %s");
659         rev.always_show_header = 1;
661         printf("Created %scommit ", initial_commit ? "initial " : "");
663         log_tree_commit(&rev, commit);
664         printf("\n");
667 int git_commit_config(const char *k, const char *v)
669         if (!strcmp(k, "commit.template")) {
670                 template_file = xstrdup(v);
671                 return 0;
672         }
674         return git_status_config(k, v);
677 static const char commit_utf8_warn[] =
678 "Warning: commit message does not conform to UTF-8.\n"
679 "You may want to amend it after fixing the message, or set the config\n"
680 "variable i18n.commitencoding to the encoding your project uses.\n";
682 int cmd_commit(int argc, const char **argv, const char *prefix)
684         int header_len;
685         struct strbuf sb;
686         const char *index_file, *reflog_msg;
687         char *nl, *p;
688         unsigned char commit_sha1[20];
689         struct ref_lock *ref_lock;
691         git_config(git_commit_config);
693         argc = parse_and_validate_options(argc, argv);
695         index_file = prepare_index(argv, prefix);
697         if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
698                 rollback_index_files();
699                 return 1;
700         }
702         if (!prepare_log_message(index_file, prefix) && !in_merge) {
703                 run_status(stdout, index_file, prefix);
704                 rollback_index_files();
705                 unlink(commit_editmsg);
706                 return 1;
707         }
709         /*
710          * Re-read the index as pre-commit hook could have updated it,
711          * and write it out as a tree.
712          */
713         discard_cache();
714         read_cache_from(index_file);
715         if (!active_cache_tree)
716                 active_cache_tree = cache_tree();
717         if (cache_tree_update(active_cache_tree,
718                               active_cache, active_nr, 0, 0) < 0) {
719                 rollback_index_files();
720                 die("Error building trees");
721         }
723         /*
724          * The commit object
725          */
726         strbuf_init(&sb, 0);
727         strbuf_addf(&sb, "tree %s\n",
728                     sha1_to_hex(active_cache_tree->sha1));
730         /* Determine parents */
731         if (initial_commit) {
732                 reflog_msg = "commit (initial)";
733         } else if (amend) {
734                 struct commit_list *c;
735                 struct commit *commit;
737                 reflog_msg = "commit (amend)";
738                 commit = lookup_commit(head_sha1);
739                 if (!commit || parse_commit(commit))
740                         die("could not parse HEAD commit");
742                 for (c = commit->parents; c; c = c->next)
743                         strbuf_addf(&sb, "parent %s\n",
744                                       sha1_to_hex(c->item->object.sha1));
745         } else if (in_merge) {
746                 struct strbuf m;
747                 FILE *fp;
749                 reflog_msg = "commit (merge)";
750                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
751                 strbuf_init(&m, 0);
752                 fp = fopen(git_path("MERGE_HEAD"), "r");
753                 if (fp == NULL)
754                         die("could not open %s for reading: %s",
755                             git_path("MERGE_HEAD"), strerror(errno));
756                 while (strbuf_getline(&m, fp, '\n') != EOF)
757                         strbuf_addf(&sb, "parent %s\n", m.buf);
758                 fclose(fp);
759                 strbuf_release(&m);
760         } else {
761                 reflog_msg = "commit";
762                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
763         }
765         determine_author_info(&sb);
766         strbuf_addf(&sb, "committer %s\n", git_committer_info(1));
767         if (!is_encoding_utf8(git_commit_encoding))
768                 strbuf_addf(&sb, "encoding %s\n", git_commit_encoding);
769         strbuf_addch(&sb, '\n');
771         /* Get the commit message and validate it */
772         header_len = sb.len;
773         if (!no_edit) {
774                 char index[PATH_MAX];
775                 const char *env[2] = { index, NULL };
776                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
777                 launch_editor(git_path(commit_editmsg), &sb, env);
778         } else if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
779                 rollback_index_files();
780                 die("could not read commit message\n");
781         }
782         if (run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
783                 rollback_index_files();
784                 exit(1);
785         }
787         /* Truncate the message just before the diff, if any. */
788         p = strstr(sb.buf, "\ndiff --git a/");
789         if (p != NULL)
790                 strbuf_setlen(&sb, p - sb.buf + 1);
792         stripspace(&sb, 1);
793         if (sb.len < header_len || message_is_empty(&sb, header_len)) {
794                 rollback_index_files();
795                 die("* no commit message?  aborting commit.");
796         }
797         strbuf_addch(&sb, '\0');
798         if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))
799                 fprintf(stderr, commit_utf8_warn);
801         if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
802                 rollback_index_files();
803                 die("failed to write commit object");
804         }
806         ref_lock = lock_any_ref_for_update("HEAD",
807                                            initial_commit ? NULL : head_sha1,
808                                            0);
810         nl = strchr(sb.buf + header_len, '\n');
811         if (nl)
812                 strbuf_setlen(&sb, nl + 1 - sb.buf);
813         else
814                 strbuf_addch(&sb, '\n');
815         strbuf_remove(&sb, 0, header_len);
816         strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
817         strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
819         if (!ref_lock) {
820                 rollback_index_files();
821                 die("cannot lock HEAD ref");
822         }
823         if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
824                 rollback_index_files();
825                 die("cannot update HEAD ref");
826         }
828         unlink(git_path("MERGE_HEAD"));
829         unlink(git_path("MERGE_MSG"));
831         commit_index_files();
833         rerere();
834         run_hook(get_index_file(), "post-commit", NULL);
835         if (!quiet)
836                 print_summary(prefix, commit_sha1);
838         return 0;