builtin-commit: make summary output consistent with status
[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 const char * const builtin_status_usage[] = {
31         "git-status [options] [--] <filepattern>...",
32         NULL
33 };
34
35 static unsigned char head_sha1[20], merge_head_sha1[20];
36 static char *use_message_buffer;
37 static const char commit_editmsg[] = "COMMIT_EDITMSG";
38 static struct lock_file index_lock; /* real index */
39 static struct lock_file false_lock; /* used only for partial commits */
40 static enum {
41         COMMIT_AS_IS = 1,
42         COMMIT_NORMAL,
43         COMMIT_PARTIAL,
44 } commit_style;
45
46 static char *logfile, *force_author, *template_file;
47 static char *edit_message, *use_message;
48 static int all, edit_flag, also, interactive, only, amend, signoff;
49 static int quiet, verbose, untracked_files, no_verify, allow_empty;
50
51 static int no_edit, initial_commit, in_merge;
52 const char *only_include_assumed;
53 struct strbuf message;
54
55 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
56 {
57         struct strbuf *buf = opt->value;
58         if (unset)
59                 strbuf_setlen(buf, 0);
60         else {
61                 strbuf_addstr(buf, arg);
62                 strbuf_addch(buf, '\n');
63                 strbuf_addch(buf, '\n');
64         }
65         return 0;
66 }
67
68 static struct option builtin_commit_options[] = {
69         OPT__QUIET(&quiet),
70         OPT__VERBOSE(&verbose),
71         OPT_GROUP("Commit message options"),
72
73         OPT_STRING('F', "file", &logfile, "FILE", "read log from file"),
74         OPT_STRING(0, "author", &force_author, "AUTHOR", "override author for commit"),
75         OPT_CALLBACK('m', "message", &message, "MESSAGE", "specify commit message", opt_parse_m),
76         OPT_STRING('c', "reedit-message", &edit_message, "COMMIT", "reuse and edit message from specified commit "),
77         OPT_STRING('C', "reuse-message", &use_message, "COMMIT", "reuse message from specified commit"),
78         OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by: header"),
79         OPT_STRING('t', "template", &template_file, "FILE", "use specified template file"),
80         OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
81
82         OPT_GROUP("Commit contents options"),
83         OPT_BOOLEAN('a', "all", &all, "commit all changed files"),
84         OPT_BOOLEAN('i', "include", &also, "add specified files to index for commit"),
85         OPT_BOOLEAN(0, "interactive", &interactive, "interactively add files"),
86         OPT_BOOLEAN('o', "only", &only, ""),
87         OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
88         OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
89         OPT_BOOLEAN(0, "untracked-files", &untracked_files, "show all untracked files"),
90         OPT_BOOLEAN(0, "allow-empty", &allow_empty, "ok to record an empty change"),
91
92         OPT_END()
93 };
94
95 static void rollback_index_files(void)
96 {
97         switch (commit_style) {
98         case COMMIT_AS_IS:
99                 break; /* nothing to do */
100         case COMMIT_NORMAL:
101                 rollback_lock_file(&index_lock);
102                 break;
103         case COMMIT_PARTIAL:
104                 rollback_lock_file(&index_lock);
105                 rollback_lock_file(&false_lock);
106                 break;
107         }
108 }
109
110 static void commit_index_files(void)
111 {
112         switch (commit_style) {
113         case COMMIT_AS_IS:
114                 break; /* nothing to do */
115         case COMMIT_NORMAL:
116                 commit_lock_file(&index_lock);
117                 break;
118         case COMMIT_PARTIAL:
119                 commit_lock_file(&index_lock);
120                 rollback_lock_file(&false_lock);
121                 break;
122         }
123 }
124
125 /*
126  * Take a union of paths in the index and the named tree (typically, "HEAD"),
127  * and return the paths that match the given pattern in list.
128  */
129 static int list_paths(struct path_list *list, const char *with_tree,
130                       const char *prefix, const char **pattern)
131 {
132         int i;
133         char *m;
134
135         for (i = 0; pattern[i]; i++)
136                 ;
137         m = xcalloc(1, i);
138
139         if (with_tree)
140                 overlay_tree_on_cache(with_tree, prefix);
141
142         for (i = 0; i < active_nr; i++) {
143                 struct cache_entry *ce = active_cache[i];
144                 if (ce->ce_flags & htons(CE_UPDATE))
145                         continue;
146                 if (!pathspec_match(pattern, m, ce->name, 0))
147                         continue;
148                 path_list_insert(ce->name, list);
149         }
150
151         return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
152 }
153
154 static void add_remove_files(struct path_list *list)
155 {
156         int i;
157         for (i = 0; i < list->nr; i++) {
158                 struct path_list_item *p = &(list->items[i]);
159                 if (file_exists(p->path))
160                         add_file_to_cache(p->path, 0);
161                 else
162                         remove_file_from_cache(p->path);
163         }
164 }
165
166 static char *prepare_index(int argc, const char **argv, const char *prefix)
167 {
168         int fd;
169         struct tree *tree;
170         struct path_list partial;
171         const char **pathspec = NULL;
172
173         if (interactive) {
174                 interactive_add(argc, argv, prefix);
175                 commit_style = COMMIT_AS_IS;
176                 return get_index_file();
177         }
178
179         if (read_cache() < 0)
180                 die("index file corrupt");
181
182         if (*argv)
183                 pathspec = get_pathspec(prefix, argv);
184
185         /*
186          * Non partial, non as-is commit.
187          *
188          * (1) get the real index;
189          * (2) update the_index as necessary;
190          * (3) write the_index out to the real index (still locked);
191          * (4) return the name of the locked index file.
192          *
193          * The caller should run hooks on the locked real index, and
194          * (A) if all goes well, commit the real index;
195          * (B) on failure, rollback the real index.
196          */
197         if (all || (also && pathspec && *pathspec)) {
198                 int fd = hold_locked_index(&index_lock, 1);
199                 add_files_to_cache(0, also ? prefix : NULL, pathspec);
200                 refresh_cache(REFRESH_QUIET);
201                 if (write_cache(fd, active_cache, active_nr) || close(fd))
202                         die("unable to write new_index file");
203                 commit_style = COMMIT_NORMAL;
204                 return index_lock.filename;
205         }
206
207         /*
208          * As-is commit.
209          *
210          * (1) return the name of the real index file.
211          *
212          * The caller should run hooks on the real index, and run
213          * hooks on the real index, and create commit from the_index.
214          * We still need to refresh the index here.
215          */
216         if (!pathspec || !*pathspec) {
217                 fd = hold_locked_index(&index_lock, 1);
218                 refresh_cache(REFRESH_QUIET);
219                 if (write_cache(fd, active_cache, active_nr) ||
220                     close(fd) || commit_locked_index(&index_lock))
221                         die("unable to write new_index file");
222                 commit_style = COMMIT_AS_IS;
223                 return get_index_file();
224         }
225
226         /*
227          * A partial commit.
228          *
229          * (0) find the set of affected paths;
230          * (1) get lock on the real index file;
231          * (2) update the_index with the given paths;
232          * (3) write the_index out to the real index (still locked);
233          * (4) get lock on the false index file;
234          * (5) reset the_index from HEAD;
235          * (6) update the_index the same way as (2);
236          * (7) write the_index out to the false index file;
237          * (8) return the name of the false index file (still locked);
238          *
239          * The caller should run hooks on the locked false index, and
240          * create commit from it.  Then
241          * (A) if all goes well, commit the real index;
242          * (B) on failure, rollback the real index;
243          * In either case, rollback the false index.
244          */
245         commit_style = COMMIT_PARTIAL;
246
247         if (file_exists(git_path("MERGE_HEAD")))
248                 die("cannot do a partial commit during a merge.");
249
250         memset(&partial, 0, sizeof(partial));
251         partial.strdup_paths = 1;
252         if (list_paths(&partial, initial_commit ? NULL : "HEAD", prefix, pathspec))
253                 exit(1);
254
255         discard_cache();
256         if (read_cache() < 0)
257                 die("cannot read the index");
258
259         fd = hold_locked_index(&index_lock, 1);
260         add_remove_files(&partial);
261         refresh_cache(REFRESH_QUIET);
262         if (write_cache(fd, active_cache, active_nr) || close(fd))
263                 die("unable to write new_index file");
264
265         fd = hold_lock_file_for_update(&false_lock,
266                                        git_path("next-index-%d", getpid()), 1);
267         discard_cache();
268         if (!initial_commit) {
269                 tree = parse_tree_indirect(head_sha1);
270                 if (!tree)
271                         die("failed to unpack HEAD tree object");
272                 if (read_tree(tree, 0, NULL))
273                         die("failed to read HEAD tree object");
274         }
275         add_remove_files(&partial);
276         refresh_cache(REFRESH_QUIET);
277
278         if (write_cache(fd, active_cache, active_nr) || close(fd))
279                 die("unable to write temporary index file");
280         return false_lock.filename;
281 }
282
283 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn)
284 {
285         struct wt_status s;
286
287         wt_status_prepare(&s);
288         if (wt_status_relative_paths)
289                 s.prefix = prefix;
290
291         if (amend) {
292                 s.amend = 1;
293                 s.reference = "HEAD^1";
294         }
295         s.verbose = verbose;
296         s.untracked = untracked_files;
297         s.index_file = index_file;
298         s.fp = fp;
299         s.nowarn = nowarn;
300
301         wt_status_print(&s);
302
303         return s.commitable;
304 }
305
306 static const char sign_off_header[] = "Signed-off-by: ";
307
308 static int prepare_log_message(const char *index_file, const char *prefix)
309 {
310         struct stat statbuf;
311         int commitable, saved_color_setting;
312         struct strbuf sb;
313         char *buffer;
314         FILE *fp;
315
316         strbuf_init(&sb, 0);
317         if (message.len) {
318                 strbuf_addbuf(&sb, &message);
319         } else if (logfile && !strcmp(logfile, "-")) {
320                 if (isatty(0))
321                         fprintf(stderr, "(reading log message from standard input)\n");
322                 if (strbuf_read(&sb, 0, 0) < 0)
323                         die("could not read log from standard input");
324         } else if (logfile) {
325                 if (strbuf_read_file(&sb, logfile, 0) < 0)
326                         die("could not read log file '%s': %s",
327                             logfile, strerror(errno));
328         } else if (use_message) {
329                 buffer = strstr(use_message_buffer, "\n\n");
330                 if (!buffer || buffer[2] == '\0')
331                         die("commit has empty message");
332                 strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
333         } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
334                 if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
335                         die("could not read MERGE_MSG: %s", strerror(errno));
336         } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
337                 if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
338                         die("could not read SQUASH_MSG: %s", strerror(errno));
339         } else if (template_file && !stat(template_file, &statbuf)) {
340                 if (strbuf_read_file(&sb, template_file, 0) < 0)
341                         die("could not read %s: %s",
342                             template_file, strerror(errno));
343         }
344
345         fp = fopen(git_path(commit_editmsg), "w");
346         if (fp == NULL)
347                 die("could not open %s", git_path(commit_editmsg));
348
349         stripspace(&sb, 0);
350
351         if (signoff) {
352                 struct strbuf sob;
353                 int i;
354
355                 strbuf_init(&sob, 0);
356                 strbuf_addstr(&sob, sign_off_header);
357                 strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
358                                              getenv("GIT_COMMITTER_EMAIL")));
359                 strbuf_addch(&sob, '\n');
360                 for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
361                         ; /* do nothing */
362                 if (prefixcmp(sb.buf + i, sob.buf)) {
363                         if (prefixcmp(sb.buf + i, sign_off_header))
364                                 strbuf_addch(&sb, '\n');
365                         strbuf_addbuf(&sb, &sob);
366                 }
367                 strbuf_release(&sob);
368         }
369
370         if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
371                 die("could not write commit template: %s", strerror(errno));
372
373         strbuf_release(&sb);
374
375         if (no_edit) {
376                 struct rev_info rev;
377                 unsigned char sha1[40];
378
379                 fclose(fp);
380
381                 if (!active_nr && read_cache() < 0)
382                         die("Cannot read index");
383
384                 if (get_sha1("HEAD", sha1) != 0)
385                         return !!active_nr;
386
387                 init_revisions(&rev, "");
388                 rev.abbrev = 0;
389                 setup_revisions(0, NULL, &rev, "HEAD");
390                 DIFF_OPT_SET(&rev.diffopt, QUIET);
391                 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
392                 run_diff_index(&rev, 1 /* cached */);
393
394                 return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
395         }
396
397         if (in_merge && !no_edit)
398                 fprintf(fp,
399                         "#\n"
400                         "# It looks like you may be committing a MERGE.\n"
401                         "# If this is not correct, please remove the file\n"
402                         "#      %s\n"
403                         "# and try again.\n"
404                         "#\n",
405                         git_path("MERGE_HEAD"));
406
407         fprintf(fp,
408                 "\n"
409                 "# Please enter the commit message for your changes.\n"
410                 "# (Comment lines starting with '#' will not be included)\n");
411         if (only_include_assumed)
412                 fprintf(fp, "# %s\n", only_include_assumed);
413
414         saved_color_setting = wt_status_use_color;
415         wt_status_use_color = 0;
416         commitable = run_status(fp, index_file, prefix, 1);
417         wt_status_use_color = saved_color_setting;
418
419         fclose(fp);
420
421         return commitable;
422 }
423
424 /*
425  * Find out if the message starting at position 'start' in the strbuf
426  * contains only whitespace and Signed-off-by lines.
427  */
428 static int message_is_empty(struct strbuf *sb, int start)
429 {
430         struct strbuf tmpl;
431         const char *nl;
432         int eol, i;
433
434         /* See if the template is just a prefix of the message. */
435         strbuf_init(&tmpl, 0);
436         if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
437                 stripspace(&tmpl, 1);
438                 if (start + tmpl.len <= sb->len &&
439                     memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
440                         start += tmpl.len;
441         }
442         strbuf_release(&tmpl);
443
444         /* Check if the rest is just whitespace and Signed-of-by's. */
445         for (i = start; i < sb->len; i++) {
446                 nl = memchr(sb->buf + i, '\n', sb->len - i);
447                 if (nl)
448                         eol = nl - sb->buf;
449                 else
450                         eol = sb->len;
451
452                 if (strlen(sign_off_header) <= eol - i &&
453                     !prefixcmp(sb->buf + i, sign_off_header)) {
454                         i = eol;
455                         continue;
456                 }
457                 while (i < eol)
458                         if (!isspace(sb->buf[i++]))
459                                 return 0;
460         }
461
462         return 1;
463 }
464
465 static void determine_author_info(struct strbuf *sb)
466 {
467         char *name, *email, *date;
468
469         name = getenv("GIT_AUTHOR_NAME");
470         email = getenv("GIT_AUTHOR_EMAIL");
471         date = getenv("GIT_AUTHOR_DATE");
472
473         if (use_message) {
474                 const char *a, *lb, *rb, *eol;
475
476                 a = strstr(use_message_buffer, "\nauthor ");
477                 if (!a)
478                         die("invalid commit: %s", use_message);
479
480                 lb = strstr(a + 8, " <");
481                 rb = strstr(a + 8, "> ");
482                 eol = strchr(a + 8, '\n');
483                 if (!lb || !rb || !eol)
484                         die("invalid commit: %s", use_message);
485
486                 name = xstrndup(a + 8, lb - (a + 8));
487                 email = xstrndup(lb + 2, rb - (lb + 2));
488                 date = xstrndup(rb + 2, eol - (rb + 2));
489         }
490
491         if (force_author) {
492                 const char *lb = strstr(force_author, " <");
493                 const char *rb = strchr(force_author, '>');
494
495                 if (!lb || !rb)
496                         die("malformed --author parameter");
497                 name = xstrndup(force_author, lb - force_author);
498                 email = xstrndup(lb + 2, rb - (lb + 2));
499         }
500
501         strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, IDENT_ERROR_ON_NO_NAME));
502 }
503
504 static int parse_and_validate_options(int argc, const char *argv[],
505                                       const char * const usage[])
506 {
507         int f = 0;
508
509         argc = parse_options(argc, argv, builtin_commit_options, usage, 0);
510
511         if (logfile || message.len || use_message)
512                 no_edit = 1;
513         if (edit_flag)
514                 no_edit = 0;
515
516         if (get_sha1("HEAD", head_sha1))
517                 initial_commit = 1;
518
519         if (!get_sha1("MERGE_HEAD", merge_head_sha1))
520                 in_merge = 1;
521
522         /* Sanity check options */
523         if (amend && initial_commit)
524                 die("You have nothing to amend.");
525         if (amend && in_merge)
526                 die("You are in the middle of a merge -- cannot amend.");
527
528         if (use_message)
529                 f++;
530         if (edit_message)
531                 f++;
532         if (logfile)
533                 f++;
534         if (f > 1)
535                 die("Only one of -c/-C/-F can be used.");
536         if (message.len && f > 0)
537                 die("Option -m cannot be combined with -c/-C/-F.");
538         if (edit_message)
539                 use_message = edit_message;
540         if (amend && !use_message)
541                 use_message = "HEAD";
542         if (use_message) {
543                 unsigned char sha1[20];
544                 static char utf8[] = "UTF-8";
545                 const char *out_enc;
546                 char *enc, *end;
547                 struct commit *commit;
548
549                 if (get_sha1(use_message, sha1))
550                         die("could not lookup commit %s", use_message);
551                 commit = lookup_commit(sha1);
552                 if (!commit || parse_commit(commit))
553                         die("could not parse commit %s", use_message);
554
555                 enc = strstr(commit->buffer, "\nencoding");
556                 if (enc) {
557                         end = strchr(enc + 10, '\n');
558                         enc = xstrndup(enc + 10, end - (enc + 10));
559                 } else {
560                         enc = utf8;
561                 }
562                 out_enc = git_commit_encoding ? git_commit_encoding : utf8;
563
564                 if (strcmp(out_enc, enc))
565                         use_message_buffer =
566                                 reencode_string(commit->buffer, out_enc, enc);
567
568                 /*
569                  * If we failed to reencode the buffer, just copy it
570                  * byte for byte so the user can try to fix it up.
571                  * This also handles the case where input and output
572                  * encodings are identical.
573                  */
574                 if (use_message_buffer == NULL)
575                         use_message_buffer = xstrdup(commit->buffer);
576                 if (enc != utf8)
577                         free(enc);
578         }
579
580         if (!!also + !!only + !!all + !!interactive > 1)
581                 die("Only one of --include/--only/--all/--interactive can be used.");
582         if (argc == 0 && (also || (only && !amend)))
583                 die("No paths with --include/--only does not make sense.");
584         if (argc == 0 && only && amend)
585                 only_include_assumed = "Clever... amending the last one with dirty index.";
586         if (argc > 0 && !also && !only) {
587                 only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
588                 also = 0;
589         }
590
591         if (all && argc > 0)
592                 die("Paths with -a does not make sense.");
593         else if (interactive && argc > 0)
594                 die("Paths with --interactive does not make sense.");
595
596         return argc;
597 }
598
599 int cmd_status(int argc, const char **argv, const char *prefix)
600 {
601         const char *index_file;
602         int commitable;
603
604         git_config(git_status_config);
605
606         argc = parse_and_validate_options(argc, argv, builtin_status_usage);
607
608         index_file = prepare_index(argc, argv, prefix);
609
610         commitable = run_status(stdout, index_file, prefix, 0);
611
612         rollback_index_files();
613
614         return commitable ? 0 : 1;
615 }
616
617 static int run_hook(const char *index_file, const char *name, const char *arg)
618 {
619         struct child_process hook;
620         const char *argv[3], *env[2];
621         char index[PATH_MAX];
622
623         argv[0] = git_path("hooks/%s", name);
624         argv[1] = arg;
625         argv[2] = NULL;
626         snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
627         env[0] = index;
628         env[1] = NULL;
629
630         if (access(argv[0], X_OK) < 0)
631                 return 0;
632
633         memset(&hook, 0, sizeof(hook));
634         hook.argv = argv;
635         hook.no_stdin = 1;
636         hook.stdout_to_stderr = 1;
637         hook.env = env;
638
639         return run_command(&hook);
640 }
641
642 static void print_summary(const char *prefix, const unsigned char *sha1)
643 {
644         struct rev_info rev;
645         struct commit *commit;
646
647         commit = lookup_commit(sha1);
648         if (!commit)
649                 die("couldn't look up newly created commit");
650         if (!commit || parse_commit(commit))
651                 die("could not parse newly created commit");
652
653         init_revisions(&rev, prefix);
654         setup_revisions(0, NULL, &rev, NULL);
655
656         rev.abbrev = 0;
657         rev.diff = 1;
658         rev.diffopt.output_format =
659                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
660
661         rev.verbose_header = 1;
662         rev.show_root_diff = 1;
663         rev.commit_format = get_commit_format("format:%h: %s");
664         rev.always_show_header = 0;
665         rev.diffopt.detect_rename = 1;
666         rev.diffopt.rename_limit = 100;
667         rev.diffopt.break_opt = 0;
668         diff_setup_done(&rev.diffopt);
669
670         printf("Created %scommit ", initial_commit ? "initial " : "");
671
672         if (!log_tree_commit(&rev, commit)) {
673                 struct strbuf buf = STRBUF_INIT;
674                 format_commit_message(commit, "%h: %s", &buf);
675                 printf("%s\n", buf.buf);
676                 strbuf_release(&buf);
677         }
678 }
679
680 int git_commit_config(const char *k, const char *v)
681 {
682         if (!strcmp(k, "commit.template")) {
683                 template_file = xstrdup(v);
684                 return 0;
685         }
686
687         return git_status_config(k, v);
688 }
689
690 static int is_a_merge(const unsigned char *sha1)
691 {
692         struct commit *commit = lookup_commit(sha1);
693         if (!commit || parse_commit(commit))
694                 die("could not parse HEAD commit");
695         return !!(commit->parents && commit->parents->next);
696 }
697
698 static const char commit_utf8_warn[] =
699 "Warning: commit message does not conform to UTF-8.\n"
700 "You may want to amend it after fixing the message, or set the config\n"
701 "variable i18n.commitencoding to the encoding your project uses.\n";
702
703 int cmd_commit(int argc, const char **argv, const char *prefix)
704 {
705         int header_len;
706         struct strbuf sb;
707         const char *index_file, *reflog_msg;
708         char *nl, *p;
709         unsigned char commit_sha1[20];
710         struct ref_lock *ref_lock;
711
712         git_config(git_commit_config);
713
714         argc = parse_and_validate_options(argc, argv, builtin_commit_usage);
715
716         index_file = prepare_index(argc, argv, prefix);
717
718         if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
719                 rollback_index_files();
720                 return 1;
721         }
722
723         if (!prepare_log_message(index_file, prefix) && !in_merge &&
724             !allow_empty && !(amend && is_a_merge(head_sha1))) {
725                 run_status(stdout, index_file, prefix, 0);
726                 rollback_index_files();
727                 unlink(commit_editmsg);
728                 return 1;
729         }
730
731         /*
732          * Re-read the index as pre-commit hook could have updated it,
733          * and write it out as a tree.
734          */
735         discard_cache();
736         read_cache_from(index_file);
737         if (!active_cache_tree)
738                 active_cache_tree = cache_tree();
739         if (cache_tree_update(active_cache_tree,
740                               active_cache, active_nr, 0, 0) < 0) {
741                 rollback_index_files();
742                 die("Error building trees");
743         }
744
745         /*
746          * The commit object
747          */
748         strbuf_init(&sb, 0);
749         strbuf_addf(&sb, "tree %s\n",
750                     sha1_to_hex(active_cache_tree->sha1));
751
752         /* Determine parents */
753         if (initial_commit) {
754                 reflog_msg = "commit (initial)";
755         } else if (amend) {
756                 struct commit_list *c;
757                 struct commit *commit;
758
759                 reflog_msg = "commit (amend)";
760                 commit = lookup_commit(head_sha1);
761                 if (!commit || parse_commit(commit))
762                         die("could not parse HEAD commit");
763
764                 for (c = commit->parents; c; c = c->next)
765                         strbuf_addf(&sb, "parent %s\n",
766                                       sha1_to_hex(c->item->object.sha1));
767         } else if (in_merge) {
768                 struct strbuf m;
769                 FILE *fp;
770
771                 reflog_msg = "commit (merge)";
772                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
773                 strbuf_init(&m, 0);
774                 fp = fopen(git_path("MERGE_HEAD"), "r");
775                 if (fp == NULL)
776                         die("could not open %s for reading: %s",
777                             git_path("MERGE_HEAD"), strerror(errno));
778                 while (strbuf_getline(&m, fp, '\n') != EOF)
779                         strbuf_addf(&sb, "parent %s\n", m.buf);
780                 fclose(fp);
781                 strbuf_release(&m);
782         } else {
783                 reflog_msg = "commit";
784                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
785         }
786
787         determine_author_info(&sb);
788         strbuf_addf(&sb, "committer %s\n", git_committer_info(IDENT_ERROR_ON_NO_NAME));
789         if (!is_encoding_utf8(git_commit_encoding))
790                 strbuf_addf(&sb, "encoding %s\n", git_commit_encoding);
791         strbuf_addch(&sb, '\n');
792
793         /* Get the commit message and validate it */
794         header_len = sb.len;
795         if (!no_edit) {
796                 char index[PATH_MAX];
797                 const char *env[2] = { index, NULL };
798                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
799                 launch_editor(git_path(commit_editmsg), NULL, env);
800         }
801         if (!no_verify &&
802             run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
803                 rollback_index_files();
804                 exit(1);
805         }
806         if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
807                 rollback_index_files();
808                 die("could not read commit message");
809         }
810
811         /* Truncate the message just before the diff, if any. */
812         p = strstr(sb.buf, "\ndiff --git a/");
813         if (p != NULL)
814                 strbuf_setlen(&sb, p - sb.buf + 1);
815
816         stripspace(&sb, 1);
817         if (sb.len < header_len || message_is_empty(&sb, header_len)) {
818                 rollback_index_files();
819                 die("no commit message?  aborting commit.");
820         }
821         strbuf_addch(&sb, '\0');
822         if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))
823                 fprintf(stderr, commit_utf8_warn);
824
825         if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
826                 rollback_index_files();
827                 die("failed to write commit object");
828         }
829
830         ref_lock = lock_any_ref_for_update("HEAD",
831                                            initial_commit ? NULL : head_sha1,
832                                            0);
833
834         nl = strchr(sb.buf + header_len, '\n');
835         if (nl)
836                 strbuf_setlen(&sb, nl + 1 - sb.buf);
837         else
838                 strbuf_addch(&sb, '\n');
839         strbuf_remove(&sb, 0, header_len);
840         strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
841         strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
842
843         if (!ref_lock) {
844                 rollback_index_files();
845                 die("cannot lock HEAD ref");
846         }
847         if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
848                 rollback_index_files();
849                 die("cannot update HEAD ref");
850         }
851
852         unlink(git_path("MERGE_HEAD"));
853         unlink(git_path("MERGE_MSG"));
854
855         commit_index_files();
856
857         rerere();
858         run_hook(get_index_file(), "post-commit", NULL);
859         if (!quiet)
860                 print_summary(prefix, commit_sha1);
861
862         return 0;
863 }