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 "color.h"
  11 #include "dir.h"
  12 #include "builtin.h"
  13 #include "diff.h"
  14 #include "diffcore.h"
  15 #include "commit.h"
  16 #include "revision.h"
  17 #include "wt-status.h"
  18 #include "run-command.h"
  19 #include "refs.h"
  20 #include "log-tree.h"
  21 #include "strbuf.h"
  22 #include "utf8.h"
  23 #include "parse-options.h"
  24 #include "string-list.h"
  25 #include "rerere.h"
  26 #include "unpack-trees.h"
  27 #include "quote.h"
  28
  29 static const char * const builtin_commit_usage[] = {
  30         "git commit [options] [--] <filepattern>...",
  31         NULL
  32 };
  33
  34 static const char * const builtin_status_usage[] = {
  35         "git status [options] [--] <filepattern>...",
  36         NULL
  37 };
  38
  39 static const char implicit_ident_advice[] =
  40 "Your name and email address were configured automatically based\n"
  41 "on your username and hostname. Please check that they are accurate.\n"
  42 "You can suppress this message by setting them explicitly:\n"
  43 "\n"
  44 "    git config --global user.name \"Your Name\"\n"
  45 "    git config --global user.email you@example.com\n"
  46 "\n"
  47 "If the identity used for this commit is wrong, you can fix it with:\n"
  48 "\n"
  49 "    git commit --amend --author='Your Name <you@example.com>'\n";
  50
  51 static unsigned char head_sha1[20];
  52
  53 static char *use_message_buffer;
  54 static const char commit_editmsg[] = "COMMIT_EDITMSG";
  55 static struct lock_file index_lock; /* real index */
  56 static struct lock_file false_lock; /* used only for partial commits */
  57 static enum {
  58         COMMIT_AS_IS = 1,
  59         COMMIT_NORMAL,
  60         COMMIT_PARTIAL,
  61 } commit_style;
  62
  63 static const char *logfile, *force_author;
  64 static const char *template_file;
  65 static char *edit_message, *use_message;
  66 static char *author_name, *author_email, *author_date;
  67 static int all, edit_flag, also, interactive, only, amend, signoff;
  68 static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
  69 static int no_post_rewrite, allow_empty_message;
  70 static char *untracked_files_arg, *force_date;
  71 /*
  72  * The default commit message cleanup mode will remove the lines
  73  * beginning with # (shell comments) and leading and trailing
  74  * whitespaces (empty lines or containing only whitespaces)
  75  * if editor is used, and only the whitespaces if the message
  76  * is specified explicitly.
  77  */
  78 static enum {
  79         CLEANUP_SPACE,
  80         CLEANUP_NONE,
  81         CLEANUP_ALL,
  82 } cleanup_mode;
  83 static char *cleanup_arg;
  84
  85 static int use_editor = 1, initial_commit, in_merge, include_status = 1;
  86 static const char *only_include_assumed;
  87 static struct strbuf message;
  88
  89 static int null_termination;
  90 static enum {
  91         STATUS_FORMAT_LONG,
  92         STATUS_FORMAT_SHORT,
  93         STATUS_FORMAT_PORCELAIN,
  94 } status_format = STATUS_FORMAT_LONG;
  95
  96 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
  97 {
  98         struct strbuf *buf = opt->value;
  99         if (unset)
 100                 strbuf_setlen(buf, 0);
 101         else {
 102                 strbuf_addstr(buf, arg);
 103                 strbuf_addstr(buf, "\n\n");
 104         }
 105         return 0;
 106 }
 107
 108 static struct option builtin_commit_options[] = {
 109         OPT__QUIET(&quiet),
 110         OPT__VERBOSE(&verbose),
 111
 112         OPT_GROUP("Commit message options"),
 113         OPT_FILENAME('F', "file", &logfile, "read log from file"),
 114         OPT_STRING(0, "author", &force_author, "AUTHOR", "override author for commit"),
 115         OPT_STRING(0, "date", &force_date, "DATE", "override date for commit"),
 116         OPT_CALLBACK('m', "message", &message, "MESSAGE", "specify commit message", opt_parse_m),
 117         OPT_STRING('c', "reedit-message", &edit_message, "COMMIT", "reuse and edit message from specified commit"),
 118         OPT_STRING('C', "reuse-message", &use_message, "COMMIT", "reuse message from specified commit"),
 119         OPT_BOOLEAN(0, "reset-author", &renew_authorship, "the commit is authored by me now (used with -C-c/--amend)"),
 120         OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
 121         OPT_FILENAME('t', "template", &template_file, "use specified template file"),
 122         OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
 123         OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
 124         OPT_BOOLEAN(0, "status", &include_status, "include status in commit message template"),
 125         /* end commit message options */
 126
 127         OPT_GROUP("Commit contents options"),
 128         OPT_BOOLEAN('a', "all", &all, "commit all changed files"),
 129         OPT_BOOLEAN('i', "include", &also, "add specified files to index for commit"),
 130         OPT_BOOLEAN(0, "interactive", &interactive, "interactively add files"),
 131         OPT_BOOLEAN('o', "only", &only, "commit only specified files"),
 132         OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
 133         OPT_BOOLEAN(0, "dry-run", &dry_run, "show what would be committed"),
 134         OPT_SET_INT(0, "short", &status_format, "show status concisely",
 135                     STATUS_FORMAT_SHORT),
 136         OPT_SET_INT(0, "porcelain", &status_format,
 137                     "show porcelain output format", STATUS_FORMAT_PORCELAIN),
 138         OPT_BOOLEAN('z', "null", &null_termination,
 139                     "terminate entries with NUL"),
 140         OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
 141         OPT_BOOLEAN(0, "no-post-rewrite", &no_post_rewrite, "bypass post-rewrite hook"),
 142         { OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, "mode", "show untracked files, optional modes: all, normal, no. (Default: all)", PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 143         /* end commit contents options */
 144
 145         { OPTION_BOOLEAN, 0, "allow-empty", &allow_empty, NULL,
 146           "ok to record an empty change",
 147           PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
 148         { OPTION_BOOLEAN, 0, "allow-empty-message", &allow_empty_message, NULL,
 149           "ok to record a change with an empty message",
 150           PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
 151
 152         OPT_END()
 153 };
 154
 155 static void rollback_index_files(void)
 156 {
 157         switch (commit_style) {
 158         case COMMIT_AS_IS:
 159                 break; /* nothing to do */
 160         case COMMIT_NORMAL:
 161                 rollback_lock_file(&index_lock);
 162                 break;
 163         case COMMIT_PARTIAL:
 164                 rollback_lock_file(&index_lock);
 165                 rollback_lock_file(&false_lock);
 166                 break;
 167         }
 168 }
 169
 170 static int commit_index_files(void)
 171 {
 172         int err = 0;
 173
 174         switch (commit_style) {
 175         case COMMIT_AS_IS:
 176                 break; /* nothing to do */
 177         case COMMIT_NORMAL:
 178                 err = commit_lock_file(&index_lock);
 179                 break;
 180         case COMMIT_PARTIAL:
 181                 err = commit_lock_file(&index_lock);
 182                 rollback_lock_file(&false_lock);
 183                 break;
 184         }
 185
 186         return err;
 187 }
 188
 189 /*
 190  * Take a union of paths in the index and the named tree (typically, "HEAD"),
 191  * and return the paths that match the given pattern in list.
 192  */
 193 static int list_paths(struct string_list *list, const char *with_tree,
 194                       const char *prefix, const char **pattern)
 195 {
 196         int i;
 197         char *m;
 198
 199         for (i = 0; pattern[i]; i++)
 200                 ;
 201         m = xcalloc(1, i);
 202
 203         if (with_tree)
 204                 overlay_tree_on_cache(with_tree, prefix);
 205
 206         for (i = 0; i < active_nr; i++) {
 207                 struct cache_entry *ce = active_cache[i];
 208                 struct string_list_item *item;
 209
 210                 if (ce->ce_flags & CE_UPDATE)
 211                         continue;
 212                 if (!match_pathspec(pattern, ce->name, ce_namelen(ce), 0, m))
 213                         continue;
 214                 item = string_list_insert(ce->name, list);
 215                 if (ce_skip_worktree(ce))
 216                         item->util = item; /* better a valid pointer than a fake one */
 217         }
 218
 219         return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
 220 }
 221
 222 static void add_remove_files(struct string_list *list)
 223 {
 224         int i;
 225         for (i = 0; i < list->nr; i++) {
 226                 struct stat st;
 227                 struct string_list_item *p = &(list->items[i]);
 228
 229                 /* p->util is skip-worktree */
 230                 if (p->util)
 231                         continue;
 232
 233                 if (!lstat(p->string, &st)) {
 234                         if (add_to_cache(p->string, &st, 0))
 235                                 die("updating files failed");
 236                 } else
 237                         remove_file_from_cache(p->string);
 238         }
 239 }
 240
 241 static void create_base_index(void)
 242 {
 243         struct tree *tree;
 244         struct unpack_trees_options opts;
 245         struct tree_desc t;
 246
 247         if (initial_commit) {
 248                 discard_cache();
 249                 return;
 250         }
 251
 252         memset(&opts, 0, sizeof(opts));
 253         opts.head_idx = 1;
 254         opts.index_only = 1;
 255         opts.merge = 1;
 256         opts.src_index = &the_index;
 257         opts.dst_index = &the_index;
 258
 259         opts.fn = oneway_merge;
 260         tree = parse_tree_indirect(head_sha1);
 261         if (!tree)
 262                 die("failed to unpack HEAD tree object");
 263         parse_tree(tree);
 264         init_tree_desc(&t, tree->buffer, tree->size);
 265         if (unpack_trees(1, &t, &opts))
 266                 exit(128); /* We've already reported the error, finish dying */
 267 }
 268
 269 static void refresh_cache_or_die(int refresh_flags)
 270 {
 271         /*
 272          * refresh_flags contains REFRESH_QUIET, so the only errors
 273          * are for unmerged entries.
 274          */
 275         if (refresh_cache(refresh_flags | REFRESH_IN_PORCELAIN))
 276                 die_resolve_conflict("commit");
 277 }
 278
 279 static char *prepare_index(int argc, const char **argv, const char *prefix, int is_status)
 280 {
 281         int fd;
 282         struct string_list partial;
 283         const char **pathspec = NULL;
 284         int refresh_flags = REFRESH_QUIET;
 285
 286         if (is_status)
 287                 refresh_flags |= REFRESH_UNMERGED;
 288         if (interactive) {
 289                 if (interactive_add(argc, argv, prefix) != 0)
 290                         die("interactive add failed");
 291                 if (read_cache_preload(NULL) < 0)
 292                         die("index file corrupt");
 293                 commit_style = COMMIT_AS_IS;
 294                 return get_index_file();
 295         }
 296
 297         if (*argv)
 298                 pathspec = get_pathspec(prefix, argv);
 299
 300         if (read_cache_preload(pathspec) < 0)
 301                 die("index file corrupt");
 302
 303         /*
 304          * Non partial, non as-is commit.
 305          *
 306          * (1) get the real index;
 307          * (2) update the_index as necessary;
 308          * (3) write the_index out to the real index (still locked);
 309          * (4) return the name of the locked index file.
 310          *
 311          * The caller should run hooks on the locked real index, and
 312          * (A) if all goes well, commit the real index;
 313          * (B) on failure, rollback the real index.
 314          */
 315         if (all || (also && pathspec && *pathspec)) {
 316                 fd = hold_locked_index(&index_lock, 1);
 317                 add_files_to_cache(also ? prefix : NULL, pathspec, 0);
 318                 refresh_cache_or_die(refresh_flags);
 319                 if (write_cache(fd, active_cache, active_nr) ||
 320                     close_lock_file(&index_lock))
 321                         die("unable to write new_index file");
 322                 commit_style = COMMIT_NORMAL;
 323                 return index_lock.filename;
 324         }
 325
 326         /*
 327          * As-is commit.
 328          *
 329          * (1) return the name of the real index file.
 330          *
 331          * The caller should run hooks on the real index,
 332          * and create commit from the_index.
 333          * We still need to refresh the index here.
 334          */
 335         if (!pathspec || !*pathspec) {
 336                 fd = hold_locked_index(&index_lock, 1);
 337                 refresh_cache_or_die(refresh_flags);
 338                 if (write_cache(fd, active_cache, active_nr) ||
 339                     commit_locked_index(&index_lock))
 340                         die("unable to write new_index file");
 341                 commit_style = COMMIT_AS_IS;
 342                 return get_index_file();
 343         }
 344
 345         /*
 346          * A partial commit.
 347          *
 348          * (0) find the set of affected paths;
 349          * (1) get lock on the real index file;
 350          * (2) update the_index with the given paths;
 351          * (3) write the_index out to the real index (still locked);
 352          * (4) get lock on the false index file;
 353          * (5) reset the_index from HEAD;
 354          * (6) update the_index the same way as (2);
 355          * (7) write the_index out to the false index file;
 356          * (8) return the name of the false index file (still locked);
 357          *
 358          * The caller should run hooks on the locked false index, and
 359          * create commit from it.  Then
 360          * (A) if all goes well, commit the real index;
 361          * (B) on failure, rollback the real index;
 362          * In either case, rollback the false index.
 363          */
 364         commit_style = COMMIT_PARTIAL;
 365
 366         if (in_merge)
 367                 die("cannot do a partial commit during a merge.");
 368
 369         memset(&partial, 0, sizeof(partial));
 370         partial.strdup_strings = 1;
 371         if (list_paths(&partial, initial_commit ? NULL : "HEAD", prefix, pathspec))
 372                 exit(1);
 373
 374         discard_cache();
 375         if (read_cache() < 0)
 376                 die("cannot read the index");
 377
 378         fd = hold_locked_index(&index_lock, 1);
 379         add_remove_files(&partial);
 380         refresh_cache(REFRESH_QUIET);
 381         if (write_cache(fd, active_cache, active_nr) ||
 382             close_lock_file(&index_lock))
 383                 die("unable to write new_index file");
 384
 385         fd = hold_lock_file_for_update(&false_lock,
 386                                        git_path("next-index-%"PRIuMAX,
 387                                                 (uintmax_t) getpid()),
 388                                        LOCK_DIE_ON_ERROR);
 389
 390         create_base_index();
 391         add_remove_files(&partial);
 392         refresh_cache(REFRESH_QUIET);
 393
 394         if (write_cache(fd, active_cache, active_nr) ||
 395             close_lock_file(&false_lock))
 396                 die("unable to write temporary index file");
 397
 398         discard_cache();
 399         read_cache_from(false_lock.filename);
 400
 401         return false_lock.filename;
 402 }
 403
 404 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
 405                       struct wt_status *s)
 406 {
 407         unsigned char sha1[20];
 408
 409         if (s->relative_paths)
 410                 s->prefix = prefix;
 411
 412         if (amend) {
 413                 s->amend = 1;
 414                 s->reference = "HEAD^1";
 415         }
 416         s->verbose = verbose;
 417         s->index_file = index_file;
 418         s->fp = fp;
 419         s->nowarn = nowarn;
 420         s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
 421
 422         wt_status_collect(s);
 423
 424         switch (status_format) {
 425         case STATUS_FORMAT_SHORT:
 426                 wt_shortstatus_print(s, null_termination);
 427                 break;
 428         case STATUS_FORMAT_PORCELAIN:
 429                 wt_porcelain_print(s, null_termination);
 430                 break;
 431         case STATUS_FORMAT_LONG:
 432                 wt_status_print(s);
 433                 break;
 434         }
 435
 436         return s->commitable;
 437 }
 438
 439 static int is_a_merge(const unsigned char *sha1)
 440 {
 441         struct commit *commit = lookup_commit(sha1);
 442         if (!commit || parse_commit(commit))
 443                 die("could not parse HEAD commit");
 444         return !!(commit->parents && commit->parents->next);
 445 }
 446
 447 static const char sign_off_header[] = "Signed-off-by: ";
 448
 449 static void determine_author_info(void)
 450 {
 451         char *name, *email, *date;
 452
 453         name = getenv("GIT_AUTHOR_NAME");
 454         email = getenv("GIT_AUTHOR_EMAIL");
 455         date = getenv("GIT_AUTHOR_DATE");
 456
 457         if (use_message && !renew_authorship) {
 458                 const char *a, *lb, *rb, *eol;
 459
 460                 a = strstr(use_message_buffer, "\nauthor ");
 461                 if (!a)
 462                         die("invalid commit: %s", use_message);
 463
 464                 lb = strstr(a + 8, " <");
 465                 rb = strstr(a + 8, "> ");
 466                 eol = strchr(a + 8, '\n');
 467                 if (!lb || !rb || !eol)
 468                         die("invalid commit: %s", use_message);
 469
 470                 name = xstrndup(a + 8, lb - (a + 8));
 471                 email = xstrndup(lb + 2, rb - (lb + 2));
 472                 date = xstrndup(rb + 2, eol - (rb + 2));
 473         }
 474
 475         if (force_author) {
 476                 const char *lb = strstr(force_author, " <");
 477                 const char *rb = strchr(force_author, '>');
 478
 479                 if (!lb || !rb)
 480                         die("malformed --author parameter");
 481                 name = xstrndup(force_author, lb - force_author);
 482                 email = xstrndup(lb + 2, rb - (lb + 2));
 483         }
 484
 485         if (force_date)
 486                 date = force_date;
 487
 488         author_name = name;
 489         author_email = email;
 490         author_date = date;
 491 }
 492
 493 static int ends_rfc2822_footer(struct strbuf *sb)
 494 {
 495         int ch;
 496         int hit = 0;
 497         int i, j, k;
 498         int len = sb->len;
 499         int first = 1;
 500         const char *buf = sb->buf;
 501
 502         for (i = len - 1; i > 0; i--) {
 503                 if (hit && buf[i] == '\n')
 504                         break;
 505                 hit = (buf[i] == '\n');
 506         }
 507
 508         while (i < len - 1 && buf[i] == '\n')
 509                 i++;
 510
 511         for (; i < len; i = k) {
 512                 for (k = i; k < len && buf[k] != '\n'; k++)
 513                         ; /* do nothing */
 514                 k++;
 515
 516                 if ((buf[k] == ' ' || buf[k] == '\t') && !first)
 517                         continue;
 518
 519                 first = 0;
 520
 521                 for (j = 0; i + j < len; j++) {
 522                         ch = buf[i + j];
 523                         if (ch == ':')
 524                                 break;
 525                         if (isalnum(ch) ||
 526                             (ch == '-'))
 527                                 continue;
 528                         return 0;
 529                 }
 530         }
 531         return 1;
 532 }
 533
 534 static int prepare_to_commit(const char *index_file, const char *prefix,
 535                              struct wt_status *s)
 536 {
 537         struct stat statbuf;
 538         int commitable, saved_color_setting;
 539         struct strbuf sb = STRBUF_INIT;
 540         char *buffer;
 541         FILE *fp;
 542         const char *hook_arg1 = NULL;
 543         const char *hook_arg2 = NULL;
 544         int ident_shown = 0;
 545
 546         if (!no_verify && run_hook(index_file, "pre-commit", NULL))
 547                 return 0;
 548
 549         if (message.len) {
 550                 strbuf_addbuf(&sb, &message);
 551                 hook_arg1 = "message";
 552         } else if (logfile && !strcmp(logfile, "-")) {
 553                 if (isatty(0))
 554                         fprintf(stderr, "(reading log message from standard input)\n");
 555                 if (strbuf_read(&sb, 0, 0) < 0)
 556                         die_errno("could not read log from standard input");
 557                 hook_arg1 = "message";
 558         } else if (logfile) {
 559                 if (strbuf_read_file(&sb, logfile, 0) < 0)
 560                         die_errno("could not read log file '%s'",
 561                                   logfile);
 562                 hook_arg1 = "message";
 563         } else if (use_message) {
 564                 buffer = strstr(use_message_buffer, "\n\n");
 565                 if (!buffer || buffer[2] == '\0')
 566                         die("commit has empty message");
 567                 strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
 568                 hook_arg1 = "commit";
 569                 hook_arg2 = use_message;
 570         } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
 571                 if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
 572                         die_errno("could not read MERGE_MSG");
 573                 hook_arg1 = "merge";
 574         } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
 575                 if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
 576                         die_errno("could not read SQUASH_MSG");
 577                 hook_arg1 = "squash";
 578         } else if (template_file && !stat(template_file, &statbuf)) {
 579                 if (strbuf_read_file(&sb, template_file, 0) < 0)
 580                         die_errno("could not read '%s'", template_file);
 581                 hook_arg1 = "template";
 582         }
 583
 584         /*
 585          * This final case does not modify the template message,
 586          * it just sets the argument to the prepare-commit-msg hook.
 587          */
 588         else if (in_merge)
 589                 hook_arg1 = "merge";
 590
 591         fp = fopen(git_path(commit_editmsg), "w");
 592         if (fp == NULL)
 593                 die_errno("could not open '%s'", git_path(commit_editmsg));
 594
 595         if (cleanup_mode != CLEANUP_NONE)
 596                 stripspace(&sb, 0);
 597
 598         if (signoff) {
 599                 struct strbuf sob = STRBUF_INIT;
 600                 int i;
 601
 602                 strbuf_addstr(&sob, sign_off_header);
 603                 strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
 604                                              getenv("GIT_COMMITTER_EMAIL")));
 605                 strbuf_addch(&sob, '\n');
 606                 for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
 607                         ; /* do nothing */
 608                 if (prefixcmp(sb.buf + i, sob.buf)) {
 609                         if (!i || !ends_rfc2822_footer(&sb))
 610                                 strbuf_addch(&sb, '\n');
 611                         strbuf_addbuf(&sb, &sob);
 612                 }
 613                 strbuf_release(&sob);
 614         }
 615
 616         if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
 617                 die_errno("could not write commit template");
 618
 619         strbuf_release(&sb);
 620
 621         determine_author_info();
 622
 623         /* This checks if committer ident is explicitly given */
 624         git_committer_info(0);
 625         if (use_editor && include_status) {
 626                 char *author_ident;
 627                 const char *committer_ident;
 628
 629                 if (in_merge)
 630                         fprintf(fp,
 631                                 "#\n"
 632                                 "# It looks like you may be committing a MERGE.\n"
 633                                 "# If this is not correct, please remove the file\n"
 634                                 "#      %s\n"
 635                                 "# and try again.\n"
 636                                 "#\n",
 637                                 git_path("MERGE_HEAD"));
 638
 639                 fprintf(fp,
 640                         "\n"
 641                         "# Please enter the commit message for your changes.");
 642                 if (cleanup_mode == CLEANUP_ALL)
 643                         fprintf(fp,
 644                                 " Lines starting\n"
 645                                 "# with '#' will be ignored, and an empty"
 646                                 " message aborts the commit.\n");
 647                 else /* CLEANUP_SPACE, that is. */
 648                         fprintf(fp,
 649                                 " Lines starting\n"
 650                                 "# with '#' will be kept; you may remove them"
 651                                 " yourself if you want to.\n"
 652                                 "# An empty message aborts the commit.\n");
 653                 if (only_include_assumed)
 654                         fprintf(fp, "# %s\n", only_include_assumed);
 655
 656                 author_ident = xstrdup(fmt_name(author_name, author_email));
 657                 committer_ident = fmt_name(getenv("GIT_COMMITTER_NAME"),
 658                                            getenv("GIT_COMMITTER_EMAIL"));
 659                 if (strcmp(author_ident, committer_ident))
 660                         fprintf(fp,
 661                                 "%s"
 662                                 "# Author:    %s\n",
 663                                 ident_shown++ ? "" : "#\n",
 664                                 author_ident);
 665                 free(author_ident);
 666
 667                 if (!user_ident_sufficiently_given())
 668                         fprintf(fp,
 669                                 "%s"
 670                                 "# Committer: %s\n",
 671                                 ident_shown++ ? "" : "#\n",
 672                                 committer_ident);
 673
 674                 if (ident_shown)
 675                         fprintf(fp, "#\n");
 676
 677                 saved_color_setting = s->use_color;
 678                 s->use_color = 0;
 679                 commitable = run_status(fp, index_file, prefix, 1, s);
 680                 s->use_color = saved_color_setting;
 681         } else {
 682                 unsigned char sha1[20];
 683                 const char *parent = "HEAD";
 684
 685                 if (!active_nr && read_cache() < 0)
 686                         die("Cannot read index");
 687
 688                 if (amend)
 689                         parent = "HEAD^1";
 690
 691                 if (get_sha1(parent, sha1))
 692                         commitable = !!active_nr;
 693                 else
 694                         commitable = index_differs_from(parent, 0);
 695         }
 696
 697         fclose(fp);
 698
 699         if (!commitable && !in_merge && !allow_empty &&
 700             !(amend && is_a_merge(head_sha1))) {
 701                 run_status(stdout, index_file, prefix, 0, s);
 702                 return 0;
 703         }
 704
 705         /*
 706          * Re-read the index as pre-commit hook could have updated it,
 707          * and write it out as a tree.  We must do this before we invoke
 708          * the editor and after we invoke run_status above.
 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                 error("Error building trees");
 717                 return 0;
 718         }
 719
 720         if (run_hook(index_file, "prepare-commit-msg",
 721                      git_path(commit_editmsg), hook_arg1, hook_arg2, NULL))
 722                 return 0;
 723
 724         if (use_editor) {
 725                 char index[PATH_MAX];
 726                 const char *env[2] = { index, NULL };
 727                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 728                 if (launch_editor(git_path(commit_editmsg), NULL, env)) {
 729                         fprintf(stderr,
 730                         "Please supply the message using either -m or -F option.\n");
 731                         exit(1);
 732                 }
 733         }
 734
 735         if (!no_verify &&
 736             run_hook(index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
 737                 return 0;
 738         }
 739
 740         return 1;
 741 }
 742
 743 /*
 744  * Find out if the message in the strbuf contains only whitespace and
 745  * Signed-off-by lines.
 746  */
 747 static int message_is_empty(struct strbuf *sb)
 748 {
 749         struct strbuf tmpl = STRBUF_INIT;
 750         const char *nl;
 751         int eol, i, start = 0;
 752
 753         if (cleanup_mode == CLEANUP_NONE && sb->len)
 754                 return 0;
 755
 756         /* See if the template is just a prefix of the message. */
 757         if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
 758                 stripspace(&tmpl, cleanup_mode == CLEANUP_ALL);
 759                 if (start + tmpl.len <= sb->len &&
 760                     memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
 761                         start += tmpl.len;
 762         }
 763         strbuf_release(&tmpl);
 764
 765         /* Check if the rest is just whitespace and Signed-of-by's. */
 766         for (i = start; i < sb->len; i++) {
 767                 nl = memchr(sb->buf + i, '\n', sb->len - i);
 768                 if (nl)
 769                         eol = nl - sb->buf;
 770                 else
 771                         eol = sb->len;
 772
 773                 if (strlen(sign_off_header) <= eol - i &&
 774                     !prefixcmp(sb->buf + i, sign_off_header)) {
 775                         i = eol;
 776                         continue;
 777                 }
 778                 while (i < eol)
 779                         if (!isspace(sb->buf[i++]))
 780                                 return 0;
 781         }
 782
 783         return 1;
 784 }
 785
 786 static const char *find_author_by_nickname(const char *name)
 787 {
 788         struct rev_info revs;
 789         struct commit *commit;
 790         struct strbuf buf = STRBUF_INIT;
 791         const char *av[20];
 792         int ac = 0;
 793
 794         init_revisions(&revs, NULL);
 795         strbuf_addf(&buf, "--author=%s", name);
 796         av[++ac] = "--all";
 797         av[++ac] = "-i";
 798         av[++ac] = buf.buf;
 799         av[++ac] = NULL;
 800         setup_revisions(ac, av, &revs, NULL);
 801         prepare_revision_walk(&revs);
 802         commit = get_revision(&revs);
 803         if (commit) {
 804                 struct pretty_print_context ctx = {0};
 805                 ctx.date_mode = DATE_NORMAL;
 806                 strbuf_release(&buf);
 807                 format_commit_message(commit, "%an <%ae>", &buf, &ctx);
 808                 return strbuf_detach(&buf, NULL);
 809         }
 810         die("No existing author found with '%s'", name);
 811 }
 812
 813
 814 static void handle_untracked_files_arg(struct wt_status *s)
 815 {
 816         if (!untracked_files_arg)
 817                 ; /* default already initialized */
 818         else if (!strcmp(untracked_files_arg, "no"))
 819                 s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
 820         else if (!strcmp(untracked_files_arg, "normal"))
 821                 s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
 822         else if (!strcmp(untracked_files_arg, "all"))
 823                 s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
 824         else
 825                 die("Invalid untracked files mode '%s'", untracked_files_arg);
 826 }
 827
 828 static int parse_and_validate_options(int argc, const char *argv[],
 829                                       const char * const usage[],
 830                                       const char *prefix,
 831                                       struct wt_status *s)
 832 {
 833         int f = 0;
 834
 835         argc = parse_options(argc, argv, prefix, builtin_commit_options, usage,
 836                              0);
 837
 838         if (force_author && !strchr(force_author, '>'))
 839                 force_author = find_author_by_nickname(force_author);
 840
 841         if (force_author && renew_authorship)
 842                 die("Using both --reset-author and --author does not make sense");
 843
 844         if (logfile || message.len || use_message)
 845                 use_editor = 0;
 846         if (edit_flag)
 847                 use_editor = 1;
 848         if (!use_editor)
 849                 setenv("GIT_EDITOR", ":", 1);
 850
 851         if (get_sha1("HEAD", head_sha1))
 852                 initial_commit = 1;
 853
 854         /* Sanity check options */
 855         if (amend && initial_commit)
 856                 die("You have nothing to amend.");
 857         if (amend && in_merge)
 858                 die("You are in the middle of a merge -- cannot amend.");
 859
 860         if (use_message)
 861                 f++;
 862         if (edit_message)
 863                 f++;
 864         if (logfile)
 865                 f++;
 866         if (f > 1)
 867                 die("Only one of -c/-C/-F can be used.");
 868         if (message.len && f > 0)
 869                 die("Option -m cannot be combined with -c/-C/-F.");
 870         if (edit_message)
 871                 use_message = edit_message;
 872         if (amend && !use_message)
 873                 use_message = "HEAD";
 874         if (!use_message && renew_authorship)
 875                 die("--reset-author can be used only with -C, -c or --amend.");
 876         if (use_message) {
 877                 unsigned char sha1[20];
 878                 static char utf8[] = "UTF-8";
 879                 const char *out_enc;
 880                 char *enc, *end;
 881                 struct commit *commit;
 882
 883                 if (get_sha1(use_message, sha1))
 884                         die("could not lookup commit %s", use_message);
 885                 commit = lookup_commit_reference(sha1);
 886                 if (!commit || parse_commit(commit))
 887                         die("could not parse commit %s", use_message);
 888
 889                 enc = strstr(commit->buffer, "\nencoding");
 890                 if (enc) {
 891                         end = strchr(enc + 10, '\n');
 892                         enc = xstrndup(enc + 10, end - (enc + 10));
 893                 } else {
 894                         enc = utf8;
 895                 }
 896                 out_enc = git_commit_encoding ? git_commit_encoding : utf8;
 897
 898                 if (strcmp(out_enc, enc))
 899                         use_message_buffer =
 900                                 reencode_string(commit->buffer, out_enc, enc);
 901
 902                 /*
 903                  * If we failed to reencode the buffer, just copy it
 904                  * byte for byte so the user can try to fix it up.
 905                  * This also handles the case where input and output
 906                  * encodings are identical.
 907                  */
 908                 if (use_message_buffer == NULL)
 909                         use_message_buffer = xstrdup(commit->buffer);
 910                 if (enc != utf8)
 911                         free(enc);
 912         }
 913
 914         if (!!also + !!only + !!all + !!interactive > 1)
 915                 die("Only one of --include/--only/--all/--interactive can be used.");
 916         if (argc == 0 && (also || (only && !amend)))
 917                 die("No paths with --include/--only does not make sense.");
 918         if (argc == 0 && only && amend)
 919                 only_include_assumed = "Clever... amending the last one with dirty index.";
 920         if (argc > 0 && !also && !only)
 921                 only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
 922         if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
 923                 cleanup_mode = use_editor ? CLEANUP_ALL : CLEANUP_SPACE;
 924         else if (!strcmp(cleanup_arg, "verbatim"))
 925                 cleanup_mode = CLEANUP_NONE;
 926         else if (!strcmp(cleanup_arg, "whitespace"))
 927                 cleanup_mode = CLEANUP_SPACE;
 928         else if (!strcmp(cleanup_arg, "strip"))
 929                 cleanup_mode = CLEANUP_ALL;
 930         else
 931                 die("Invalid cleanup mode %s", cleanup_arg);
 932
 933         handle_untracked_files_arg(s);
 934
 935         if (all && argc > 0)
 936                 die("Paths with -a does not make sense.");
 937         else if (interactive && argc > 0)
 938                 die("Paths with --interactive does not make sense.");
 939
 940         if (null_termination && status_format == STATUS_FORMAT_LONG)
 941                 status_format = STATUS_FORMAT_PORCELAIN;
 942         if (status_format != STATUS_FORMAT_LONG)
 943                 dry_run = 1;
 944
 945         return argc;
 946 }
 947
 948 static int dry_run_commit(int argc, const char **argv, const char *prefix,
 949                           struct wt_status *s)
 950 {
 951         int commitable;
 952         const char *index_file;
 953
 954         index_file = prepare_index(argc, argv, prefix, 1);
 955         commitable = run_status(stdout, index_file, prefix, 0, s);
 956         rollback_index_files();
 957
 958         return commitable ? 0 : 1;
 959 }
 960
 961 static int parse_status_slot(const char *var, int offset)
 962 {
 963         if (!strcasecmp(var+offset, "header"))
 964                 return WT_STATUS_HEADER;
 965         if (!strcasecmp(var+offset, "updated")
 966                 || !strcasecmp(var+offset, "added"))
 967                 return WT_STATUS_UPDATED;
 968         if (!strcasecmp(var+offset, "changed"))
 969                 return WT_STATUS_CHANGED;
 970         if (!strcasecmp(var+offset, "untracked"))
 971                 return WT_STATUS_UNTRACKED;
 972         if (!strcasecmp(var+offset, "nobranch"))
 973                 return WT_STATUS_NOBRANCH;
 974         if (!strcasecmp(var+offset, "unmerged"))
 975                 return WT_STATUS_UNMERGED;
 976         return -1;
 977 }
 978
 979 static int git_status_config(const char *k, const char *v, void *cb)
 980 {
 981         struct wt_status *s = cb;
 982
 983         if (!strcmp(k, "status.submodulesummary")) {
 984                 int is_bool;
 985                 s->submodule_summary = git_config_bool_or_int(k, v, &is_bool);
 986                 if (is_bool && s->submodule_summary)
 987                         s->submodule_summary = -1;
 988                 return 0;
 989         }
 990         if (!strcmp(k, "status.color") || !strcmp(k, "color.status")) {
 991                 s->use_color = git_config_colorbool(k, v, -1);
 992                 return 0;
 993         }
 994         if (!prefixcmp(k, "status.color.") || !prefixcmp(k, "color.status.")) {
 995                 int slot = parse_status_slot(k, 13);
 996                 if (slot < 0)
 997                         return 0;
 998                 if (!v)
 999                         return config_error_nonbool(k);
1000                 color_parse(v, k, s->color_palette[slot]);
1001                 return 0;
1002         }
1003         if (!strcmp(k, "status.relativepaths")) {
1004                 s->relative_paths = git_config_bool(k, v);
1005                 return 0;
1006         }
1007         if (!strcmp(k, "status.showuntrackedfiles")) {
1008                 if (!v)
1009                         return config_error_nonbool(k);
1010                 else if (!strcmp(v, "no"))
1011                         s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
1012                 else if (!strcmp(v, "normal"))
1013                         s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
1014                 else if (!strcmp(v, "all"))
1015                         s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
1016                 else
1017                         return error("Invalid untracked files mode '%s'", v);
1018                 return 0;
1019         }
1020         return git_diff_ui_config(k, v, NULL);
1021 }
1022
1023 int cmd_status(int argc, const char **argv, const char *prefix)
1024 {
1025         struct wt_status s;
1026         int fd;
1027         unsigned char sha1[20];
1028         static struct option builtin_status_options[] = {
1029                 OPT__VERBOSE(&verbose),
1030                 OPT_SET_INT('s', "short", &status_format,
1031                             "show status concisely", STATUS_FORMAT_SHORT),
1032                 OPT_SET_INT(0, "porcelain", &status_format,
1033                             "show porcelain output format",
1034                             STATUS_FORMAT_PORCELAIN),
1035                 OPT_BOOLEAN('z', "null", &null_termination,
1036                             "terminate entries with NUL"),
1037                 { OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
1038                   "mode",
1039                   "show untracked files, optional modes: all, normal, no. (Default: all)",
1040                   PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
1041                 OPT_END(),
1042         };
1043
1044         if (null_termination && status_format == STATUS_FORMAT_LONG)
1045                 status_format = STATUS_FORMAT_PORCELAIN;
1046
1047         wt_status_prepare(&s);
1048         git_config(git_status_config, &s);
1049         in_merge = file_exists(git_path("MERGE_HEAD"));
1050         argc = parse_options(argc, argv, prefix,
1051                              builtin_status_options,
1052                              builtin_status_usage, 0);
1053         handle_untracked_files_arg(&s);
1054
1055         if (*argv)
1056                 s.pathspec = get_pathspec(prefix, argv);
1057
1058         read_cache_preload(s.pathspec);
1059         refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, s.pathspec, NULL, NULL);
1060
1061         fd = hold_locked_index(&index_lock, 0);
1062         if (0 <= fd) {
1063                 if (!write_cache(fd, active_cache, active_nr))
1064                         commit_locked_index(&index_lock);
1065                 rollback_lock_file(&index_lock);
1066         }
1067
1068         s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
1069         s.in_merge = in_merge;
1070         wt_status_collect(&s);
1071
1072         if (s.relative_paths)
1073                 s.prefix = prefix;
1074         if (s.use_color == -1)
1075                 s.use_color = git_use_color_default;
1076         if (diff_use_color_default == -1)
1077                 diff_use_color_default = git_use_color_default;
1078
1079         switch (status_format) {
1080         case STATUS_FORMAT_SHORT:
1081                 wt_shortstatus_print(&s, null_termination);
1082                 break;
1083         case STATUS_FORMAT_PORCELAIN:
1084                 wt_porcelain_print(&s, null_termination);
1085                 break;
1086         case STATUS_FORMAT_LONG:
1087                 s.verbose = verbose;
1088                 wt_status_print(&s);
1089                 break;
1090         }
1091         return 0;
1092 }
1093
1094 static void print_summary(const char *prefix, const unsigned char *sha1)
1095 {
1096         struct rev_info rev;
1097         struct commit *commit;
1098         struct strbuf format = STRBUF_INIT;
1099         unsigned char junk_sha1[20];
1100         const char *head = resolve_ref("HEAD", junk_sha1, 0, NULL);
1101         struct pretty_print_context pctx = {0};
1102         struct strbuf author_ident = STRBUF_INIT;
1103         struct strbuf committer_ident = STRBUF_INIT;
1104
1105         commit = lookup_commit(sha1);
1106         if (!commit)
1107                 die("couldn't look up newly created commit");
1108         if (!commit || parse_commit(commit))
1109                 die("could not parse newly created commit");
1110
1111         strbuf_addstr(&format, "format:%h] %s");
1112
1113         format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
1114         format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
1115         if (strbuf_cmp(&author_ident, &committer_ident)) {
1116                 strbuf_addstr(&format, "\n Author: ");
1117                 strbuf_addbuf_percentquote(&format, &author_ident);
1118         }
1119         if (!user_ident_sufficiently_given()) {
1120                 strbuf_addstr(&format, "\n Committer: ");
1121                 strbuf_addbuf_percentquote(&format, &committer_ident);
1122                 if (advice_implicit_identity) {
1123                         strbuf_addch(&format, '\n');
1124                         strbuf_addstr(&format, implicit_ident_advice);
1125                 }
1126         }
1127         strbuf_release(&author_ident);
1128         strbuf_release(&committer_ident);
1129
1130         init_revisions(&rev, prefix);
1131         setup_revisions(0, NULL, &rev, NULL);
1132
1133         rev.abbrev = 0;
1134         rev.diff = 1;
1135         rev.diffopt.output_format =
1136                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
1137
1138         rev.verbose_header = 1;
1139         rev.show_root_diff = 1;
1140         get_commit_format(format.buf, &rev);
1141         rev.always_show_header = 0;
1142         rev.diffopt.detect_rename = 1;
1143         rev.diffopt.rename_limit = 100;
1144         rev.diffopt.break_opt = 0;
1145         diff_setup_done(&rev.diffopt);
1146
1147         printf("[%s%s ",
1148                 !prefixcmp(head, "refs/heads/") ?
1149                         head + 11 :
1150                         !strcmp(head, "HEAD") ?
1151                                 "detached HEAD" :
1152                                 head,
1153                 initial_commit ? " (root-commit)" : "");
1154
1155         if (!log_tree_commit(&rev, commit)) {
1156                 struct pretty_print_context ctx = {0};
1157                 struct strbuf buf = STRBUF_INIT;
1158                 ctx.date_mode = DATE_NORMAL;
1159                 format_commit_message(commit, format.buf + 7, &buf, &ctx);
1160                 printf("%s\n", buf.buf);
1161                 strbuf_release(&buf);
1162         }
1163         strbuf_release(&format);
1164 }
1165
1166 static int git_commit_config(const char *k, const char *v, void *cb)
1167 {
1168         struct wt_status *s = cb;
1169
1170         if (!strcmp(k, "commit.template"))
1171                 return git_config_pathname(&template_file, k, v);
1172         if (!strcmp(k, "commit.status")) {
1173                 include_status = git_config_bool(k, v);
1174                 return 0;
1175         }
1176
1177         return git_status_config(k, v, s);
1178 }
1179
1180 static const char post_rewrite_hook[] = "hooks/post-rewrite";
1181
1182 static int run_rewrite_hook(const unsigned char *oldsha1,
1183                             const unsigned char *newsha1)
1184 {
1185         /* oldsha1 SP newsha1 LF NUL */
1186         static char buf[2*40 + 3];
1187         struct child_process proc;
1188         const char *argv[3];
1189         int code;
1190         size_t n;
1191
1192         if (access(git_path(post_rewrite_hook), X_OK) < 0)
1193                 return 0;
1194
1195         argv[0] = git_path(post_rewrite_hook);
1196         argv[1] = "amend";
1197         argv[2] = NULL;
1198
1199         memset(&proc, 0, sizeof(proc));
1200         proc.argv = argv;
1201         proc.in = -1;
1202         proc.stdout_to_stderr = 1;
1203
1204         code = start_command(&proc);
1205         if (code)
1206                 return code;
1207         n = snprintf(buf, sizeof(buf), "%s %s\n",
1208                      sha1_to_hex(oldsha1), sha1_to_hex(newsha1));
1209         write_in_full(proc.in, buf, n);
1210         close(proc.in);
1211         return finish_command(&proc);
1212 }
1213
1214 int cmd_commit(int argc, const char **argv, const char *prefix)
1215 {
1216         struct strbuf sb = STRBUF_INIT;
1217         const char *index_file, *reflog_msg;
1218         char *nl, *p;
1219         unsigned char commit_sha1[20];
1220         struct ref_lock *ref_lock;
1221         struct commit_list *parents = NULL, **pptr = &parents;
1222         struct stat statbuf;
1223         int allow_fast_forward = 1;
1224         struct wt_status s;
1225
1226         wt_status_prepare(&s);
1227         git_config(git_commit_config, &s);
1228         in_merge = file_exists(git_path("MERGE_HEAD"));
1229         s.in_merge = in_merge;
1230
1231         if (s.use_color == -1)
1232                 s.use_color = git_use_color_default;
1233         argc = parse_and_validate_options(argc, argv, builtin_commit_usage,
1234                                           prefix, &s);
1235         if (dry_run) {
1236                 if (diff_use_color_default == -1)
1237                         diff_use_color_default = git_use_color_default;
1238                 return dry_run_commit(argc, argv, prefix, &s);
1239         }
1240         index_file = prepare_index(argc, argv, prefix, 0);
1241
1242         /* Set up everything for writing the commit object.  This includes
1243            running hooks, writing the trees, and interacting with the user.  */
1244         if (!prepare_to_commit(index_file, prefix, &s)) {
1245                 rollback_index_files();
1246                 return 1;
1247         }
1248
1249         /* Determine parents */
1250         if (initial_commit) {
1251                 reflog_msg = "commit (initial)";
1252         } else if (amend) {
1253                 struct commit_list *c;
1254                 struct commit *commit;
1255
1256                 reflog_msg = "commit (amend)";
1257                 commit = lookup_commit(head_sha1);
1258                 if (!commit || parse_commit(commit))
1259                         die("could not parse HEAD commit");
1260
1261                 for (c = commit->parents; c; c = c->next)
1262                         pptr = &commit_list_insert(c->item, pptr)->next;
1263         } else if (in_merge) {
1264                 struct strbuf m = STRBUF_INIT;
1265                 FILE *fp;
1266
1267                 reflog_msg = "commit (merge)";
1268                 pptr = &commit_list_insert(lookup_commit(head_sha1), pptr)->next;
1269                 fp = fopen(git_path("MERGE_HEAD"), "r");
1270                 if (fp == NULL)
1271                         die_errno("could not open '%s' for reading",
1272                                   git_path("MERGE_HEAD"));
1273                 while (strbuf_getline(&m, fp, '\n') != EOF) {
1274                         unsigned char sha1[20];
1275                         if (get_sha1_hex(m.buf, sha1) < 0)
1276                                 die("Corrupt MERGE_HEAD file (%s)", m.buf);
1277                         pptr = &commit_list_insert(lookup_commit(sha1), pptr)->next;
1278                 }
1279                 fclose(fp);
1280                 strbuf_release(&m);
1281                 if (!stat(git_path("MERGE_MODE"), &statbuf)) {
1282                         if (strbuf_read_file(&sb, git_path("MERGE_MODE"), 0) < 0)
1283                                 die_errno("could not read MERGE_MODE");
1284                         if (!strcmp(sb.buf, "no-ff"))
1285                                 allow_fast_forward = 0;
1286                 }
1287                 if (allow_fast_forward)
1288                         parents = reduce_heads(parents);
1289         } else {
1290                 reflog_msg = "commit";
1291                 pptr = &commit_list_insert(lookup_commit(head_sha1), pptr)->next;
1292         }
1293
1294         /* Finally, get the commit message */
1295         strbuf_reset(&sb);
1296         if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
1297                 int saved_errno = errno;
1298                 rollback_index_files();
1299                 die("could not read commit message: %s", strerror(saved_errno));
1300         }
1301
1302         /* Truncate the message just before the diff, if any. */
1303         if (verbose) {
1304                 p = strstr(sb.buf, "\ndiff --git ");
1305                 if (p != NULL)
1306                         strbuf_setlen(&sb, p - sb.buf + 1);
1307         }
1308
1309         if (cleanup_mode != CLEANUP_NONE)
1310                 stripspace(&sb, cleanup_mode == CLEANUP_ALL);
1311         if (message_is_empty(&sb) && !allow_empty_message) {
1312                 rollback_index_files();
1313                 fprintf(stderr, "Aborting commit due to empty commit message.\n");
1314                 exit(1);
1315         }
1316
1317         if (commit_tree(sb.buf, active_cache_tree->sha1, parents, commit_sha1,
1318                         fmt_ident(author_name, author_email, author_date,
1319                                 IDENT_ERROR_ON_NO_NAME))) {
1320                 rollback_index_files();
1321                 die("failed to write commit object");
1322         }
1323
1324         ref_lock = lock_any_ref_for_update("HEAD",
1325                                            initial_commit ? NULL : head_sha1,
1326                                            0);
1327
1328         nl = strchr(sb.buf, '\n');
1329         if (nl)
1330                 strbuf_setlen(&sb, nl + 1 - sb.buf);
1331         else
1332                 strbuf_addch(&sb, '\n');
1333         strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
1334         strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
1335
1336         if (!ref_lock) {
1337                 rollback_index_files();
1338                 die("cannot lock HEAD ref");
1339         }
1340         if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
1341                 rollback_index_files();
1342                 die("cannot update HEAD ref");
1343         }
1344
1345         unlink(git_path("MERGE_HEAD"));
1346         unlink(git_path("MERGE_MSG"));
1347         unlink(git_path("MERGE_MODE"));
1348         unlink(git_path("SQUASH_MSG"));
1349
1350         if (commit_index_files())
1351                 die ("Repository has been updated, but unable to write\n"
1352                      "new_index file. Check that disk is not full or quota is\n"
1353                      "not exceeded, and then \"git reset HEAD\" to recover.");
1354
1355         rerere(0);
1356         run_hook(get_index_file(), "post-commit", NULL);
1357         if (amend && !no_post_rewrite) {
1358                 struct notes_rewrite_cfg *cfg;
1359                 cfg = init_copy_notes_for_rewrite("amend");
1360                 if (cfg) {
1361                         copy_note_for_rewrite(cfg, head_sha1, commit_sha1);
1362                         finish_copy_notes_for_rewrite(cfg);
1363                 }
1364                 run_rewrite_hook(head_sha1, commit_sha1);
1365         }
1366         if (!quiet)
1367                 print_summary(prefix, commit_sha1);
1368
1369         return 0;
1370 }