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)
 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
 300         wt_status_print(&s);
 301
 302         return s.commitable;
 303 }
 304
 305 static const char sign_off_header[] = "Signed-off-by: ";
 306
 307 static int prepare_log_message(const char *index_file, const char *prefix)
 308 {
 309         struct stat statbuf;
 310         int commitable, saved_color_setting;
 311         struct strbuf sb;
 312         char *buffer;
 313         FILE *fp;
 314
 315         strbuf_init(&sb, 0);
 316         if (message.len) {
 317                 strbuf_addbuf(&sb, &message);
 318         } else if (logfile && !strcmp(logfile, "-")) {
 319                 if (isatty(0))
 320                         fprintf(stderr, "(reading log message from standard input)\n");
 321                 if (strbuf_read(&sb, 0, 0) < 0)
 322                         die("could not read log from standard input");
 323         } else if (logfile) {
 324                 if (strbuf_read_file(&sb, logfile, 0) < 0)
 325                         die("could not read log file '%s': %s",
 326                             logfile, strerror(errno));
 327         } else if (use_message) {
 328                 buffer = strstr(use_message_buffer, "\n\n");
 329                 if (!buffer || buffer[2] == '\0')
 330                         die("commit has empty message");
 331                 strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
 332         } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
 333                 if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
 334                         die("could not read MERGE_MSG: %s", strerror(errno));
 335         } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
 336                 if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
 337                         die("could not read SQUASH_MSG: %s", strerror(errno));
 338         } else if (template_file && !stat(template_file, &statbuf)) {
 339                 if (strbuf_read_file(&sb, template_file, 0) < 0)
 340                         die("could not read %s: %s",
 341                             template_file, strerror(errno));
 342         }
 343
 344         fp = fopen(git_path(commit_editmsg), "w");
 345         if (fp == NULL)
 346                 die("could not open %s", git_path(commit_editmsg));
 347
 348         stripspace(&sb, 0);
 349
 350         if (signoff) {
 351                 struct strbuf sob;
 352                 int i;
 353
 354                 strbuf_init(&sob, 0);
 355                 strbuf_addstr(&sob, sign_off_header);
 356                 strbuf_addstr(&sob, fmt_name(getenv("GIT_COMMITTER_NAME"),
 357                                              getenv("GIT_COMMITTER_EMAIL")));
 358                 strbuf_addch(&sob, '\n');
 359                 for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
 360                         ; /* do nothing */
 361                 if (prefixcmp(sb.buf + i, sob.buf)) {
 362                         if (prefixcmp(sb.buf + i, sign_off_header))
 363                                 strbuf_addch(&sb, '\n');
 364                         strbuf_addbuf(&sb, &sob);
 365                 }
 366                 strbuf_release(&sob);
 367         }
 368
 369         if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
 370                 die("could not write commit template: %s", strerror(errno));
 371
 372         strbuf_release(&sb);
 373
 374         if (no_edit) {
 375                 struct rev_info rev;
 376                 unsigned char sha1[40];
 377
 378                 fclose(fp);
 379
 380                 if (!active_nr && read_cache() < 0)
 381                         die("Cannot read index");
 382
 383                 if (get_sha1("HEAD", sha1) != 0)
 384                         return !!active_nr;
 385
 386                 init_revisions(&rev, "");
 387                 rev.abbrev = 0;
 388                 setup_revisions(0, NULL, &rev, "HEAD");
 389                 DIFF_OPT_SET(&rev.diffopt, QUIET);
 390                 DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
 391                 run_diff_index(&rev, 1 /* cached */);
 392
 393                 return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
 394         }
 395
 396         if (in_merge && !no_edit)
 397                 fprintf(fp,
 398                         "#\n"
 399                         "# It looks like you may be committing a MERGE.\n"
 400                         "# If this is not correct, please remove the file\n"
 401                         "#      %s\n"
 402                         "# and try again.\n"
 403                         "#\n",
 404                         git_path("MERGE_HEAD"));
 405
 406         fprintf(fp,
 407                 "\n"
 408                 "# Please enter the commit message for your changes.\n"
 409                 "# (Comment lines starting with '#' will not be included)\n");
 410         if (only_include_assumed)
 411                 fprintf(fp, "# %s\n", only_include_assumed);
 412
 413         saved_color_setting = wt_status_use_color;
 414         wt_status_use_color = 0;
 415         commitable = run_status(fp, index_file, prefix);
 416         wt_status_use_color = saved_color_setting;
 417
 418         fclose(fp);
 419
 420         return commitable;
 421 }
 422
 423 /*
 424  * Find out if the message starting at position 'start' in the strbuf
 425  * contains only whitespace and Signed-off-by lines.
 426  */
 427 static int message_is_empty(struct strbuf *sb, int start)
 428 {
 429         struct strbuf tmpl;
 430         const char *nl;
 431         int eol, i;
 432
 433         /* See if the template is just a prefix of the message. */
 434         strbuf_init(&tmpl, 0);
 435         if (template_file && strbuf_read_file(&tmpl, template_file, 0) > 0) {
 436                 stripspace(&tmpl, 1);
 437                 if (start + tmpl.len <= sb->len &&
 438                     memcmp(tmpl.buf, sb->buf + start, tmpl.len) == 0)
 439                         start += tmpl.len;
 440         }
 441         strbuf_release(&tmpl);
 442
 443         /* Check if the rest is just whitespace and Signed-of-by's. */
 444         for (i = start; i < sb->len; i++) {
 445                 nl = memchr(sb->buf + i, '\n', sb->len - i);
 446                 if (nl)
 447                         eol = nl - sb->buf;
 448                 else
 449                         eol = sb->len;
 450
 451                 if (strlen(sign_off_header) <= eol - i &&
 452                     !prefixcmp(sb->buf + i, sign_off_header)) {
 453                         i = eol;
 454                         continue;
 455                 }
 456                 while (i < eol)
 457                         if (!isspace(sb->buf[i++]))
 458                                 return 0;
 459         }
 460
 461         return 1;
 462 }
 463
 464 static void determine_author_info(struct strbuf *sb)
 465 {
 466         char *name, *email, *date;
 467
 468         name = getenv("GIT_AUTHOR_NAME");
 469         email = getenv("GIT_AUTHOR_EMAIL");
 470         date = getenv("GIT_AUTHOR_DATE");
 471
 472         if (use_message) {
 473                 const char *a, *lb, *rb, *eol;
 474
 475                 a = strstr(use_message_buffer, "\nauthor ");
 476                 if (!a)
 477                         die("invalid commit: %s", use_message);
 478
 479                 lb = strstr(a + 8, " <");
 480                 rb = strstr(a + 8, "> ");
 481                 eol = strchr(a + 8, '\n');
 482                 if (!lb || !rb || !eol)
 483                         die("invalid commit: %s", use_message);
 484
 485                 name = xstrndup(a + 8, lb - (a + 8));
 486                 email = xstrndup(lb + 2, rb - (lb + 2));
 487                 date = xstrndup(rb + 2, eol - (rb + 2));
 488         }
 489
 490         if (force_author) {
 491                 const char *lb = strstr(force_author, " <");
 492                 const char *rb = strchr(force_author, '>');
 493
 494                 if (!lb || !rb)
 495                         die("malformed --author parameter");
 496                 name = xstrndup(force_author, lb - force_author);
 497                 email = xstrndup(lb + 2, rb - (lb + 2));
 498         }
 499
 500         strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, 1));
 501 }
 502
 503 static int parse_and_validate_options(int argc, const char *argv[],
 504                                       const char * const usage[])
 505 {
 506         int f = 0;
 507
 508         argc = parse_options(argc, argv, builtin_commit_options, usage, 0);
 509
 510         if (logfile || message.len || use_message)
 511                 no_edit = 1;
 512         if (edit_flag)
 513                 no_edit = 0;
 514
 515         if (get_sha1("HEAD", head_sha1))
 516                 initial_commit = 1;
 517
 518         if (!get_sha1("MERGE_HEAD", merge_head_sha1))
 519                 in_merge = 1;
 520
 521         /* Sanity check options */
 522         if (amend && initial_commit)
 523                 die("You have nothing to amend.");
 524         if (amend && in_merge)
 525                 die("You are in the middle of a merge -- cannot amend.");
 526
 527         if (use_message)
 528                 f++;
 529         if (edit_message)
 530                 f++;
 531         if (logfile)
 532                 f++;
 533         if (f > 1)
 534                 die("Only one of -c/-C/-F can be used.");
 535         if (message.len && f > 0)
 536                 die("Option -m cannot be combined with -c/-C/-F.");
 537         if (edit_message)
 538                 use_message = edit_message;
 539         if (amend)
 540                 use_message = "HEAD";
 541         if (use_message) {
 542                 unsigned char sha1[20];
 543                 static char utf8[] = "UTF-8";
 544                 const char *out_enc;
 545                 char *enc, *end;
 546                 struct commit *commit;
 547
 548                 if (get_sha1(use_message, sha1))
 549                         die("could not lookup commit %s", use_message);
 550                 commit = lookup_commit(sha1);
 551                 if (!commit || parse_commit(commit))
 552                         die("could not parse commit %s", use_message);
 553
 554                 enc = strstr(commit->buffer, "\nencoding");
 555                 if (enc) {
 556                         end = strchr(enc + 10, '\n');
 557                         enc = xstrndup(enc + 10, end - (enc + 10));
 558                 } else {
 559                         enc = utf8;
 560                 }
 561                 out_enc = git_commit_encoding ? git_commit_encoding : utf8;
 562
 563                 if (strcmp(out_enc, enc))
 564                         use_message_buffer =
 565                                 reencode_string(commit->buffer, out_enc, enc);
 566
 567                 /*
 568                  * If we failed to reencode the buffer, just copy it
 569                  * byte for byte so the user can try to fix it up.
 570                  * This also handles the case where input and output
 571                  * encodings are identical.
 572                  */
 573                 if (use_message_buffer == NULL)
 574                         use_message_buffer = xstrdup(commit->buffer);
 575                 if (enc != utf8)
 576                         free(enc);
 577         }
 578
 579         if (!!also + !!only + !!all + !!interactive > 1)
 580                 die("Only one of --include/--only/--all/--interactive can be used.");
 581         if (argc == 0 && (also || (only && !amend)))
 582                 die("No paths with --include/--only does not make sense.");
 583         if (argc == 0 && only && amend)
 584                 only_include_assumed = "Clever... amending the last one with dirty index.";
 585         if (argc > 0 && !also && !only) {
 586                 only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
 587                 also = 0;
 588         }
 589
 590         if (all && argc > 0)
 591                 die("Paths with -a does not make sense.");
 592         else if (interactive && argc > 0)
 593                 die("Paths with --interactive does not make sense.");
 594
 595         return argc;
 596 }
 597
 598 int cmd_status(int argc, const char **argv, const char *prefix)
 599 {
 600         const char *index_file;
 601         int commitable;
 602
 603         git_config(git_status_config);
 604
 605         argc = parse_and_validate_options(argc, argv, builtin_status_usage);
 606
 607         index_file = prepare_index(argc, argv, prefix);
 608
 609         commitable = run_status(stdout, index_file, prefix);
 610
 611         rollback_index_files();
 612
 613         return commitable ? 0 : 1;
 614 }
 615
 616 static int run_hook(const char *index_file, const char *name, const char *arg)
 617 {
 618         struct child_process hook;
 619         const char *argv[3], *env[2];
 620         char index[PATH_MAX];
 621
 622         argv[0] = git_path("hooks/%s", name);
 623         argv[1] = arg;
 624         argv[2] = NULL;
 625         snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 626         env[0] = index;
 627         env[1] = NULL;
 628
 629         if (access(argv[0], X_OK) < 0)
 630                 return 0;
 631
 632         memset(&hook, 0, sizeof(hook));
 633         hook.argv = argv;
 634         hook.no_stdin = 1;
 635         hook.stdout_to_stderr = 1;
 636         hook.env = env;
 637
 638         return run_command(&hook);
 639 }
 640
 641 static void print_summary(const char *prefix, const unsigned char *sha1)
 642 {
 643         struct rev_info rev;
 644         struct commit *commit;
 645
 646         commit = lookup_commit(sha1);
 647         if (!commit)
 648                 die("couldn't look up newly created commit");
 649         if (!commit || parse_commit(commit))
 650                 die("could not parse newly created commit");
 651
 652         init_revisions(&rev, prefix);
 653         setup_revisions(0, NULL, &rev, NULL);
 654
 655         rev.abbrev = 0;
 656         rev.diff = 1;
 657         rev.diffopt.output_format =
 658                 DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
 659
 660         rev.verbose_header = 1;
 661         rev.show_root_diff = 1;
 662         rev.commit_format = get_commit_format("format:%h: %s");
 663         rev.always_show_header = 1;
 664
 665         printf("Created %scommit ", initial_commit ? "initial " : "");
 666
 667         log_tree_commit(&rev, commit);
 668         printf("\n");
 669 }
 670
 671 int git_commit_config(const char *k, const char *v)
 672 {
 673         if (!strcmp(k, "commit.template")) {
 674                 template_file = xstrdup(v);
 675                 return 0;
 676         }
 677
 678         return git_status_config(k, v);
 679 }
 680
 681 static int is_a_merge(const unsigned char *sha1)
 682 {
 683         struct commit *commit = lookup_commit(sha1);
 684         if (!commit || parse_commit(commit))
 685                 die("could not parse HEAD commit");
 686         return !!(commit->parents && commit->parents->next);
 687 }
 688
 689 static const char commit_utf8_warn[] =
 690 "Warning: commit message does not conform to UTF-8.\n"
 691 "You may want to amend it after fixing the message, or set the config\n"
 692 "variable i18n.commitencoding to the encoding your project uses.\n";
 693
 694 int cmd_commit(int argc, const char **argv, const char *prefix)
 695 {
 696         int header_len;
 697         struct strbuf sb;
 698         const char *index_file, *reflog_msg;
 699         char *nl, *p;
 700         unsigned char commit_sha1[20];
 701         struct ref_lock *ref_lock;
 702
 703         git_config(git_commit_config);
 704
 705         argc = parse_and_validate_options(argc, argv, builtin_commit_usage);
 706
 707         index_file = prepare_index(argc, argv, prefix);
 708
 709         if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
 710                 rollback_index_files();
 711                 return 1;
 712         }
 713
 714         if (!prepare_log_message(index_file, prefix) && !in_merge &&
 715             !allow_empty && !(amend && is_a_merge(head_sha1))) {
 716                 run_status(stdout, index_file, prefix);
 717                 rollback_index_files();
 718                 unlink(commit_editmsg);
 719                 return 1;
 720         }
 721
 722         /*
 723          * Re-read the index as pre-commit hook could have updated it,
 724          * and write it out as a tree.
 725          */
 726         discard_cache();
 727         read_cache_from(index_file);
 728         if (!active_cache_tree)
 729                 active_cache_tree = cache_tree();
 730         if (cache_tree_update(active_cache_tree,
 731                               active_cache, active_nr, 0, 0) < 0) {
 732                 rollback_index_files();
 733                 die("Error building trees");
 734         }
 735
 736         /*
 737          * The commit object
 738          */
 739         strbuf_init(&sb, 0);
 740         strbuf_addf(&sb, "tree %s\n",
 741                     sha1_to_hex(active_cache_tree->sha1));
 742
 743         /* Determine parents */
 744         if (initial_commit) {
 745                 reflog_msg = "commit (initial)";
 746         } else if (amend) {
 747                 struct commit_list *c;
 748                 struct commit *commit;
 749
 750                 reflog_msg = "commit (amend)";
 751                 commit = lookup_commit(head_sha1);
 752                 if (!commit || parse_commit(commit))
 753                         die("could not parse HEAD commit");
 754
 755                 for (c = commit->parents; c; c = c->next)
 756                         strbuf_addf(&sb, "parent %s\n",
 757                                       sha1_to_hex(c->item->object.sha1));
 758         } else if (in_merge) {
 759                 struct strbuf m;
 760                 FILE *fp;
 761
 762                 reflog_msg = "commit (merge)";
 763                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
 764                 strbuf_init(&m, 0);
 765                 fp = fopen(git_path("MERGE_HEAD"), "r");
 766                 if (fp == NULL)
 767                         die("could not open %s for reading: %s",
 768                             git_path("MERGE_HEAD"), strerror(errno));
 769                 while (strbuf_getline(&m, fp, '\n') != EOF)
 770                         strbuf_addf(&sb, "parent %s\n", m.buf);
 771                 fclose(fp);
 772                 strbuf_release(&m);
 773         } else {
 774                 reflog_msg = "commit";
 775                 strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
 776         }
 777
 778         determine_author_info(&sb);
 779         strbuf_addf(&sb, "committer %s\n", git_committer_info(1));
 780         if (!is_encoding_utf8(git_commit_encoding))
 781                 strbuf_addf(&sb, "encoding %s\n", git_commit_encoding);
 782         strbuf_addch(&sb, '\n');
 783
 784         /* Get the commit message and validate it */
 785         header_len = sb.len;
 786         if (!no_edit) {
 787                 char index[PATH_MAX];
 788                 const char *env[2] = { index, NULL };
 789                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 790                 launch_editor(git_path(commit_editmsg), &sb, env);
 791         } else if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
 792                 rollback_index_files();
 793                 die("could not read commit message");
 794         }
 795         if (!no_verify &&
 796             run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
 797                 rollback_index_files();
 798                 exit(1);
 799         }
 800
 801         /* Truncate the message just before the diff, if any. */
 802         p = strstr(sb.buf, "\ndiff --git a/");
 803         if (p != NULL)
 804                 strbuf_setlen(&sb, p - sb.buf + 1);
 805
 806         stripspace(&sb, 1);
 807         if (sb.len < header_len || message_is_empty(&sb, header_len)) {
 808                 rollback_index_files();
 809                 die("no commit message?  aborting commit.");
 810         }
 811         strbuf_addch(&sb, '\0');
 812         if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))
 813                 fprintf(stderr, commit_utf8_warn);
 814
 815         if (write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
 816                 rollback_index_files();
 817                 die("failed to write commit object");
 818         }
 819
 820         ref_lock = lock_any_ref_for_update("HEAD",
 821                                            initial_commit ? NULL : head_sha1,
 822                                            0);
 823
 824         nl = strchr(sb.buf + header_len, '\n');
 825         if (nl)
 826                 strbuf_setlen(&sb, nl + 1 - sb.buf);
 827         else
 828                 strbuf_addch(&sb, '\n');
 829         strbuf_remove(&sb, 0, header_len);
 830         strbuf_insert(&sb, 0, reflog_msg, strlen(reflog_msg));
 831         strbuf_insert(&sb, strlen(reflog_msg), ": ", 2);
 832
 833         if (!ref_lock) {
 834                 rollback_index_files();
 835                 die("cannot lock HEAD ref");
 836         }
 837         if (write_ref_sha1(ref_lock, commit_sha1, sb.buf) < 0) {
 838                 rollback_index_files();
 839                 die("cannot update HEAD ref");
 840         }
 841
 842         unlink(git_path("MERGE_HEAD"));
 843         unlink(git_path("MERGE_MSG"));
 844
 845         commit_index_files();
 846
 847         rerere();
 848         run_hook(get_index_file(), "post-commit", NULL);
 849         if (!quiet)
 850                 print_summary(prefix, commit_sha1);
 851
 852         return 0;
 853 }