builtin/log.c

   1 /*
   2  * Builtin "git log" and related commands (show, whatchanged)
   3  *
   4  * (C) Copyright 2006 Linus Torvalds
   5  *               2006 Junio Hamano
   6  */
   7 #include "cache.h"
   8 #include "color.h"
   9 #include "commit.h"
  10 #include "diff.h"
  11 #include "revision.h"
  12 #include "log-tree.h"
  13 #include "builtin.h"
  14 #include "tag.h"
  15 #include "reflog-walk.h"
  16 #include "patch-ids.h"
  17 #include "run-command.h"
  18 #include "shortlog.h"
  19 #include "remote.h"
  20 #include "string-list.h"
  21 #include "parse-options.h"
  22 #include "branch.h"
  23
  24 /* Set a default date-time format for git log ("log.date" config variable) */
  25 static const char *default_date_mode = NULL;
  26
  27 static int default_abbrev_commit;
  28 static int default_show_root = 1;
  29 static int decoration_style;
  30 static int decoration_given;
  31 static const char *fmt_patch_subject_prefix = "PATCH";
  32 static const char *fmt_pretty;
  33
  34 static const char * const builtin_log_usage[] = {
  35         "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
  36         "   or: git show [options] <object>...",
  37         NULL
  38 };
  39
  40 static int parse_decoration_style(const char *var, const char *value)
  41 {
  42         switch (git_config_maybe_bool(var, value)) {
  43         case 1:
  44                 return DECORATE_SHORT_REFS;
  45         case 0:
  46                 return 0;
  47         default:
  48                 break;
  49         }
  50         if (!strcmp(value, "full"))
  51                 return DECORATE_FULL_REFS;
  52         else if (!strcmp(value, "short"))
  53                 return DECORATE_SHORT_REFS;
  54         return -1;
  55 }
  56
  57 static int decorate_callback(const struct option *opt, const char *arg, int unset)
  58 {
  59         if (unset)
  60                 decoration_style = 0;
  61         else if (arg)
  62                 decoration_style = parse_decoration_style("command line", arg);
  63         else
  64                 decoration_style = DECORATE_SHORT_REFS;
  65
  66         if (decoration_style < 0)
  67                 die("invalid --decorate option: %s", arg);
  68
  69         decoration_given = 1;
  70
  71         return 0;
  72 }
  73
  74 static void cmd_log_init_defaults(struct rev_info *rev)
  75 {
  76         if (fmt_pretty)
  77                 get_commit_format(fmt_pretty, rev);
  78         rev->verbose_header = 1;
  79         DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
  80         rev->diffopt.stat_width = -1; /* use full terminal width */
  81         rev->diffopt.stat_graph_width = -1; /* respect statGraphWidth config */
  82         rev->abbrev_commit = default_abbrev_commit;
  83         rev->show_root_diff = default_show_root;
  84         rev->subject_prefix = fmt_patch_subject_prefix;
  85         DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
  86
  87         if (default_date_mode)
  88                 rev->date_mode = parse_date_format(default_date_mode);
  89 }
  90
  91 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
  92                          struct rev_info *rev, struct setup_revision_opt *opt)
  93 {
  94         struct userformat_want w;
  95         int quiet = 0, source = 0;
  96
  97         const struct option builtin_log_options[] = {
  98                 OPT_BOOLEAN(0, "quiet", &quiet, "suppress diff output"),
  99                 OPT_BOOLEAN(0, "source", &source, "show source"),
 100                 { OPTION_CALLBACK, 0, "decorate", NULL, NULL, "decorate options",
 101                   PARSE_OPT_OPTARG, decorate_callback},
 102                 OPT_END()
 103         };
 104
 105         argc = parse_options(argc, argv, prefix,
 106                              builtin_log_options, builtin_log_usage,
 107                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 108                              PARSE_OPT_KEEP_DASHDASH);
 109
 110         argc = setup_revisions(argc, argv, rev, opt);
 111         if (quiet)
 112                 rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
 113
 114         /* Any arguments at this point are not recognized */
 115         if (argc > 1)
 116                 die("unrecognized argument: %s", argv[1]);
 117
 118         memset(&w, 0, sizeof(w));
 119         userformat_find_requirements(NULL, &w);
 120
 121         if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
 122                 rev->show_notes = 1;
 123         if (rev->show_notes)
 124                 init_display_notes(&rev->notes_opt);
 125
 126         if (rev->diffopt.pickaxe || rev->diffopt.filter)
 127                 rev->always_show_header = 0;
 128         if (DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES)) {
 129                 rev->always_show_header = 0;
 130                 if (rev->diffopt.pathspec.nr != 1)
 131                         usage("git logs can only follow renames on one pathname at a time");
 132         }
 133
 134         if (source)
 135                 rev->show_source = 1;
 136
 137         if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
 138                 /*
 139                  * "log --pretty=raw" is special; ignore UI oriented
 140                  * configuration variables such as decoration.
 141                  */
 142                 if (!decoration_given)
 143                         decoration_style = 0;
 144                 if (!rev->abbrev_commit_given)
 145                         rev->abbrev_commit = 0;
 146         }
 147
 148         if (decoration_style) {
 149                 rev->show_decorations = 1;
 150                 load_ref_decorations(decoration_style);
 151         }
 152         setup_pager();
 153 }
 154
 155 static void cmd_log_init(int argc, const char **argv, const char *prefix,
 156                          struct rev_info *rev, struct setup_revision_opt *opt)
 157 {
 158         cmd_log_init_defaults(rev);
 159         cmd_log_init_finish(argc, argv, prefix, rev, opt);
 160 }
 161
 162 /*
 163  * This gives a rough estimate for how many commits we
 164  * will print out in the list.
 165  */
 166 static int estimate_commit_count(struct rev_info *rev, struct commit_list *list)
 167 {
 168         int n = 0;
 169
 170         while (list) {
 171                 struct commit *commit = list->item;
 172                 unsigned int flags = commit->object.flags;
 173                 list = list->next;
 174                 if (!(flags & (TREESAME | UNINTERESTING)))
 175                         n++;
 176         }
 177         return n;
 178 }
 179
 180 static void show_early_header(struct rev_info *rev, const char *stage, int nr)
 181 {
 182         if (rev->shown_one) {
 183                 rev->shown_one = 0;
 184                 if (rev->commit_format != CMIT_FMT_ONELINE)
 185                         putchar(rev->diffopt.line_termination);
 186         }
 187         printf(_("Final output: %d %s\n"), nr, stage);
 188 }
 189
 190 static struct itimerval early_output_timer;
 191
 192 static void log_show_early(struct rev_info *revs, struct commit_list *list)
 193 {
 194         int i = revs->early_output;
 195         int show_header = 1;
 196
 197         sort_in_topological_order(&list, revs->lifo);
 198         while (list && i) {
 199                 struct commit *commit = list->item;
 200                 switch (simplify_commit(revs, commit)) {
 201                 case commit_show:
 202                         if (show_header) {
 203                                 int n = estimate_commit_count(revs, list);
 204                                 show_early_header(revs, "incomplete", n);
 205                                 show_header = 0;
 206                         }
 207                         log_tree_commit(revs, commit);
 208                         i--;
 209                         break;
 210                 case commit_ignore:
 211                         break;
 212                 case commit_error:
 213                         return;
 214                 }
 215                 list = list->next;
 216         }
 217
 218         /* Did we already get enough commits for the early output? */
 219         if (!i)
 220                 return;
 221
 222         /*
 223          * ..if no, then repeat it twice a second until we
 224          * do.
 225          *
 226          * NOTE! We don't use "it_interval", because if the
 227          * reader isn't listening, we want our output to be
 228          * throttled by the writing, and not have the timer
 229          * trigger every second even if we're blocked on a
 230          * reader!
 231          */
 232         early_output_timer.it_value.tv_sec = 0;
 233         early_output_timer.it_value.tv_usec = 500000;
 234         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 235 }
 236
 237 static void early_output(int signal)
 238 {
 239         show_early_output = log_show_early;
 240 }
 241
 242 static void setup_early_output(struct rev_info *rev)
 243 {
 244         struct sigaction sa;
 245
 246         /*
 247          * Set up the signal handler, minimally intrusively:
 248          * we only set a single volatile integer word (not
 249          * using sigatomic_t - trying to avoid unnecessary
 250          * system dependencies and headers), and using
 251          * SA_RESTART.
 252          */
 253         memset(&sa, 0, sizeof(sa));
 254         sa.sa_handler = early_output;
 255         sigemptyset(&sa.sa_mask);
 256         sa.sa_flags = SA_RESTART;
 257         sigaction(SIGALRM, &sa, NULL);
 258
 259         /*
 260          * If we can get the whole output in less than a
 261          * tenth of a second, don't even bother doing the
 262          * early-output thing..
 263          *
 264          * This is a one-time-only trigger.
 265          */
 266         early_output_timer.it_value.tv_sec = 0;
 267         early_output_timer.it_value.tv_usec = 100000;
 268         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 269 }
 270
 271 static void finish_early_output(struct rev_info *rev)
 272 {
 273         int n = estimate_commit_count(rev, rev->commits);
 274         signal(SIGALRM, SIG_IGN);
 275         show_early_header(rev, "done", n);
 276 }
 277
 278 static int cmd_log_walk(struct rev_info *rev)
 279 {
 280         struct commit *commit;
 281         int saved_nrl = 0;
 282         int saved_dcctc = 0;
 283
 284         if (rev->early_output)
 285                 setup_early_output(rev);
 286
 287         if (prepare_revision_walk(rev))
 288                 die(_("revision walk setup failed"));
 289
 290         if (rev->early_output)
 291                 finish_early_output(rev);
 292
 293         /*
 294          * For --check and --exit-code, the exit code is based on CHECK_FAILED
 295          * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
 296          * retain that state information if replacing rev->diffopt in this loop
 297          */
 298         while ((commit = get_revision(rev)) != NULL) {
 299                 if (!log_tree_commit(rev, commit) &&
 300                     rev->max_count >= 0)
 301                         /*
 302                          * We decremented max_count in get_revision,
 303                          * but we didn't actually show the commit.
 304                          */
 305                         rev->max_count++;
 306                 if (!rev->reflog_info) {
 307                         /* we allow cycles in reflog ancestry */
 308                         free(commit->buffer);
 309                         commit->buffer = NULL;
 310                 }
 311                 free_commit_list(commit->parents);
 312                 commit->parents = NULL;
 313                 if (saved_nrl < rev->diffopt.needed_rename_limit)
 314                         saved_nrl = rev->diffopt.needed_rename_limit;
 315                 if (rev->diffopt.degraded_cc_to_c)
 316                         saved_dcctc = 1;
 317         }
 318         rev->diffopt.degraded_cc_to_c = saved_dcctc;
 319         rev->diffopt.needed_rename_limit = saved_nrl;
 320
 321         if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
 322             DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
 323                 return 02;
 324         }
 325         return diff_result_code(&rev->diffopt, 0);
 326 }
 327
 328 static int git_log_config(const char *var, const char *value, void *cb)
 329 {
 330         if (!strcmp(var, "format.pretty"))
 331                 return git_config_string(&fmt_pretty, var, value);
 332         if (!strcmp(var, "format.subjectprefix"))
 333                 return git_config_string(&fmt_patch_subject_prefix, var, value);
 334         if (!strcmp(var, "log.abbrevcommit")) {
 335                 default_abbrev_commit = git_config_bool(var, value);
 336                 return 0;
 337         }
 338         if (!strcmp(var, "log.date"))
 339                 return git_config_string(&default_date_mode, var, value);
 340         if (!strcmp(var, "log.decorate")) {
 341                 decoration_style = parse_decoration_style(var, value);
 342                 if (decoration_style < 0)
 343                         decoration_style = 0; /* maybe warn? */
 344                 return 0;
 345         }
 346         if (!strcmp(var, "log.showroot")) {
 347                 default_show_root = git_config_bool(var, value);
 348                 return 0;
 349         }
 350         if (!prefixcmp(var, "color.decorate."))
 351                 return parse_decorate_color_config(var, 15, value);
 352
 353         return git_diff_ui_config(var, value, cb);
 354 }
 355
 356 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 357 {
 358         struct rev_info rev;
 359         struct setup_revision_opt opt;
 360
 361         git_config(git_log_config, NULL);
 362
 363         init_revisions(&rev, prefix);
 364         rev.diff = 1;
 365         rev.simplify_history = 0;
 366         memset(&opt, 0, sizeof(opt));
 367         opt.def = "HEAD";
 368         cmd_log_init(argc, argv, prefix, &rev, &opt);
 369         if (!rev.diffopt.output_format)
 370                 rev.diffopt.output_format = DIFF_FORMAT_RAW;
 371         return cmd_log_walk(&rev);
 372 }
 373
 374 static void show_tagger(char *buf, int len, struct rev_info *rev)
 375 {
 376         struct strbuf out = STRBUF_INIT;
 377         struct pretty_print_context pp = {0};
 378
 379         pp.fmt = rev->commit_format;
 380         pp.date_mode = rev->date_mode;
 381         pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
 382         printf("%s", out.buf);
 383         strbuf_release(&out);
 384 }
 385
 386 static int show_object(const unsigned char *sha1, int show_tag_object,
 387         struct rev_info *rev)
 388 {
 389         unsigned long size;
 390         enum object_type type;
 391         char *buf = read_sha1_file(sha1, &type, &size);
 392         int offset = 0;
 393
 394         if (!buf)
 395                 return error(_("Could not read object %s"), sha1_to_hex(sha1));
 396
 397         if (show_tag_object)
 398                 while (offset < size && buf[offset] != '\n') {
 399                         int new_offset = offset + 1;
 400                         while (new_offset < size && buf[new_offset++] != '\n')
 401                                 ; /* do nothing */
 402                         if (!prefixcmp(buf + offset, "tagger "))
 403                                 show_tagger(buf + offset + 7,
 404                                             new_offset - offset - 7, rev);
 405                         offset = new_offset;
 406                 }
 407
 408         if (offset < size)
 409                 fwrite(buf + offset, size - offset, 1, stdout);
 410         free(buf);
 411         return 0;
 412 }
 413
 414 static int show_tree_object(const unsigned char *sha1,
 415                 const char *base, int baselen,
 416                 const char *pathname, unsigned mode, int stage, void *context)
 417 {
 418         printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
 419         return 0;
 420 }
 421
 422 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 423 {
 424         if (rev->ignore_merges) {
 425                 /* There was no "-m" on the command line */
 426                 rev->ignore_merges = 0;
 427                 if (!rev->first_parent_only && !rev->combine_merges) {
 428                         /* No "--first-parent", "-c", nor "--cc" */
 429                         rev->combine_merges = 1;
 430                         rev->dense_combined_merges = 1;
 431                 }
 432         }
 433         if (!rev->diffopt.output_format)
 434                 rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 435 }
 436
 437 int cmd_show(int argc, const char **argv, const char *prefix)
 438 {
 439         struct rev_info rev;
 440         struct object_array_entry *objects;
 441         struct setup_revision_opt opt;
 442         struct pathspec match_all;
 443         int i, count, ret = 0;
 444
 445         git_config(git_log_config, NULL);
 446
 447         init_pathspec(&match_all, NULL);
 448         init_revisions(&rev, prefix);
 449         rev.diff = 1;
 450         rev.always_show_header = 1;
 451         rev.no_walk = 1;
 452         rev.diffopt.stat_width = -1;    /* Scale to real terminal size */
 453
 454         memset(&opt, 0, sizeof(opt));
 455         opt.def = "HEAD";
 456         opt.tweak = show_rev_tweak_rev;
 457         cmd_log_init(argc, argv, prefix, &rev, &opt);
 458
 459         count = rev.pending.nr;
 460         objects = rev.pending.objects;
 461         for (i = 0; i < count && !ret; i++) {
 462                 struct object *o = objects[i].item;
 463                 const char *name = objects[i].name;
 464                 switch (o->type) {
 465                 case OBJ_BLOB:
 466                         ret = show_object(o->sha1, 0, NULL);
 467                         break;
 468                 case OBJ_TAG: {
 469                         struct tag *t = (struct tag *)o;
 470
 471                         if (rev.shown_one)
 472                                 putchar('\n');
 473                         printf("%stag %s%s\n",
 474                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 475                                         t->tag,
 476                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 477                         ret = show_object(o->sha1, 1, &rev);
 478                         rev.shown_one = 1;
 479                         if (ret)
 480                                 break;
 481                         o = parse_object(t->tagged->sha1);
 482                         if (!o)
 483                                 ret = error(_("Could not read object %s"),
 484                                             sha1_to_hex(t->tagged->sha1));
 485                         objects[i].item = o;
 486                         i--;
 487                         break;
 488                 }
 489                 case OBJ_TREE:
 490                         if (rev.shown_one)
 491                                 putchar('\n');
 492                         printf("%stree %s%s\n\n",
 493                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 494                                         name,
 495                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 496                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
 497                                         show_tree_object, NULL);
 498                         rev.shown_one = 1;
 499                         break;
 500                 case OBJ_COMMIT:
 501                         rev.pending.nr = rev.pending.alloc = 0;
 502                         rev.pending.objects = NULL;
 503                         add_object_array(o, name, &rev.pending);
 504                         ret = cmd_log_walk(&rev);
 505                         break;
 506                 default:
 507                         ret = error(_("Unknown type: %d"), o->type);
 508                 }
 509         }
 510         free(objects);
 511         return ret;
 512 }
 513
 514 /*
 515  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 516  */
 517 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 518 {
 519         struct rev_info rev;
 520         struct setup_revision_opt opt;
 521
 522         git_config(git_log_config, NULL);
 523
 524         init_revisions(&rev, prefix);
 525         init_reflog_walk(&rev.reflog_info);
 526         rev.verbose_header = 1;
 527         memset(&opt, 0, sizeof(opt));
 528         opt.def = "HEAD";
 529         cmd_log_init_defaults(&rev);
 530         rev.abbrev_commit = 1;
 531         rev.commit_format = CMIT_FMT_ONELINE;
 532         rev.use_terminator = 1;
 533         rev.always_show_header = 1;
 534         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
 535
 536         return cmd_log_walk(&rev);
 537 }
 538
 539 int cmd_log(int argc, const char **argv, const char *prefix)
 540 {
 541         struct rev_info rev;
 542         struct setup_revision_opt opt;
 543
 544         git_config(git_log_config, NULL);
 545
 546         init_revisions(&rev, prefix);
 547         rev.always_show_header = 1;
 548         memset(&opt, 0, sizeof(opt));
 549         opt.def = "HEAD";
 550         cmd_log_init(argc, argv, prefix, &rev, &opt);
 551         return cmd_log_walk(&rev);
 552 }
 553
 554 /* format-patch */
 555
 556 static const char *fmt_patch_suffix = ".patch";
 557 static int numbered = 0;
 558 static int auto_number = 1;
 559
 560 static char *default_attach = NULL;
 561
 562 static struct string_list extra_hdr;
 563 static struct string_list extra_to;
 564 static struct string_list extra_cc;
 565
 566 static void add_header(const char *value)
 567 {
 568         struct string_list_item *item;
 569         int len = strlen(value);
 570         while (len && value[len - 1] == '\n')
 571                 len--;
 572
 573         if (!strncasecmp(value, "to: ", 4)) {
 574                 item = string_list_append(&extra_to, value + 4);
 575                 len -= 4;
 576         } else if (!strncasecmp(value, "cc: ", 4)) {
 577                 item = string_list_append(&extra_cc, value + 4);
 578                 len -= 4;
 579         } else {
 580                 item = string_list_append(&extra_hdr, value);
 581         }
 582
 583         item->string[len] = '\0';
 584 }
 585
 586 #define THREAD_SHALLOW 1
 587 #define THREAD_DEEP 2
 588 static int thread;
 589 static int do_signoff;
 590 static const char *signature = git_version_string;
 591
 592 static int git_format_config(const char *var, const char *value, void *cb)
 593 {
 594         if (!strcmp(var, "format.headers")) {
 595                 if (!value)
 596                         die(_("format.headers without value"));
 597                 add_header(value);
 598                 return 0;
 599         }
 600         if (!strcmp(var, "format.suffix"))
 601                 return git_config_string(&fmt_patch_suffix, var, value);
 602         if (!strcmp(var, "format.to")) {
 603                 if (!value)
 604                         return config_error_nonbool(var);
 605                 string_list_append(&extra_to, value);
 606                 return 0;
 607         }
 608         if (!strcmp(var, "format.cc")) {
 609                 if (!value)
 610                         return config_error_nonbool(var);
 611                 string_list_append(&extra_cc, value);
 612                 return 0;
 613         }
 614         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
 615             !strcmp(var, "color.ui")) {
 616                 return 0;
 617         }
 618         if (!strcmp(var, "format.numbered")) {
 619                 if (value && !strcasecmp(value, "auto")) {
 620                         auto_number = 1;
 621                         return 0;
 622                 }
 623                 numbered = git_config_bool(var, value);
 624                 auto_number = auto_number && numbered;
 625                 return 0;
 626         }
 627         if (!strcmp(var, "format.attach")) {
 628                 if (value && *value)
 629                         default_attach = xstrdup(value);
 630                 else
 631                         default_attach = xstrdup(git_version_string);
 632                 return 0;
 633         }
 634         if (!strcmp(var, "format.thread")) {
 635                 if (value && !strcasecmp(value, "deep")) {
 636                         thread = THREAD_DEEP;
 637                         return 0;
 638                 }
 639                 if (value && !strcasecmp(value, "shallow")) {
 640                         thread = THREAD_SHALLOW;
 641                         return 0;
 642                 }
 643                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
 644                 return 0;
 645         }
 646         if (!strcmp(var, "format.signoff")) {
 647                 do_signoff = git_config_bool(var, value);
 648                 return 0;
 649         }
 650         if (!strcmp(var, "format.signature"))
 651                 return git_config_string(&signature, var, value);
 652
 653         return git_log_config(var, value, cb);
 654 }
 655
 656 static FILE *realstdout = NULL;
 657 static const char *output_directory = NULL;
 658 static int outdir_offset;
 659
 660 static int reopen_stdout(struct commit *commit, struct rev_info *rev, int quiet)
 661 {
 662         struct strbuf filename = STRBUF_INIT;
 663         int suffix_len = strlen(fmt_patch_suffix) + 1;
 664
 665         if (output_directory) {
 666                 strbuf_addstr(&filename, output_directory);
 667                 if (filename.len >=
 668                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
 669                         return error(_("name of output directory is too long"));
 670                 if (filename.buf[filename.len - 1] != '/')
 671                         strbuf_addch(&filename, '/');
 672         }
 673
 674         get_patch_filename(commit, rev->nr, fmt_patch_suffix, &filename);
 675
 676         if (!quiet)
 677                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
 678
 679         if (freopen(filename.buf, "w", stdout) == NULL)
 680                 return error(_("Cannot open patch file %s"), filename.buf);
 681
 682         strbuf_release(&filename);
 683         return 0;
 684 }
 685
 686 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
 687 {
 688         struct rev_info check_rev;
 689         struct commit *commit;
 690         struct object *o1, *o2;
 691         unsigned flags1, flags2;
 692
 693         if (rev->pending.nr != 2)
 694                 die(_("Need exactly one range."));
 695
 696         o1 = rev->pending.objects[0].item;
 697         flags1 = o1->flags;
 698         o2 = rev->pending.objects[1].item;
 699         flags2 = o2->flags;
 700
 701         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 702                 die(_("Not a range."));
 703
 704         init_patch_ids(ids);
 705
 706         /* given a range a..b get all patch ids for b..a */
 707         init_revisions(&check_rev, prefix);
 708         o1->flags ^= UNINTERESTING;
 709         o2->flags ^= UNINTERESTING;
 710         add_pending_object(&check_rev, o1, "o1");
 711         add_pending_object(&check_rev, o2, "o2");
 712         if (prepare_revision_walk(&check_rev))
 713                 die(_("revision walk setup failed"));
 714
 715         while ((commit = get_revision(&check_rev)) != NULL) {
 716                 /* ignore merges */
 717                 if (commit->parents && commit->parents->next)
 718                         continue;
 719
 720                 add_commit_patch_id(commit, ids);
 721         }
 722
 723         /* reset for next revision walk */
 724         clear_commit_marks((struct commit *)o1,
 725                         SEEN | UNINTERESTING | SHOWN | ADDED);
 726         clear_commit_marks((struct commit *)o2,
 727                         SEEN | UNINTERESTING | SHOWN | ADDED);
 728         o1->flags = flags1;
 729         o2->flags = flags2;
 730 }
 731
 732 static void gen_message_id(struct rev_info *info, char *base)
 733 {
 734         const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 735         const char *email_start = strrchr(committer, '<');
 736         const char *email_end = strrchr(committer, '>');
 737         struct strbuf buf = STRBUF_INIT;
 738         if (!email_start || !email_end || email_start > email_end - 1)
 739                 die(_("Could not extract email from committer identity."));
 740         strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
 741                     (unsigned long) time(NULL),
 742                     (int)(email_end - email_start - 1), email_start + 1);
 743         info->message_id = strbuf_detach(&buf, NULL);
 744 }
 745
 746 static void print_signature(void)
 747 {
 748         if (signature && *signature)
 749                 printf("-- \n%s\n\n", signature);
 750 }
 751
 752 static void add_branch_description(struct strbuf *buf, const char *branch_name)
 753 {
 754         struct strbuf desc = STRBUF_INIT;
 755         if (!branch_name || !*branch_name)
 756                 return;
 757         read_branch_desc(&desc, branch_name);
 758         if (desc.len) {
 759                 strbuf_addch(buf, '\n');
 760                 strbuf_add(buf, desc.buf, desc.len);
 761                 strbuf_addch(buf, '\n');
 762         }
 763 }
 764
 765 static void make_cover_letter(struct rev_info *rev, int use_stdout,
 766                               int numbered, int numbered_files,
 767                               struct commit *origin,
 768                               int nr, struct commit **list, struct commit *head,
 769                               const char *branch_name,
 770                               int quiet)
 771 {
 772         const char *committer;
 773         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
 774         const char *msg;
 775         struct shortlog log;
 776         struct strbuf sb = STRBUF_INIT;
 777         int i;
 778         const char *encoding = "UTF-8";
 779         struct diff_options opts;
 780         int need_8bit_cte = 0;
 781         struct commit *commit = NULL;
 782         struct pretty_print_context pp = {0};
 783
 784         if (rev->commit_format != CMIT_FMT_EMAIL)
 785                 die(_("Cover letter needs email format"));
 786
 787         committer = git_committer_info(0);
 788
 789         if (!numbered_files) {
 790                 /*
 791                  * We fake a commit for the cover letter so we get the filename
 792                  * desired.
 793                  */
 794                 commit = xcalloc(1, sizeof(*commit));
 795                 commit->buffer = xmalloc(400);
 796                 snprintf(commit->buffer, 400,
 797                         "tree 0000000000000000000000000000000000000000\n"
 798                         "parent %s\n"
 799                         "author %s\n"
 800                         "committer %s\n\n"
 801                         "cover letter\n",
 802                         sha1_to_hex(head->object.sha1), committer, committer);
 803         }
 804
 805         if (!use_stdout && reopen_stdout(commit, rev, quiet))
 806                 return;
 807
 808         if (commit) {
 809
 810                 free(commit->buffer);
 811                 free(commit);
 812         }
 813
 814         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
 815                                 &need_8bit_cte);
 816
 817         for (i = 0; !need_8bit_cte && i < nr; i++)
 818                 if (has_non_ascii(list[i]->buffer))
 819                         need_8bit_cte = 1;
 820
 821         msg = body;
 822         pp.fmt = CMIT_FMT_EMAIL;
 823         pp.date_mode = DATE_RFC2822;
 824         pp_user_info(&pp, NULL, &sb, committer, encoding);
 825         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 826         pp_remainder(&pp, &msg, &sb, 0);
 827         add_branch_description(&sb, branch_name);
 828         printf("%s\n", sb.buf);
 829
 830         strbuf_release(&sb);
 831
 832         shortlog_init(&log);
 833         log.wrap_lines = 1;
 834         log.wrap = 72;
 835         log.in1 = 2;
 836         log.in2 = 4;
 837         for (i = 0; i < nr; i++)
 838                 shortlog_add_commit(&log, list[i]);
 839
 840         shortlog_output(&log);
 841
 842         /*
 843          * We can only do diffstat with a unique reference point
 844          */
 845         if (!origin)
 846                 return;
 847
 848         memcpy(&opts, &rev->diffopt, sizeof(opts));
 849         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 850
 851         diff_setup_done(&opts);
 852
 853         diff_tree_sha1(origin->tree->object.sha1,
 854                        head->tree->object.sha1,
 855                        "", &opts);
 856         diffcore_std(&opts);
 857         diff_flush(&opts);
 858
 859         printf("\n");
 860         print_signature();
 861 }
 862
 863 static const char *clean_message_id(const char *msg_id)
 864 {
 865         char ch;
 866         const char *a, *z, *m;
 867
 868         m = msg_id;
 869         while ((ch = *m) && (isspace(ch) || (ch == '<')))
 870                 m++;
 871         a = m;
 872         z = NULL;
 873         while ((ch = *m)) {
 874                 if (!isspace(ch) && (ch != '>'))
 875                         z = m;
 876                 m++;
 877         }
 878         if (!z)
 879                 die(_("insane in-reply-to: %s"), msg_id);
 880         if (++z == m)
 881                 return a;
 882         return xmemdupz(a, z - a);
 883 }
 884
 885 static const char *set_outdir(const char *prefix, const char *output_directory)
 886 {
 887         if (output_directory && is_absolute_path(output_directory))
 888                 return output_directory;
 889
 890         if (!prefix || !*prefix) {
 891                 if (output_directory)
 892                         return output_directory;
 893                 /* The user did not explicitly ask for "./" */
 894                 outdir_offset = 2;
 895                 return "./";
 896         }
 897
 898         outdir_offset = strlen(prefix);
 899         if (!output_directory)
 900                 return prefix;
 901
 902         return xstrdup(prefix_filename(prefix, outdir_offset,
 903                                        output_directory));
 904 }
 905
 906 static const char * const builtin_format_patch_usage[] = {
 907         "git format-patch [options] [<since> | <revision range>]",
 908         NULL
 909 };
 910
 911 static int keep_subject = 0;
 912
 913 static int keep_callback(const struct option *opt, const char *arg, int unset)
 914 {
 915         ((struct rev_info *)opt->value)->total = -1;
 916         keep_subject = 1;
 917         return 0;
 918 }
 919
 920 static int subject_prefix = 0;
 921
 922 static int subject_prefix_callback(const struct option *opt, const char *arg,
 923                             int unset)
 924 {
 925         subject_prefix = 1;
 926         ((struct rev_info *)opt->value)->subject_prefix = arg;
 927         return 0;
 928 }
 929
 930 static int numbered_cmdline_opt = 0;
 931
 932 static int numbered_callback(const struct option *opt, const char *arg,
 933                              int unset)
 934 {
 935         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 936         if (unset)
 937                 auto_number =  0;
 938         return 0;
 939 }
 940
 941 static int no_numbered_callback(const struct option *opt, const char *arg,
 942                                 int unset)
 943 {
 944         return numbered_callback(opt, arg, 1);
 945 }
 946
 947 static int output_directory_callback(const struct option *opt, const char *arg,
 948                               int unset)
 949 {
 950         const char **dir = (const char **)opt->value;
 951         if (*dir)
 952                 die(_("Two output directories?"));
 953         *dir = arg;
 954         return 0;
 955 }
 956
 957 static int thread_callback(const struct option *opt, const char *arg, int unset)
 958 {
 959         int *thread = (int *)opt->value;
 960         if (unset)
 961                 *thread = 0;
 962         else if (!arg || !strcmp(arg, "shallow"))
 963                 *thread = THREAD_SHALLOW;
 964         else if (!strcmp(arg, "deep"))
 965                 *thread = THREAD_DEEP;
 966         else
 967                 return 1;
 968         return 0;
 969 }
 970
 971 static int attach_callback(const struct option *opt, const char *arg, int unset)
 972 {
 973         struct rev_info *rev = (struct rev_info *)opt->value;
 974         if (unset)
 975                 rev->mime_boundary = NULL;
 976         else if (arg)
 977                 rev->mime_boundary = arg;
 978         else
 979                 rev->mime_boundary = git_version_string;
 980         rev->no_inline = unset ? 0 : 1;
 981         return 0;
 982 }
 983
 984 static int inline_callback(const struct option *opt, const char *arg, int unset)
 985 {
 986         struct rev_info *rev = (struct rev_info *)opt->value;
 987         if (unset)
 988                 rev->mime_boundary = NULL;
 989         else if (arg)
 990                 rev->mime_boundary = arg;
 991         else
 992                 rev->mime_boundary = git_version_string;
 993         rev->no_inline = 0;
 994         return 0;
 995 }
 996
 997 static int header_callback(const struct option *opt, const char *arg, int unset)
 998 {
 999         if (unset) {
1000                 string_list_clear(&extra_hdr, 0);
1001                 string_list_clear(&extra_to, 0);
1002                 string_list_clear(&extra_cc, 0);
1003         } else {
1004             add_header(arg);
1005         }
1006         return 0;
1007 }
1008
1009 static int to_callback(const struct option *opt, const char *arg, int unset)
1010 {
1011         if (unset)
1012                 string_list_clear(&extra_to, 0);
1013         else
1014                 string_list_append(&extra_to, arg);
1015         return 0;
1016 }
1017
1018 static int cc_callback(const struct option *opt, const char *arg, int unset)
1019 {
1020         if (unset)
1021                 string_list_clear(&extra_cc, 0);
1022         else
1023                 string_list_append(&extra_cc, arg);
1024         return 0;
1025 }
1026
1027 static char *find_branch_name(struct rev_info *rev)
1028 {
1029         int i, positive = -1;
1030         unsigned char branch_sha1[20];
1031         struct strbuf buf = STRBUF_INIT;
1032         const char *branch;
1033
1034         for (i = 0; i < rev->cmdline.nr; i++) {
1035                 if (rev->cmdline.rev[i].flags & UNINTERESTING)
1036                         continue;
1037                 if (positive < 0)
1038                         positive = i;
1039                 else
1040                         return NULL;
1041         }
1042         if (positive < 0)
1043                 return NULL;
1044         strbuf_addf(&buf, "refs/heads/%s", rev->cmdline.rev[positive].name);
1045         branch = resolve_ref_unsafe(buf.buf, branch_sha1, 1, NULL);
1046         if (!branch ||
1047             prefixcmp(branch, "refs/heads/") ||
1048             hashcmp(rev->cmdline.rev[positive].item->sha1, branch_sha1))
1049                 branch = NULL;
1050         strbuf_release(&buf);
1051         if (branch)
1052                 return xstrdup(rev->cmdline.rev[positive].name);
1053         return NULL;
1054 }
1055
1056 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1057 {
1058         struct commit *commit;
1059         struct commit **list = NULL;
1060         struct rev_info rev;
1061         struct setup_revision_opt s_r_opt;
1062         int nr = 0, total, i;
1063         int use_stdout = 0;
1064         int start_number = -1;
1065         int numbered_files = 0;         /* _just_ numbers */
1066         int ignore_if_in_upstream = 0;
1067         int cover_letter = 0;
1068         int boundary_count = 0;
1069         int no_binary_diff = 0;
1070         struct commit *origin = NULL, *head = NULL;
1071         const char *in_reply_to = NULL;
1072         struct patch_ids ids;
1073         char *add_signoff = NULL;
1074         struct strbuf buf = STRBUF_INIT;
1075         int use_patch_format = 0;
1076         int quiet = 0;
1077         char *branch_name = NULL;
1078         const struct option builtin_format_patch_options[] = {
1079                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1080                             "use [PATCH n/m] even with a single patch",
1081                             PARSE_OPT_NOARG, numbered_callback },
1082                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1083                             "use [PATCH] even with multiple patches",
1084                             PARSE_OPT_NOARG, no_numbered_callback },
1085                 OPT_BOOLEAN('s', "signoff", &do_signoff, "add Signed-off-by:"),
1086                 OPT_BOOLEAN(0, "stdout", &use_stdout,
1087                             "print patches to standard out"),
1088                 OPT_BOOLEAN(0, "cover-letter", &cover_letter,
1089                             "generate a cover letter"),
1090                 OPT_BOOLEAN(0, "numbered-files", &numbered_files,
1091                             "use simple number sequence for output file names"),
1092                 OPT_STRING(0, "suffix", &fmt_patch_suffix, "sfx",
1093                             "use <sfx> instead of '.patch'"),
1094                 OPT_INTEGER(0, "start-number", &start_number,
1095                             "start numbering patches at <n> instead of 1"),
1096                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, "prefix",
1097                             "Use [<prefix>] instead of [PATCH]",
1098                             PARSE_OPT_NONEG, subject_prefix_callback },
1099                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1100                             "dir", "store resulting files in <dir>",
1101                             PARSE_OPT_NONEG, output_directory_callback },
1102                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1103                             "don't strip/add [PATCH]",
1104                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1105                 OPT_BOOLEAN(0, "no-binary", &no_binary_diff,
1106                             "don't output binary diffs"),
1107                 OPT_BOOLEAN(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1108                             "don't include a patch matching a commit upstream"),
1109                 { OPTION_BOOLEAN, 'p', "no-stat", &use_patch_format, NULL,
1110                   "show patch format instead of default (patch + stat)",
1111                   PARSE_OPT_NONEG | PARSE_OPT_NOARG },
1112                 OPT_GROUP("Messaging"),
1113                 { OPTION_CALLBACK, 0, "add-header", NULL, "header",
1114                             "add email header", 0, header_callback },
1115                 { OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
1116                             0, to_callback },
1117                 { OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
1118                             0, cc_callback },
1119                 OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
1120                             "make first mail a reply to <message-id>"),
1121                 { OPTION_CALLBACK, 0, "attach", &rev, "boundary",
1122                             "attach the patch", PARSE_OPT_OPTARG,
1123                             attach_callback },
1124                 { OPTION_CALLBACK, 0, "inline", &rev, "boundary",
1125                             "inline the patch",
1126                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1127                             inline_callback },
1128                 { OPTION_CALLBACK, 0, "thread", &thread, "style",
1129                             "enable message threading, styles: shallow, deep",
1130                             PARSE_OPT_OPTARG, thread_callback },
1131                 OPT_STRING(0, "signature", &signature, "signature",
1132                             "add a signature"),
1133                 OPT_BOOLEAN(0, "quiet", &quiet,
1134                             "don't print the patch filenames"),
1135                 OPT_END()
1136         };
1137
1138         extra_hdr.strdup_strings = 1;
1139         extra_to.strdup_strings = 1;
1140         extra_cc.strdup_strings = 1;
1141         git_config(git_format_config, NULL);
1142         init_revisions(&rev, prefix);
1143         rev.commit_format = CMIT_FMT_EMAIL;
1144         rev.verbose_header = 1;
1145         rev.diff = 1;
1146         rev.max_parents = 1;
1147         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1148         rev.subject_prefix = fmt_patch_subject_prefix;
1149         memset(&s_r_opt, 0, sizeof(s_r_opt));
1150         s_r_opt.def = "HEAD";
1151
1152         if (default_attach) {
1153                 rev.mime_boundary = default_attach;
1154                 rev.no_inline = 1;
1155         }
1156
1157         /*
1158          * Parse the arguments before setup_revisions(), or something
1159          * like "git format-patch -o a123 HEAD^.." may fail; a123 is
1160          * possibly a valid SHA1.
1161          */
1162         argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
1163                              builtin_format_patch_usage,
1164                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
1165                              PARSE_OPT_KEEP_DASHDASH);
1166
1167         if (do_signoff) {
1168                 const char *committer;
1169                 const char *endpos;
1170                 committer = git_committer_info(IDENT_ERROR_ON_NO_NAME);
1171                 endpos = strchr(committer, '>');
1172                 if (!endpos)
1173                         die(_("bogus committer info %s"), committer);
1174                 add_signoff = xmemdupz(committer, endpos - committer + 1);
1175         }
1176
1177         for (i = 0; i < extra_hdr.nr; i++) {
1178                 strbuf_addstr(&buf, extra_hdr.items[i].string);
1179                 strbuf_addch(&buf, '\n');
1180         }
1181
1182         if (extra_to.nr)
1183                 strbuf_addstr(&buf, "To: ");
1184         for (i = 0; i < extra_to.nr; i++) {
1185                 if (i)
1186                         strbuf_addstr(&buf, "    ");
1187                 strbuf_addstr(&buf, extra_to.items[i].string);
1188                 if (i + 1 < extra_to.nr)
1189                         strbuf_addch(&buf, ',');
1190                 strbuf_addch(&buf, '\n');
1191         }
1192
1193         if (extra_cc.nr)
1194                 strbuf_addstr(&buf, "Cc: ");
1195         for (i = 0; i < extra_cc.nr; i++) {
1196                 if (i)
1197                         strbuf_addstr(&buf, "    ");
1198                 strbuf_addstr(&buf, extra_cc.items[i].string);
1199                 if (i + 1 < extra_cc.nr)
1200                         strbuf_addch(&buf, ',');
1201                 strbuf_addch(&buf, '\n');
1202         }
1203
1204         rev.extra_headers = strbuf_detach(&buf, NULL);
1205
1206         if (start_number < 0)
1207                 start_number = 1;
1208
1209         /*
1210          * If numbered is set solely due to format.numbered in config,
1211          * and it would conflict with --keep-subject (-k) from the
1212          * command line, reset "numbered".
1213          */
1214         if (numbered && keep_subject && !numbered_cmdline_opt)
1215                 numbered = 0;
1216
1217         if (numbered && keep_subject)
1218                 die (_("-n and -k are mutually exclusive."));
1219         if (keep_subject && subject_prefix)
1220                 die (_("--subject-prefix and -k are mutually exclusive."));
1221         rev.preserve_subject = keep_subject;
1222
1223         argc = setup_revisions(argc, argv, &rev, &s_r_opt);
1224         if (argc > 1)
1225                 die (_("unrecognized argument: %s"), argv[1]);
1226
1227         if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
1228                 die(_("--name-only does not make sense"));
1229         if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
1230                 die(_("--name-status does not make sense"));
1231         if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
1232                 die(_("--check does not make sense"));
1233
1234         if (!use_patch_format &&
1235                 (!rev.diffopt.output_format ||
1236                  rev.diffopt.output_format == DIFF_FORMAT_PATCH))
1237                 rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
1238
1239         /* Always generate a patch */
1240         rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
1241
1242         if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
1243                 DIFF_OPT_SET(&rev.diffopt, BINARY);
1244
1245         if (rev.show_notes)
1246                 init_display_notes(&rev.notes_opt);
1247
1248         if (!use_stdout)
1249                 output_directory = set_outdir(prefix, output_directory);
1250         else
1251                 setup_pager();
1252
1253         if (output_directory) {
1254                 if (use_stdout)
1255                         die(_("standard output, or directory, which one?"));
1256                 if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
1257                         die_errno(_("Could not create directory '%s'"),
1258                                   output_directory);
1259         }
1260
1261         if (rev.pending.nr == 1) {
1262                 if (rev.max_count < 0 && !rev.show_root_diff) {
1263                         /*
1264                          * This is traditional behaviour of "git format-patch
1265                          * origin" that prepares what the origin side still
1266                          * does not have.
1267                          */
1268                         unsigned char sha1[20];
1269                         const char *ref;
1270
1271                         rev.pending.objects[0].item->flags |= UNINTERESTING;
1272                         add_head_to_pending(&rev);
1273                         ref = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
1274                         if (ref && !prefixcmp(ref, "refs/heads/"))
1275                                 branch_name = xstrdup(ref + strlen("refs/heads/"));
1276                         else
1277                                 branch_name = xstrdup(""); /* no branch */
1278                 }
1279                 /*
1280                  * Otherwise, it is "format-patch -22 HEAD", and/or
1281                  * "format-patch --root HEAD".  The user wants
1282                  * get_revision() to do the usual traversal.
1283                  */
1284         }
1285
1286         /*
1287          * We cannot move this anywhere earlier because we do want to
1288          * know if --root was given explicitly from the command line.
1289          */
1290         rev.show_root_diff = 1;
1291
1292         if (cover_letter) {
1293                 /*
1294                  * NEEDSWORK:randomly pick one positive commit to show
1295                  * diffstat; this is often the tip and the command
1296                  * happens to do the right thing in most cases, but a
1297                  * complex command like "--cover-letter a b c ^bottom"
1298                  * picks "c" and shows diffstat between bottom..c
1299                  * which may not match what the series represents at
1300                  * all and totally broken.
1301                  */
1302                 int i;
1303                 for (i = 0; i < rev.pending.nr; i++) {
1304                         struct object *o = rev.pending.objects[i].item;
1305                         if (!(o->flags & UNINTERESTING))
1306                                 head = (struct commit *)o;
1307                 }
1308                 /* There is nothing to show; it is not an error, though. */
1309                 if (!head)
1310                         return 0;
1311                 if (!branch_name)
1312                         branch_name = find_branch_name(&rev);
1313         }
1314
1315         if (ignore_if_in_upstream) {
1316                 /* Don't say anything if head and upstream are the same. */
1317                 if (rev.pending.nr == 2) {
1318                         struct object_array_entry *o = rev.pending.objects;
1319                         if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1320                                 return 0;
1321                 }
1322                 get_patch_ids(&rev, &ids, prefix);
1323         }
1324
1325         if (!use_stdout)
1326                 realstdout = xfdopen(xdup(1), "w");
1327
1328         if (prepare_revision_walk(&rev))
1329                 die(_("revision walk setup failed"));
1330         rev.boundary = 1;
1331         while ((commit = get_revision(&rev)) != NULL) {
1332                 if (commit->object.flags & BOUNDARY) {
1333                         boundary_count++;
1334                         origin = (boundary_count == 1) ? commit : NULL;
1335                         continue;
1336                 }
1337
1338                 if (ignore_if_in_upstream &&
1339                                 has_commit_patch_id(commit, &ids))
1340                         continue;
1341
1342                 nr++;
1343                 list = xrealloc(list, nr * sizeof(list[0]));
1344                 list[nr - 1] = commit;
1345         }
1346         total = nr;
1347         if (!keep_subject && auto_number && total > 1)
1348                 numbered = 1;
1349         if (numbered)
1350                 rev.total = total + start_number - 1;
1351         if (in_reply_to || thread || cover_letter)
1352                 rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
1353         if (in_reply_to) {
1354                 const char *msgid = clean_message_id(in_reply_to);
1355                 string_list_append(rev.ref_message_ids, msgid);
1356         }
1357         rev.numbered_files = numbered_files;
1358         rev.patch_suffix = fmt_patch_suffix;
1359         if (cover_letter) {
1360                 if (thread)
1361                         gen_message_id(&rev, "cover");
1362                 make_cover_letter(&rev, use_stdout, numbered, numbered_files,
1363                                   origin, nr, list, head, branch_name, quiet);
1364                 total++;
1365                 start_number--;
1366         }
1367         rev.add_signoff = add_signoff;
1368         while (0 <= --nr) {
1369                 int shown;
1370                 commit = list[nr];
1371                 rev.nr = total - nr + (start_number - 1);
1372                 /* Make the second and subsequent mails replies to the first */
1373                 if (thread) {
1374                         /* Have we already had a message ID? */
1375                         if (rev.message_id) {
1376                                 /*
1377                                  * For deep threading: make every mail
1378                                  * a reply to the previous one, no
1379                                  * matter what other options are set.
1380                                  *
1381                                  * For shallow threading:
1382                                  *
1383                                  * Without --cover-letter and
1384                                  * --in-reply-to, make every mail a
1385                                  * reply to the one before.
1386                                  *
1387                                  * With --in-reply-to but no
1388                                  * --cover-letter, make every mail a
1389                                  * reply to the <reply-to>.
1390                                  *
1391                                  * With --cover-letter, make every
1392                                  * mail but the cover letter a reply
1393                                  * to the cover letter.  The cover
1394                                  * letter is a reply to the
1395                                  * --in-reply-to, if specified.
1396                                  */
1397                                 if (thread == THREAD_SHALLOW
1398                                     && rev.ref_message_ids->nr > 0
1399                                     && (!cover_letter || rev.nr > 1))
1400                                         free(rev.message_id);
1401                                 else
1402                                         string_list_append(rev.ref_message_ids,
1403                                                            rev.message_id);
1404                         }
1405                         gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
1406                 }
1407
1408                 if (!use_stdout && reopen_stdout(numbered_files ? NULL : commit,
1409                                                  &rev, quiet))
1410                         die(_("Failed to create output files"));
1411                 shown = log_tree_commit(&rev, commit);
1412                 free(commit->buffer);
1413                 commit->buffer = NULL;
1414
1415                 /* We put one extra blank line between formatted
1416                  * patches and this flag is used by log-tree code
1417                  * to see if it needs to emit a LF before showing
1418                  * the log; when using one file per patch, we do
1419                  * not want the extra blank line.
1420                  */
1421                 if (!use_stdout)
1422                         rev.shown_one = 0;
1423                 if (shown) {
1424                         if (rev.mime_boundary)
1425                                 printf("\n--%s%s--\n\n\n",
1426                                        mime_boundary_leader,
1427                                        rev.mime_boundary);
1428                         else
1429                                 print_signature();
1430                 }
1431                 if (!use_stdout)
1432                         fclose(stdout);
1433         }
1434         free(list);
1435         free(branch_name);
1436         string_list_clear(&extra_to, 0);
1437         string_list_clear(&extra_cc, 0);
1438         string_list_clear(&extra_hdr, 0);
1439         if (ignore_if_in_upstream)
1440                 free_patch_ids(&ids);
1441         return 0;
1442 }
1443
1444 static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
1445 {
1446         unsigned char sha1[20];
1447         if (get_sha1(arg, sha1) == 0) {
1448                 struct commit *commit = lookup_commit_reference(sha1);
1449                 if (commit) {
1450                         commit->object.flags |= flags;
1451                         add_pending_object(revs, &commit->object, arg);
1452                         return 0;
1453                 }
1454         }
1455         return -1;
1456 }
1457
1458 static const char * const cherry_usage[] = {
1459         "git cherry [-v] [<upstream> [<head> [<limit>]]]",
1460         NULL
1461 };
1462
1463 static void print_commit(char sign, struct commit *commit, int verbose,
1464                          int abbrev)
1465 {
1466         if (!verbose) {
1467                 printf("%c %s\n", sign,
1468                        find_unique_abbrev(commit->object.sha1, abbrev));
1469         } else {
1470                 struct strbuf buf = STRBUF_INIT;
1471                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
1472                 printf("%c %s %s\n", sign,
1473                        find_unique_abbrev(commit->object.sha1, abbrev),
1474                        buf.buf);
1475                 strbuf_release(&buf);
1476         }
1477 }
1478
1479 int cmd_cherry(int argc, const char **argv, const char *prefix)
1480 {
1481         struct rev_info revs;
1482         struct patch_ids ids;
1483         struct commit *commit;
1484         struct commit_list *list = NULL;
1485         struct branch *current_branch;
1486         const char *upstream;
1487         const char *head = "HEAD";
1488         const char *limit = NULL;
1489         int verbose = 0, abbrev = 0;
1490
1491         struct option options[] = {
1492                 OPT__ABBREV(&abbrev),
1493                 OPT__VERBOSE(&verbose, "be verbose"),
1494                 OPT_END()
1495         };
1496
1497         argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);
1498
1499         switch (argc) {
1500         case 3:
1501                 limit = argv[2];
1502                 /* FALLTHROUGH */
1503         case 2:
1504                 head = argv[1];
1505                 /* FALLTHROUGH */
1506         case 1:
1507                 upstream = argv[0];
1508                 break;
1509         default:
1510                 current_branch = branch_get(NULL);
1511                 if (!current_branch || !current_branch->merge
1512                                         || !current_branch->merge[0]
1513                                         || !current_branch->merge[0]->dst) {
1514                         fprintf(stderr, _("Could not find a tracked"
1515                                         " remote branch, please"
1516                                         " specify <upstream> manually.\n"));
1517                         usage_with_options(cherry_usage, options);
1518                 }
1519
1520                 upstream = current_branch->merge[0]->dst;
1521         }
1522
1523         init_revisions(&revs, prefix);
1524         revs.diff = 1;
1525         revs.combine_merges = 0;
1526         revs.ignore_merges = 1;
1527         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
1528
1529         if (add_pending_commit(head, &revs, 0))
1530                 die(_("Unknown commit %s"), head);
1531         if (add_pending_commit(upstream, &revs, UNINTERESTING))
1532                 die(_("Unknown commit %s"), upstream);
1533
1534         /* Don't say anything if head and upstream are the same. */
1535         if (revs.pending.nr == 2) {
1536                 struct object_array_entry *o = revs.pending.objects;
1537                 if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1538                         return 0;
1539         }
1540
1541         get_patch_ids(&revs, &ids, prefix);
1542
1543         if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
1544                 die(_("Unknown commit %s"), limit);
1545
1546         /* reverse the list of commits */
1547         if (prepare_revision_walk(&revs))
1548                 die(_("revision walk setup failed"));
1549         while ((commit = get_revision(&revs)) != NULL) {
1550                 /* ignore merges */
1551                 if (commit->parents && commit->parents->next)
1552                         continue;
1553
1554                 commit_list_insert(commit, &list);
1555         }
1556
1557         while (list) {
1558                 char sign = '+';
1559
1560                 commit = list->item;
1561                 if (has_commit_patch_id(commit, &ids))
1562                         sign = '-';
1563                 print_commit(sign, commit, verbose, abbrev);
1564                 list = list->next;
1565         }
1566
1567         free_patch_ids(&ids);
1568         return 0;
1569 }