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