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