builtin/log.c

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