builtin/log.c

   1 /*
   2  * Builtin "git log" and related commands (show, whatchanged)
   3  *
   4  * (C) Copyright 2006 Linus Torvalds
   5  *               2006 Junio Hamano
   6  */
   7 #include "cache.h"
   8 #include "color.h"
   9 #include "commit.h"
  10 #include "diff.h"
  11 #include "revision.h"
  12 #include "log-tree.h"
  13 #include "builtin.h"
  14 #include "tag.h"
  15 #include "reflog-walk.h"
  16 #include "patch-ids.h"
  17 #include "run-command.h"
  18 #include "shortlog.h"
  19 #include "remote.h"
  20 #include "string-list.h"
  21 #include "parse-options.h"
  22 #include "branch.h"
  23
  24 /* Set a default date-time format for git log ("log.date" config variable) */
  25 static const char *default_date_mode = NULL;
  26
  27 static int default_abbrev_commit;
  28 static int default_show_root = 1;
  29 static int decoration_style;
  30 static int decoration_given;
  31 static const char *fmt_patch_subject_prefix = "PATCH";
  32 static const char *fmt_pretty;
  33
  34 static const char * const builtin_log_usage[] = {
  35         "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
  36         "   or: git show [options] <object>...",
  37         NULL
  38 };
  39
  40 static int parse_decoration_style(const char *var, const char *value)
  41 {
  42         switch (git_config_maybe_bool(var, value)) {
  43         case 1:
  44                 return DECORATE_SHORT_REFS;
  45         case 0:
  46                 return 0;
  47         default:
  48                 break;
  49         }
  50         if (!strcmp(value, "full"))
  51                 return DECORATE_FULL_REFS;
  52         else if (!strcmp(value, "short"))
  53                 return DECORATE_SHORT_REFS;
  54         return -1;
  55 }
  56
  57 static int decorate_callback(const struct option *opt, const char *arg, int unset)
  58 {
  59         if (unset)
  60                 decoration_style = 0;
  61         else if (arg)
  62                 decoration_style = parse_decoration_style("command line", arg);
  63         else
  64                 decoration_style = DECORATE_SHORT_REFS;
  65
  66         if (decoration_style < 0)
  67                 die("invalid --decorate option: %s", arg);
  68
  69         decoration_given = 1;
  70
  71         return 0;
  72 }
  73
  74 static void cmd_log_init_defaults(struct rev_info *rev)
  75 {
  76         if (fmt_pretty)
  77                 get_commit_format(fmt_pretty, rev);
  78         rev->verbose_header = 1;
  79         DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
  80         rev->diffopt.stat_width = -1; /* use full terminal width */
  81         rev->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         init_revisions(&rev, prefix);
 363         rev.diff = 1;
 364         rev.simplify_history = 0;
 365         memset(&opt, 0, sizeof(opt));
 366         opt.def = "HEAD";
 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         rev.diffopt.stat_width = -1;    /* Scale to real terminal size */
 452
 453         memset(&opt, 0, sizeof(opt));
 454         opt.def = "HEAD";
 455         opt.tweak = show_rev_tweak_rev;
 456         cmd_log_init(argc, argv, prefix, &rev, &opt);
 457
 458         count = rev.pending.nr;
 459         objects = rev.pending.objects;
 460         for (i = 0; i < count && !ret; i++) {
 461                 struct object *o = objects[i].item;
 462                 const char *name = objects[i].name;
 463                 switch (o->type) {
 464                 case OBJ_BLOB:
 465                         ret = show_object(o->sha1, 0, NULL);
 466                         break;
 467                 case OBJ_TAG: {
 468                         struct tag *t = (struct tag *)o;
 469
 470                         if (rev.shown_one)
 471                                 putchar('\n');
 472                         printf("%stag %s%s\n",
 473                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 474                                         t->tag,
 475                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 476                         ret = show_object(o->sha1, 1, &rev);
 477                         rev.shown_one = 1;
 478                         if (ret)
 479                                 break;
 480                         o = parse_object(t->tagged->sha1);
 481                         if (!o)
 482                                 ret = error(_("Could not read object %s"),
 483                                             sha1_to_hex(t->tagged->sha1));
 484                         objects[i].item = o;
 485                         i--;
 486                         break;
 487                 }
 488                 case OBJ_TREE:
 489                         if (rev.shown_one)
 490                                 putchar('\n');
 491                         printf("%stree %s%s\n\n",
 492                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 493                                         name,
 494                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 495                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
 496                                         show_tree_object, NULL);
 497                         rev.shown_one = 1;
 498                         break;
 499                 case OBJ_COMMIT:
 500                         rev.pending.nr = rev.pending.alloc = 0;
 501                         rev.pending.objects = NULL;
 502                         add_object_array(o, name, &rev.pending);
 503                         ret = cmd_log_walk(&rev);
 504                         break;
 505                 default:
 506                         ret = error(_("Unknown type: %d"), o->type);
 507                 }
 508         }
 509         free(objects);
 510         return ret;
 511 }
 512
 513 /*
 514  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 515  */
 516 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 517 {
 518         struct rev_info rev;
 519         struct setup_revision_opt opt;
 520
 521         git_config(git_log_config, NULL);
 522
 523         init_revisions(&rev, prefix);
 524         init_reflog_walk(&rev.reflog_info);
 525         rev.verbose_header = 1;
 526         memset(&opt, 0, sizeof(opt));
 527         opt.def = "HEAD";
 528         cmd_log_init_defaults(&rev);
 529         rev.abbrev_commit = 1;
 530         rev.commit_format = CMIT_FMT_ONELINE;
 531         rev.use_terminator = 1;
 532         rev.always_show_header = 1;
 533         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
 534
 535         return cmd_log_walk(&rev);
 536 }
 537
 538 int cmd_log(int argc, const char **argv, const char *prefix)
 539 {
 540         struct rev_info rev;
 541         struct setup_revision_opt opt;
 542
 543         git_config(git_log_config, NULL);
 544
 545         init_revisions(&rev, prefix);
 546         rev.always_show_header = 1;
 547         memset(&opt, 0, sizeof(opt));
 548         opt.def = "HEAD";
 549         cmd_log_init(argc, argv, prefix, &rev, &opt);
 550         return cmd_log_walk(&rev);
 551 }
 552
 553 /* format-patch */
 554
 555 static const char *fmt_patch_suffix = ".patch";
 556 static int numbered = 0;
 557 static int auto_number = 1;
 558
 559 static char *default_attach = NULL;
 560
 561 static struct string_list extra_hdr;
 562 static struct string_list extra_to;
 563 static struct string_list extra_cc;
 564
 565 static void add_header(const char *value)
 566 {
 567         struct string_list_item *item;
 568         int len = strlen(value);
 569         while (len && value[len - 1] == '\n')
 570                 len--;
 571
 572         if (!strncasecmp(value, "to: ", 4)) {
 573                 item = string_list_append(&extra_to, value + 4);
 574                 len -= 4;
 575         } else if (!strncasecmp(value, "cc: ", 4)) {
 576                 item = string_list_append(&extra_cc, value + 4);
 577                 len -= 4;
 578         } else {
 579                 item = string_list_append(&extra_hdr, value);
 580         }
 581
 582         item->string[len] = '\0';
 583 }
 584
 585 #define THREAD_SHALLOW 1
 586 #define THREAD_DEEP 2
 587 static int thread;
 588 static int do_signoff;
 589 static const char *signature = git_version_string;
 590
 591 static int git_format_config(const char *var, const char *value, void *cb)
 592 {
 593         if (!strcmp(var, "format.headers")) {
 594                 if (!value)
 595                         die(_("format.headers without value"));
 596                 add_header(value);
 597                 return 0;
 598         }
 599         if (!strcmp(var, "format.suffix"))
 600                 return git_config_string(&fmt_patch_suffix, var, value);
 601         if (!strcmp(var, "format.to")) {
 602                 if (!value)
 603                         return config_error_nonbool(var);
 604                 string_list_append(&extra_to, value);
 605                 return 0;
 606         }
 607         if (!strcmp(var, "format.cc")) {
 608                 if (!value)
 609                         return config_error_nonbool(var);
 610                 string_list_append(&extra_cc, value);
 611                 return 0;
 612         }
 613         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
 614             !strcmp(var, "color.ui")) {
 615                 return 0;
 616         }
 617         if (!strcmp(var, "format.numbered")) {
 618                 if (value && !strcasecmp(value, "auto")) {
 619                         auto_number = 1;
 620                         return 0;
 621                 }
 622                 numbered = git_config_bool(var, value);
 623                 auto_number = auto_number && numbered;
 624                 return 0;
 625         }
 626         if (!strcmp(var, "format.attach")) {
 627                 if (value && *value)
 628                         default_attach = xstrdup(value);
 629                 else
 630                         default_attach = xstrdup(git_version_string);
 631                 return 0;
 632         }
 633         if (!strcmp(var, "format.thread")) {
 634                 if (value && !strcasecmp(value, "deep")) {
 635                         thread = THREAD_DEEP;
 636                         return 0;
 637                 }
 638                 if (value && !strcasecmp(value, "shallow")) {
 639                         thread = THREAD_SHALLOW;
 640                         return 0;
 641                 }
 642                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
 643                 return 0;
 644         }
 645         if (!strcmp(var, "format.signoff")) {
 646                 do_signoff = git_config_bool(var, value);
 647                 return 0;
 648         }
 649         if (!strcmp(var, "format.signature"))
 650                 return git_config_string(&signature, var, value);
 651
 652         return git_log_config(var, value, cb);
 653 }
 654
 655 static FILE *realstdout = NULL;
 656 static const char *output_directory = NULL;
 657 static int outdir_offset;
 658
 659 static int reopen_stdout(struct commit *commit, struct rev_info *rev, int quiet)
 660 {
 661         struct strbuf filename = STRBUF_INIT;
 662         int suffix_len = strlen(fmt_patch_suffix) + 1;
 663
 664         if (output_directory) {
 665                 strbuf_addstr(&filename, output_directory);
 666                 if (filename.len >=
 667                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
 668                         return error(_("name of output directory is too long"));
 669                 if (filename.buf[filename.len - 1] != '/')
 670                         strbuf_addch(&filename, '/');
 671         }
 672
 673         get_patch_filename(commit, rev->nr, fmt_patch_suffix, &filename);
 674
 675         if (!quiet)
 676                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
 677
 678         if (freopen(filename.buf, "w", stdout) == NULL)
 679                 return error(_("Cannot open patch file %s"), filename.buf);
 680
 681         strbuf_release(&filename);
 682         return 0;
 683 }
 684
 685 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
 686 {
 687         struct rev_info check_rev;
 688         struct commit *commit;
 689         struct object *o1, *o2;
 690         unsigned flags1, flags2;
 691
 692         if (rev->pending.nr != 2)
 693                 die(_("Need exactly one range."));
 694
 695         o1 = rev->pending.objects[0].item;
 696         flags1 = o1->flags;
 697         o2 = rev->pending.objects[1].item;
 698         flags2 = o2->flags;
 699
 700         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 701                 die(_("Not a range."));
 702
 703         init_patch_ids(ids);
 704
 705         /* given a range a..b get all patch ids for b..a */
 706         init_revisions(&check_rev, prefix);
 707         o1->flags ^= UNINTERESTING;
 708         o2->flags ^= UNINTERESTING;
 709         add_pending_object(&check_rev, o1, "o1");
 710         add_pending_object(&check_rev, o2, "o2");
 711         if (prepare_revision_walk(&check_rev))
 712                 die(_("revision walk setup failed"));
 713
 714         while ((commit = get_revision(&check_rev)) != NULL) {
 715                 /* ignore merges */
 716                 if (commit->parents && commit->parents->next)
 717                         continue;
 718
 719                 add_commit_patch_id(commit, ids);
 720         }
 721
 722         /* reset for next revision walk */
 723         clear_commit_marks((struct commit *)o1,
 724                         SEEN | UNINTERESTING | SHOWN | ADDED);
 725         clear_commit_marks((struct commit *)o2,
 726                         SEEN | UNINTERESTING | SHOWN | ADDED);
 727         o1->flags = flags1;
 728         o2->flags = flags2;
 729 }
 730
 731 static void gen_message_id(struct rev_info *info, char *base)
 732 {
 733         const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 734         const char *email_start = strrchr(committer, '<');
 735         const char *email_end = strrchr(committer, '>');
 736         struct strbuf buf = STRBUF_INIT;
 737         if (!email_start || !email_end || email_start > email_end - 1)
 738                 die(_("Could not extract email from committer identity."));
 739         strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
 740                     (unsigned long) time(NULL),
 741                     (int)(email_end - email_start - 1), email_start + 1);
 742         info->message_id = strbuf_detach(&buf, NULL);
 743 }
 744
 745 static void print_signature(void)
 746 {
 747         if (signature && *signature)
 748                 printf("-- \n%s\n\n", signature);
 749 }
 750
 751 static void add_branch_description(struct strbuf *buf, const char *branch_name)
 752 {
 753         struct strbuf desc = STRBUF_INIT;
 754         if (!branch_name || !*branch_name)
 755                 return;
 756         read_branch_desc(&desc, branch_name);
 757         if (desc.len) {
 758                 strbuf_addch(buf, '\n');
 759                 strbuf_add(buf, desc.buf, desc.len);
 760                 strbuf_addch(buf, '\n');
 761         }
 762 }
 763
 764 static void make_cover_letter(struct rev_info *rev, int use_stdout,
 765                               int numbered, int numbered_files,
 766                               struct commit *origin,
 767                               int nr, struct commit **list, struct commit *head,
 768                               const char *branch_name,
 769                               int quiet)
 770 {
 771         const char *committer;
 772         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
 773         const char *msg;
 774         struct shortlog log;
 775         struct strbuf sb = STRBUF_INIT;
 776         int i;
 777         const char *encoding = "UTF-8";
 778         struct diff_options opts;
 779         int need_8bit_cte = 0;
 780         struct commit *commit = NULL;
 781         struct pretty_print_context pp = {0};
 782
 783         if (rev->commit_format != CMIT_FMT_EMAIL)
 784                 die(_("Cover letter needs email format"));
 785
 786         committer = git_committer_info(0);
 787
 788         if (!numbered_files) {
 789                 /*
 790                  * We fake a commit for the cover letter so we get the filename
 791                  * desired.
 792                  */
 793                 commit = xcalloc(1, sizeof(*commit));
 794                 commit->buffer = xmalloc(400);
 795                 snprintf(commit->buffer, 400,
 796                         "tree 0000000000000000000000000000000000000000\n"
 797                         "parent %s\n"
 798                         "author %s\n"
 799                         "committer %s\n\n"
 800                         "cover letter\n",
 801                         sha1_to_hex(head->object.sha1), committer, committer);
 802         }
 803
 804         if (!use_stdout && reopen_stdout(commit, rev, quiet))
 805                 return;
 806
 807         if (commit) {
 808
 809                 free(commit->buffer);
 810                 free(commit);
 811         }
 812
 813         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
 814                                 &need_8bit_cte);
 815
 816         for (i = 0; !need_8bit_cte && i < nr; i++)
 817                 if (has_non_ascii(list[i]->buffer))
 818                         need_8bit_cte = 1;
 819
 820         msg = body;
 821         pp.fmt = CMIT_FMT_EMAIL;
 822         pp.date_mode = DATE_RFC2822;
 823         pp_user_info(&pp, NULL, &sb, committer, encoding);
 824         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 825         pp_remainder(&pp, &msg, &sb, 0);
 826         add_branch_description(&sb, branch_name);
 827         printf("%s\n", sb.buf);
 828
 829         strbuf_release(&sb);
 830
 831         shortlog_init(&log);
 832         log.wrap_lines = 1;
 833         log.wrap = 72;
 834         log.in1 = 2;
 835         log.in2 = 4;
 836         for (i = 0; i < nr; i++)
 837                 shortlog_add_commit(&log, list[i]);
 838
 839         shortlog_output(&log);
 840
 841         /*
 842          * We can only do diffstat with a unique reference point
 843          */
 844         if (!origin)
 845                 return;
 846
 847         memcpy(&opts, &rev->diffopt, sizeof(opts));
 848         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 849
 850         diff_setup_done(&opts);
 851
 852         diff_tree_sha1(origin->tree->object.sha1,
 853                        head->tree->object.sha1,
 854                        "", &opts);
 855         diffcore_std(&opts);
 856         diff_flush(&opts);
 857
 858         printf("\n");
 859         print_signature();
 860 }
 861
 862 static const char *clean_message_id(const char *msg_id)
 863 {
 864         char ch;
 865         const char *a, *z, *m;
 866
 867         m = msg_id;
 868         while ((ch = *m) && (isspace(ch) || (ch == '<')))
 869                 m++;
 870         a = m;
 871         z = NULL;
 872         while ((ch = *m)) {
 873                 if (!isspace(ch) && (ch != '>'))
 874                         z = m;
 875                 m++;
 876         }
 877         if (!z)
 878                 die(_("insane in-reply-to: %s"), msg_id);
 879         if (++z == m)
 880                 return a;
 881         return xmemdupz(a, z - a);
 882 }
 883
 884 static const char *set_outdir(const char *prefix, const char *output_directory)
 885 {
 886         if (output_directory && is_absolute_path(output_directory))
 887                 return output_directory;
 888
 889         if (!prefix || !*prefix) {
 890                 if (output_directory)
 891                         return output_directory;
 892                 /* The user did not explicitly ask for "./" */
 893                 outdir_offset = 2;
 894                 return "./";
 895         }
 896
 897         outdir_offset = strlen(prefix);
 898         if (!output_directory)
 899                 return prefix;
 900
 901         return xstrdup(prefix_filename(prefix, outdir_offset,
 902                                        output_directory));
 903 }
 904
 905 static const char * const builtin_format_patch_usage[] = {
 906         "git format-patch [options] [<since> | <revision range>]",
 907         NULL
 908 };
 909
 910 static int keep_subject = 0;
 911
 912 static int keep_callback(const struct option *opt, const char *arg, int unset)
 913 {
 914         ((struct rev_info *)opt->value)->total = -1;
 915         keep_subject = 1;
 916         return 0;
 917 }
 918
 919 static int subject_prefix = 0;
 920
 921 static int subject_prefix_callback(const struct option *opt, const char *arg,
 922                             int unset)
 923 {
 924         subject_prefix = 1;
 925         ((struct rev_info *)opt->value)->subject_prefix = arg;
 926         return 0;
 927 }
 928
 929 static int numbered_cmdline_opt = 0;
 930
 931 static int numbered_callback(const struct option *opt, const char *arg,
 932                              int unset)
 933 {
 934         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 935         if (unset)
 936                 auto_number =  0;
 937         return 0;
 938 }
 939
 940 static int no_numbered_callback(const struct option *opt, const char *arg,
 941                                 int unset)
 942 {
 943         return numbered_callback(opt, arg, 1);
 944 }
 945
 946 static int output_directory_callback(const struct option *opt, const char *arg,
 947                               int unset)
 948 {
 949         const char **dir = (const char **)opt->value;
 950         if (*dir)
 951                 die(_("Two output directories?"));
 952         *dir = arg;
 953         return 0;
 954 }
 955
 956 static int thread_callback(const struct option *opt, const char *arg, int unset)
 957 {
 958         int *thread = (int *)opt->value;
 959         if (unset)
 960                 *thread = 0;
 961         else if (!arg || !strcmp(arg, "shallow"))
 962                 *thread = THREAD_SHALLOW;
 963         else if (!strcmp(arg, "deep"))
 964                 *thread = THREAD_DEEP;
 965         else
 966                 return 1;
 967         return 0;
 968 }
 969
 970 static int attach_callback(const struct option *opt, const char *arg, int unset)
 971 {
 972         struct rev_info *rev = (struct rev_info *)opt->value;
 973         if (unset)
 974                 rev->mime_boundary = NULL;
 975         else if (arg)
 976                 rev->mime_boundary = arg;
 977         else
 978                 rev->mime_boundary = git_version_string;
 979         rev->no_inline = unset ? 0 : 1;
 980         return 0;
 981 }
 982
 983 static int inline_callback(const struct option *opt, const char *arg, int unset)
 984 {
 985         struct rev_info *rev = (struct rev_info *)opt->value;
 986         if (unset)
 987                 rev->mime_boundary = NULL;
 988         else if (arg)
 989                 rev->mime_boundary = arg;
 990         else
 991                 rev->mime_boundary = git_version_string;
 992         rev->no_inline = 0;
 993         return 0;
 994 }
 995
 996 static int header_callback(const struct option *opt, const char *arg, int unset)
 997 {
 998         if (unset) {
 999                 string_list_clear(&extra_hdr, 0);
1000                 string_list_clear(&extra_to, 0);
1001                 string_list_clear(&extra_cc, 0);
1002         } else {
1003             add_header(arg);
1004         }
1005         return 0;
1006 }
1007
1008 static int to_callback(const struct option *opt, const char *arg, int unset)
1009 {
1010         if (unset)
1011                 string_list_clear(&extra_to, 0);
1012         else
1013                 string_list_append(&extra_to, arg);
1014         return 0;
1015 }
1016
1017 static int cc_callback(const struct option *opt, const char *arg, int unset)
1018 {
1019         if (unset)
1020                 string_list_clear(&extra_cc, 0);
1021         else
1022                 string_list_append(&extra_cc, arg);
1023         return 0;
1024 }
1025
1026 static char *find_branch_name(struct rev_info *rev)
1027 {
1028         int i, positive = -1;
1029         unsigned char branch_sha1[20];
1030         struct strbuf buf = STRBUF_INIT;
1031         const char *branch;
1032
1033         for (i = 0; i < rev->cmdline.nr; i++) {
1034                 if (rev->cmdline.rev[i].flags & UNINTERESTING)
1035                         continue;
1036                 if (positive < 0)
1037                         positive = i;
1038                 else
1039                         return NULL;
1040         }
1041         if (positive < 0)
1042                 return NULL;
1043         strbuf_addf(&buf, "refs/heads/%s", rev->cmdline.rev[positive].name);
1044         branch = resolve_ref_unsafe(buf.buf, branch_sha1, 1, NULL);
1045         if (!branch ||
1046             prefixcmp(branch, "refs/heads/") ||
1047             hashcmp(rev->cmdline.rev[positive].item->sha1, branch_sha1))
1048                 branch = NULL;
1049         strbuf_release(&buf);
1050         if (branch)
1051                 return xstrdup(rev->cmdline.rev[positive].name);
1052         return NULL;
1053 }
1054
1055 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1056 {
1057         struct commit *commit;
1058         struct commit **list = NULL;
1059         struct rev_info rev;
1060         struct setup_revision_opt s_r_opt;
1061         int nr = 0, total, i;
1062         int use_stdout = 0;
1063         int start_number = -1;
1064         int numbered_files = 0;         /* _just_ numbers */
1065         int ignore_if_in_upstream = 0;
1066         int cover_letter = 0;
1067         int boundary_count = 0;
1068         int no_binary_diff = 0;
1069         struct commit *origin = NULL, *head = NULL;
1070         const char *in_reply_to = NULL;
1071         struct patch_ids ids;
1072         char *add_signoff = NULL;
1073         struct strbuf buf = STRBUF_INIT;
1074         int use_patch_format = 0;
1075         int quiet = 0;
1076         char *branch_name = NULL;
1077         const struct option builtin_format_patch_options[] = {
1078                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1079                             "use [PATCH n/m] even with a single patch",
1080                             PARSE_OPT_NOARG, numbered_callback },
1081                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1082                             "use [PATCH] even with multiple patches",
1083                             PARSE_OPT_NOARG, no_numbered_callback },
1084                 OPT_BOOLEAN('s', "signoff", &do_signoff, "add Signed-off-by:"),
1085                 OPT_BOOLEAN(0, "stdout", &use_stdout,
1086                             "print patches to standard out"),
1087                 OPT_BOOLEAN(0, "cover-letter", &cover_letter,
1088                             "generate a cover letter"),
1089                 OPT_BOOLEAN(0, "numbered-files", &numbered_files,
1090                             "use simple number sequence for output file names"),
1091                 OPT_STRING(0, "suffix", &fmt_patch_suffix, "sfx",
1092                             "use <sfx> instead of '.patch'"),
1093                 OPT_INTEGER(0, "start-number", &start_number,
1094                             "start numbering patches at <n> instead of 1"),
1095                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, "prefix",
1096                             "Use [<prefix>] instead of [PATCH]",
1097                             PARSE_OPT_NONEG, subject_prefix_callback },
1098                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1099                             "dir", "store resulting files in <dir>",
1100                             PARSE_OPT_NONEG, output_directory_callback },
1101                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1102                             "don't strip/add [PATCH]",
1103                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1104                 OPT_BOOLEAN(0, "no-binary", &no_binary_diff,
1105                             "don't output binary diffs"),
1106                 OPT_BOOLEAN(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1107                             "don't include a patch matching a commit upstream"),
1108                 { OPTION_BOOLEAN, 'p', "no-stat", &use_patch_format, NULL,
1109                   "show patch format instead of default (patch + stat)",
1110                   PARSE_OPT_NONEG | PARSE_OPT_NOARG },
1111                 OPT_GROUP("Messaging"),
1112                 { OPTION_CALLBACK, 0, "add-header", NULL, "header",
1113                             "add email header", 0, header_callback },
1114                 { OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
1115                             0, to_callback },
1116                 { OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
1117                             0, cc_callback },
1118                 OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
1119                             "make first mail a reply to <message-id>"),
1120                 { OPTION_CALLBACK, 0, "attach", &rev, "boundary",
1121                             "attach the patch", PARSE_OPT_OPTARG,
1122                             attach_callback },
1123                 { OPTION_CALLBACK, 0, "inline", &rev, "boundary",
1124                             "inline the patch",
1125                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1126                             inline_callback },
1127                 { OPTION_CALLBACK, 0, "thread", &thread, "style",
1128                             "enable message threading, styles: shallow, deep",
1129                             PARSE_OPT_OPTARG, thread_callback },
1130                 OPT_STRING(0, "signature", &signature, "signature",
1131                             "add a signature"),
1132                 OPT_BOOLEAN(0, "quiet", &quiet,
1133                             "don't print the patch filenames"),
1134                 OPT_END()
1135         };
1136
1137         extra_hdr.strdup_strings = 1;
1138         extra_to.strdup_strings = 1;
1139         extra_cc.strdup_strings = 1;
1140         git_config(git_format_config, NULL);
1141         init_revisions(&rev, prefix);
1142         rev.commit_format = CMIT_FMT_EMAIL;
1143         rev.verbose_header = 1;
1144         rev.diff = 1;
1145         rev.max_parents = 1;
1146         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1147         rev.subject_prefix = fmt_patch_subject_prefix;
1148         memset(&s_r_opt, 0, sizeof(s_r_opt));
1149         s_r_opt.def = "HEAD";
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 }