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 #include "streaming.h"
  24
  25 /* Set a default date-time format for git log ("log.date" config variable) */
  26 static const char *default_date_mode = NULL;
  27
  28 static int default_abbrev_commit;
  29 static int default_show_root = 1;
  30 static int decoration_style;
  31 static int decoration_given;
  32 static const char *fmt_patch_subject_prefix = "PATCH";
  33 static const char *fmt_pretty;
  34
  35 static const char * const builtin_log_usage[] = {
  36         "git log [<options>] [<since>..<until>] [[--] <path>...]\n"
  37         "   or: git show [options] <object>...",
  38         NULL
  39 };
  40
  41 static int parse_decoration_style(const char *var, const char *value)
  42 {
  43         switch (git_config_maybe_bool(var, value)) {
  44         case 1:
  45                 return DECORATE_SHORT_REFS;
  46         case 0:
  47                 return 0;
  48         default:
  49                 break;
  50         }
  51         if (!strcmp(value, "full"))
  52                 return DECORATE_FULL_REFS;
  53         else if (!strcmp(value, "short"))
  54                 return DECORATE_SHORT_REFS;
  55         return -1;
  56 }
  57
  58 static int decorate_callback(const struct option *opt, const char *arg, int unset)
  59 {
  60         if (unset)
  61                 decoration_style = 0;
  62         else if (arg)
  63                 decoration_style = parse_decoration_style("command line", arg);
  64         else
  65                 decoration_style = DECORATE_SHORT_REFS;
  66
  67         if (decoration_style < 0)
  68                 die("invalid --decorate option: %s", arg);
  69
  70         decoration_given = 1;
  71
  72         return 0;
  73 }
  74
  75 static void cmd_log_init_defaults(struct rev_info *rev)
  76 {
  77         if (fmt_pretty)
  78                 get_commit_format(fmt_pretty, rev);
  79         rev->verbose_header = 1;
  80         DIFF_OPT_SET(&rev->diffopt, RECURSIVE);
  81         rev->diffopt.stat_width = -1; /* use full terminal width */
  82         rev->diffopt.stat_graph_width = -1; /* respect statGraphWidth config */
  83         rev->abbrev_commit = default_abbrev_commit;
  84         rev->show_root_diff = default_show_root;
  85         rev->subject_prefix = fmt_patch_subject_prefix;
  86         DIFF_OPT_SET(&rev->diffopt, ALLOW_TEXTCONV);
  87
  88         if (default_date_mode)
  89                 rev->date_mode = parse_date_format(default_date_mode);
  90 }
  91
  92 static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
  93                          struct rev_info *rev, struct setup_revision_opt *opt)
  94 {
  95         struct userformat_want w;
  96         int quiet = 0, source = 0;
  97
  98         const struct option builtin_log_options[] = {
  99                 OPT_BOOLEAN(0, "quiet", &quiet, "suppress diff output"),
 100                 OPT_BOOLEAN(0, "source", &source, "show source"),
 101                 { OPTION_CALLBACK, 0, "decorate", NULL, NULL, "decorate options",
 102                   PARSE_OPT_OPTARG, decorate_callback},
 103                 OPT_END()
 104         };
 105
 106         argc = parse_options(argc, argv, prefix,
 107                              builtin_log_options, builtin_log_usage,
 108                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
 109                              PARSE_OPT_KEEP_DASHDASH);
 110
 111         argc = setup_revisions(argc, argv, rev, opt);
 112         if (quiet)
 113                 rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
 114
 115         /* Any arguments at this point are not recognized */
 116         if (argc > 1)
 117                 die("unrecognized argument: %s", argv[1]);
 118
 119         memset(&w, 0, sizeof(w));
 120         userformat_find_requirements(NULL, &w);
 121
 122         if (!rev->show_notes_given && (!rev->pretty_given || w.notes))
 123                 rev->show_notes = 1;
 124         if (rev->show_notes)
 125                 init_display_notes(&rev->notes_opt);
 126
 127         if (rev->diffopt.pickaxe || rev->diffopt.filter)
 128                 rev->always_show_header = 0;
 129         if (DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES)) {
 130                 rev->always_show_header = 0;
 131                 if (rev->diffopt.pathspec.nr != 1)
 132                         usage("git logs can only follow renames on one pathname at a time");
 133         }
 134
 135         if (source)
 136                 rev->show_source = 1;
 137
 138         if (rev->pretty_given && rev->commit_format == CMIT_FMT_RAW) {
 139                 /*
 140                  * "log --pretty=raw" is special; ignore UI oriented
 141                  * configuration variables such as decoration.
 142                  */
 143                 if (!decoration_given)
 144                         decoration_style = 0;
 145                 if (!rev->abbrev_commit_given)
 146                         rev->abbrev_commit = 0;
 147         }
 148
 149         if (decoration_style) {
 150                 rev->show_decorations = 1;
 151                 load_ref_decorations(decoration_style);
 152         }
 153         setup_pager();
 154 }
 155
 156 static void cmd_log_init(int argc, const char **argv, const char *prefix,
 157                          struct rev_info *rev, struct setup_revision_opt *opt)
 158 {
 159         cmd_log_init_defaults(rev);
 160         cmd_log_init_finish(argc, argv, prefix, rev, opt);
 161 }
 162
 163 /*
 164  * This gives a rough estimate for how many commits we
 165  * will print out in the list.
 166  */
 167 static int estimate_commit_count(struct rev_info *rev, struct commit_list *list)
 168 {
 169         int n = 0;
 170
 171         while (list) {
 172                 struct commit *commit = list->item;
 173                 unsigned int flags = commit->object.flags;
 174                 list = list->next;
 175                 if (!(flags & (TREESAME | UNINTERESTING)))
 176                         n++;
 177         }
 178         return n;
 179 }
 180
 181 static void show_early_header(struct rev_info *rev, const char *stage, int nr)
 182 {
 183         if (rev->shown_one) {
 184                 rev->shown_one = 0;
 185                 if (rev->commit_format != CMIT_FMT_ONELINE)
 186                         putchar(rev->diffopt.line_termination);
 187         }
 188         printf(_("Final output: %d %s\n"), nr, stage);
 189 }
 190
 191 static struct itimerval early_output_timer;
 192
 193 static void log_show_early(struct rev_info *revs, struct commit_list *list)
 194 {
 195         int i = revs->early_output;
 196         int show_header = 1;
 197
 198         sort_in_topological_order(&list, revs->lifo);
 199         while (list && i) {
 200                 struct commit *commit = list->item;
 201                 switch (simplify_commit(revs, commit)) {
 202                 case commit_show:
 203                         if (show_header) {
 204                                 int n = estimate_commit_count(revs, list);
 205                                 show_early_header(revs, "incomplete", n);
 206                                 show_header = 0;
 207                         }
 208                         log_tree_commit(revs, commit);
 209                         i--;
 210                         break;
 211                 case commit_ignore:
 212                         break;
 213                 case commit_error:
 214                         return;
 215                 }
 216                 list = list->next;
 217         }
 218
 219         /* Did we already get enough commits for the early output? */
 220         if (!i)
 221                 return;
 222
 223         /*
 224          * ..if no, then repeat it twice a second until we
 225          * do.
 226          *
 227          * NOTE! We don't use "it_interval", because if the
 228          * reader isn't listening, we want our output to be
 229          * throttled by the writing, and not have the timer
 230          * trigger every second even if we're blocked on a
 231          * reader!
 232          */
 233         early_output_timer.it_value.tv_sec = 0;
 234         early_output_timer.it_value.tv_usec = 500000;
 235         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 236 }
 237
 238 static void early_output(int signal)
 239 {
 240         show_early_output = log_show_early;
 241 }
 242
 243 static void setup_early_output(struct rev_info *rev)
 244 {
 245         struct sigaction sa;
 246
 247         /*
 248          * Set up the signal handler, minimally intrusively:
 249          * we only set a single volatile integer word (not
 250          * using sigatomic_t - trying to avoid unnecessary
 251          * system dependencies and headers), and using
 252          * SA_RESTART.
 253          */
 254         memset(&sa, 0, sizeof(sa));
 255         sa.sa_handler = early_output;
 256         sigemptyset(&sa.sa_mask);
 257         sa.sa_flags = SA_RESTART;
 258         sigaction(SIGALRM, &sa, NULL);
 259
 260         /*
 261          * If we can get the whole output in less than a
 262          * tenth of a second, don't even bother doing the
 263          * early-output thing..
 264          *
 265          * This is a one-time-only trigger.
 266          */
 267         early_output_timer.it_value.tv_sec = 0;
 268         early_output_timer.it_value.tv_usec = 100000;
 269         setitimer(ITIMER_REAL, &early_output_timer, NULL);
 270 }
 271
 272 static void finish_early_output(struct rev_info *rev)
 273 {
 274         int n = estimate_commit_count(rev, rev->commits);
 275         signal(SIGALRM, SIG_IGN);
 276         show_early_header(rev, "done", n);
 277 }
 278
 279 static int cmd_log_walk(struct rev_info *rev)
 280 {
 281         struct commit *commit;
 282         int saved_nrl = 0;
 283         int saved_dcctc = 0;
 284
 285         if (rev->early_output)
 286                 setup_early_output(rev);
 287
 288         if (prepare_revision_walk(rev))
 289                 die(_("revision walk setup failed"));
 290
 291         if (rev->early_output)
 292                 finish_early_output(rev);
 293
 294         /*
 295          * For --check and --exit-code, the exit code is based on CHECK_FAILED
 296          * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
 297          * retain that state information if replacing rev->diffopt in this loop
 298          */
 299         while ((commit = get_revision(rev)) != NULL) {
 300                 if (!log_tree_commit(rev, commit) &&
 301                     rev->max_count >= 0)
 302                         /*
 303                          * We decremented max_count in get_revision,
 304                          * but we didn't actually show the commit.
 305                          */
 306                         rev->max_count++;
 307                 if (!rev->reflog_info) {
 308                         /* we allow cycles in reflog ancestry */
 309                         free(commit->buffer);
 310                         commit->buffer = NULL;
 311                 }
 312                 free_commit_list(commit->parents);
 313                 commit->parents = NULL;
 314                 if (saved_nrl < rev->diffopt.needed_rename_limit)
 315                         saved_nrl = rev->diffopt.needed_rename_limit;
 316                 if (rev->diffopt.degraded_cc_to_c)
 317                         saved_dcctc = 1;
 318         }
 319         rev->diffopt.degraded_cc_to_c = saved_dcctc;
 320         rev->diffopt.needed_rename_limit = saved_nrl;
 321
 322         if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
 323             DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
 324                 return 02;
 325         }
 326         return diff_result_code(&rev->diffopt, 0);
 327 }
 328
 329 static int git_log_config(const char *var, const char *value, void *cb)
 330 {
 331         if (!strcmp(var, "format.pretty"))
 332                 return git_config_string(&fmt_pretty, var, value);
 333         if (!strcmp(var, "format.subjectprefix"))
 334                 return git_config_string(&fmt_patch_subject_prefix, var, value);
 335         if (!strcmp(var, "log.abbrevcommit")) {
 336                 default_abbrev_commit = git_config_bool(var, value);
 337                 return 0;
 338         }
 339         if (!strcmp(var, "log.date"))
 340                 return git_config_string(&default_date_mode, var, value);
 341         if (!strcmp(var, "log.decorate")) {
 342                 decoration_style = parse_decoration_style(var, value);
 343                 if (decoration_style < 0)
 344                         decoration_style = 0; /* maybe warn? */
 345                 return 0;
 346         }
 347         if (!strcmp(var, "log.showroot")) {
 348                 default_show_root = git_config_bool(var, value);
 349                 return 0;
 350         }
 351         if (!prefixcmp(var, "color.decorate."))
 352                 return parse_decorate_color_config(var, 15, value);
 353
 354         return git_diff_ui_config(var, value, cb);
 355 }
 356
 357 int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 358 {
 359         struct rev_info rev;
 360         struct setup_revision_opt opt;
 361
 362         git_config(git_log_config, NULL);
 363
 364         init_revisions(&rev, prefix);
 365         rev.diff = 1;
 366         rev.simplify_history = 0;
 367         memset(&opt, 0, sizeof(opt));
 368         opt.def = "HEAD";
 369         cmd_log_init(argc, argv, prefix, &rev, &opt);
 370         if (!rev.diffopt.output_format)
 371                 rev.diffopt.output_format = DIFF_FORMAT_RAW;
 372         return cmd_log_walk(&rev);
 373 }
 374
 375 static void show_tagger(char *buf, int len, struct rev_info *rev)
 376 {
 377         struct strbuf out = STRBUF_INIT;
 378         struct pretty_print_context pp = {0};
 379
 380         pp.fmt = rev->commit_format;
 381         pp.date_mode = rev->date_mode;
 382         pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
 383         printf("%s", out.buf);
 384         strbuf_release(&out);
 385 }
 386
 387 static int show_blob_object(const unsigned char *sha1, struct rev_info *rev)
 388 {
 389         fflush(stdout);
 390         return stream_blob_to_fd(1, sha1, NULL, 0);
 391 }
 392
 393 static int show_tag_object(const unsigned char *sha1, struct rev_info *rev)
 394 {
 395         unsigned long size;
 396         enum object_type type;
 397         char *buf = read_sha1_file(sha1, &type, &size);
 398         int offset = 0;
 399
 400         if (!buf)
 401                 return error(_("Could not read object %s"), sha1_to_hex(sha1));
 402
 403         assert(type == OBJ_TAG);
 404         while (offset < size && buf[offset] != '\n') {
 405                 int new_offset = offset + 1;
 406                 while (new_offset < size && buf[new_offset++] != '\n')
 407                         ; /* do nothing */
 408                 if (!prefixcmp(buf + offset, "tagger "))
 409                         show_tagger(buf + offset + 7,
 410                                     new_offset - offset - 7, rev);
 411                 offset = new_offset;
 412         }
 413
 414         if (offset < size)
 415                 fwrite(buf + offset, size - offset, 1, stdout);
 416         free(buf);
 417         return 0;
 418 }
 419
 420 static int show_tree_object(const unsigned char *sha1,
 421                 const char *base, int baselen,
 422                 const char *pathname, unsigned mode, int stage, void *context)
 423 {
 424         printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
 425         return 0;
 426 }
 427
 428 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 429 {
 430         if (rev->ignore_merges) {
 431                 /* There was no "-m" on the command line */
 432                 rev->ignore_merges = 0;
 433                 if (!rev->first_parent_only && !rev->combine_merges) {
 434                         /* No "--first-parent", "-c", nor "--cc" */
 435                         rev->combine_merges = 1;
 436                         rev->dense_combined_merges = 1;
 437                 }
 438         }
 439         if (!rev->diffopt.output_format)
 440                 rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 441 }
 442
 443 int cmd_show(int argc, const char **argv, const char *prefix)
 444 {
 445         struct rev_info rev;
 446         struct object_array_entry *objects;
 447         struct setup_revision_opt opt;
 448         struct pathspec match_all;
 449         int i, count, ret = 0;
 450
 451         git_config(git_log_config, NULL);
 452
 453         init_pathspec(&match_all, NULL);
 454         init_revisions(&rev, prefix);
 455         rev.diff = 1;
 456         rev.always_show_header = 1;
 457         rev.no_walk = 1;
 458         rev.diffopt.stat_width = -1;    /* Scale to real terminal size */
 459
 460         memset(&opt, 0, sizeof(opt));
 461         opt.def = "HEAD";
 462         opt.tweak = show_rev_tweak_rev;
 463         cmd_log_init(argc, argv, prefix, &rev, &opt);
 464
 465         count = rev.pending.nr;
 466         objects = rev.pending.objects;
 467         for (i = 0; i < count && !ret; i++) {
 468                 struct object *o = objects[i].item;
 469                 const char *name = objects[i].name;
 470                 switch (o->type) {
 471                 case OBJ_BLOB:
 472                         ret = show_blob_object(o->sha1, NULL);
 473                         break;
 474                 case OBJ_TAG: {
 475                         struct tag *t = (struct tag *)o;
 476
 477                         if (rev.shown_one)
 478                                 putchar('\n');
 479                         printf("%stag %s%s\n",
 480                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 481                                         t->tag,
 482                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 483                         ret = show_tag_object(o->sha1, &rev);
 484                         rev.shown_one = 1;
 485                         if (ret)
 486                                 break;
 487                         o = parse_object(t->tagged->sha1);
 488                         if (!o)
 489                                 ret = error(_("Could not read object %s"),
 490                                             sha1_to_hex(t->tagged->sha1));
 491                         objects[i].item = o;
 492                         i--;
 493                         break;
 494                 }
 495                 case OBJ_TREE:
 496                         if (rev.shown_one)
 497                                 putchar('\n');
 498                         printf("%stree %s%s\n\n",
 499                                         diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 500                                         name,
 501                                         diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 502                         read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
 503                                         show_tree_object, NULL);
 504                         rev.shown_one = 1;
 505                         break;
 506                 case OBJ_COMMIT:
 507                         rev.pending.nr = rev.pending.alloc = 0;
 508                         rev.pending.objects = NULL;
 509                         add_object_array(o, name, &rev.pending);
 510                         ret = cmd_log_walk(&rev);
 511                         break;
 512                 default:
 513                         ret = error(_("Unknown type: %d"), o->type);
 514                 }
 515         }
 516         free(objects);
 517         return ret;
 518 }
 519
 520 /*
 521  * This is equivalent to "git log -g --abbrev-commit --pretty=oneline"
 522  */
 523 int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 524 {
 525         struct rev_info rev;
 526         struct setup_revision_opt opt;
 527
 528         git_config(git_log_config, NULL);
 529
 530         init_revisions(&rev, prefix);
 531         init_reflog_walk(&rev.reflog_info);
 532         rev.verbose_header = 1;
 533         memset(&opt, 0, sizeof(opt));
 534         opt.def = "HEAD";
 535         cmd_log_init_defaults(&rev);
 536         rev.abbrev_commit = 1;
 537         rev.commit_format = CMIT_FMT_ONELINE;
 538         rev.use_terminator = 1;
 539         rev.always_show_header = 1;
 540         cmd_log_init_finish(argc, argv, prefix, &rev, &opt);
 541
 542         return cmd_log_walk(&rev);
 543 }
 544
 545 int cmd_log(int argc, const char **argv, const char *prefix)
 546 {
 547         struct rev_info rev;
 548         struct setup_revision_opt opt;
 549
 550         git_config(git_log_config, NULL);
 551
 552         init_revisions(&rev, prefix);
 553         rev.always_show_header = 1;
 554         memset(&opt, 0, sizeof(opt));
 555         opt.def = "HEAD";
 556         cmd_log_init(argc, argv, prefix, &rev, &opt);
 557         return cmd_log_walk(&rev);
 558 }
 559
 560 /* format-patch */
 561
 562 static const char *fmt_patch_suffix = ".patch";
 563 static int numbered = 0;
 564 static int auto_number = 1;
 565
 566 static char *default_attach = NULL;
 567
 568 static struct string_list extra_hdr;
 569 static struct string_list extra_to;
 570 static struct string_list extra_cc;
 571
 572 static void add_header(const char *value)
 573 {
 574         struct string_list_item *item;
 575         int len = strlen(value);
 576         while (len && value[len - 1] == '\n')
 577                 len--;
 578
 579         if (!strncasecmp(value, "to: ", 4)) {
 580                 item = string_list_append(&extra_to, value + 4);
 581                 len -= 4;
 582         } else if (!strncasecmp(value, "cc: ", 4)) {
 583                 item = string_list_append(&extra_cc, value + 4);
 584                 len -= 4;
 585         } else {
 586                 item = string_list_append(&extra_hdr, value);
 587         }
 588
 589         item->string[len] = '\0';
 590 }
 591
 592 #define THREAD_SHALLOW 1
 593 #define THREAD_DEEP 2
 594 static int thread;
 595 static int do_signoff;
 596 static const char *signature = git_version_string;
 597
 598 static int git_format_config(const char *var, const char *value, void *cb)
 599 {
 600         if (!strcmp(var, "format.headers")) {
 601                 if (!value)
 602                         die(_("format.headers without value"));
 603                 add_header(value);
 604                 return 0;
 605         }
 606         if (!strcmp(var, "format.suffix"))
 607                 return git_config_string(&fmt_patch_suffix, var, value);
 608         if (!strcmp(var, "format.to")) {
 609                 if (!value)
 610                         return config_error_nonbool(var);
 611                 string_list_append(&extra_to, value);
 612                 return 0;
 613         }
 614         if (!strcmp(var, "format.cc")) {
 615                 if (!value)
 616                         return config_error_nonbool(var);
 617                 string_list_append(&extra_cc, value);
 618                 return 0;
 619         }
 620         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff") ||
 621             !strcmp(var, "color.ui")) {
 622                 return 0;
 623         }
 624         if (!strcmp(var, "format.numbered")) {
 625                 if (value && !strcasecmp(value, "auto")) {
 626                         auto_number = 1;
 627                         return 0;
 628                 }
 629                 numbered = git_config_bool(var, value);
 630                 auto_number = auto_number && numbered;
 631                 return 0;
 632         }
 633         if (!strcmp(var, "format.attach")) {
 634                 if (value && *value)
 635                         default_attach = xstrdup(value);
 636                 else
 637                         default_attach = xstrdup(git_version_string);
 638                 return 0;
 639         }
 640         if (!strcmp(var, "format.thread")) {
 641                 if (value && !strcasecmp(value, "deep")) {
 642                         thread = THREAD_DEEP;
 643                         return 0;
 644                 }
 645                 if (value && !strcasecmp(value, "shallow")) {
 646                         thread = THREAD_SHALLOW;
 647                         return 0;
 648                 }
 649                 thread = git_config_bool(var, value) && THREAD_SHALLOW;
 650                 return 0;
 651         }
 652         if (!strcmp(var, "format.signoff")) {
 653                 do_signoff = git_config_bool(var, value);
 654                 return 0;
 655         }
 656         if (!strcmp(var, "format.signature"))
 657                 return git_config_string(&signature, var, value);
 658
 659         return git_log_config(var, value, cb);
 660 }
 661
 662 static FILE *realstdout = NULL;
 663 static const char *output_directory = NULL;
 664 static int outdir_offset;
 665
 666 static int reopen_stdout(struct commit *commit, struct rev_info *rev, int quiet)
 667 {
 668         struct strbuf filename = STRBUF_INIT;
 669         int suffix_len = strlen(fmt_patch_suffix) + 1;
 670
 671         if (output_directory) {
 672                 strbuf_addstr(&filename, output_directory);
 673                 if (filename.len >=
 674                     PATH_MAX - FORMAT_PATCH_NAME_MAX - suffix_len)
 675                         return error(_("name of output directory is too long"));
 676                 if (filename.buf[filename.len - 1] != '/')
 677                         strbuf_addch(&filename, '/');
 678         }
 679
 680         get_patch_filename(commit, rev->nr, fmt_patch_suffix, &filename);
 681
 682         if (!quiet)
 683                 fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
 684
 685         if (freopen(filename.buf, "w", stdout) == NULL)
 686                 return error(_("Cannot open patch file %s"), filename.buf);
 687
 688         strbuf_release(&filename);
 689         return 0;
 690 }
 691
 692 static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const char *prefix)
 693 {
 694         struct rev_info check_rev;
 695         struct commit *commit;
 696         struct object *o1, *o2;
 697         unsigned flags1, flags2;
 698
 699         if (rev->pending.nr != 2)
 700                 die(_("Need exactly one range."));
 701
 702         o1 = rev->pending.objects[0].item;
 703         flags1 = o1->flags;
 704         o2 = rev->pending.objects[1].item;
 705         flags2 = o2->flags;
 706
 707         if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
 708                 die(_("Not a range."));
 709
 710         init_patch_ids(ids);
 711
 712         /* given a range a..b get all patch ids for b..a */
 713         init_revisions(&check_rev, prefix);
 714         o1->flags ^= UNINTERESTING;
 715         o2->flags ^= UNINTERESTING;
 716         add_pending_object(&check_rev, o1, "o1");
 717         add_pending_object(&check_rev, o2, "o2");
 718         if (prepare_revision_walk(&check_rev))
 719                 die(_("revision walk setup failed"));
 720
 721         while ((commit = get_revision(&check_rev)) != NULL) {
 722                 /* ignore merges */
 723                 if (commit->parents && commit->parents->next)
 724                         continue;
 725
 726                 add_commit_patch_id(commit, ids);
 727         }
 728
 729         /* reset for next revision walk */
 730         clear_commit_marks((struct commit *)o1,
 731                         SEEN | UNINTERESTING | SHOWN | ADDED);
 732         clear_commit_marks((struct commit *)o2,
 733                         SEEN | UNINTERESTING | SHOWN | ADDED);
 734         o1->flags = flags1;
 735         o2->flags = flags2;
 736 }
 737
 738 static void gen_message_id(struct rev_info *info, char *base)
 739 {
 740         const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 741         const char *email_start = strrchr(committer, '<');
 742         const char *email_end = strrchr(committer, '>');
 743         struct strbuf buf = STRBUF_INIT;
 744         if (!email_start || !email_end || email_start > email_end - 1)
 745                 die(_("Could not extract email from committer identity."));
 746         strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
 747                     (unsigned long) time(NULL),
 748                     (int)(email_end - email_start - 1), email_start + 1);
 749         info->message_id = strbuf_detach(&buf, NULL);
 750 }
 751
 752 static void print_signature(void)
 753 {
 754         if (signature && *signature)
 755                 printf("-- \n%s\n\n", signature);
 756 }
 757
 758 static void add_branch_description(struct strbuf *buf, const char *branch_name)
 759 {
 760         struct strbuf desc = STRBUF_INIT;
 761         if (!branch_name || !*branch_name)
 762                 return;
 763         read_branch_desc(&desc, branch_name);
 764         if (desc.len) {
 765                 strbuf_addch(buf, '\n');
 766                 strbuf_add(buf, desc.buf, desc.len);
 767                 strbuf_addch(buf, '\n');
 768         }
 769 }
 770
 771 static void make_cover_letter(struct rev_info *rev, int use_stdout,
 772                               int numbered, int numbered_files,
 773                               struct commit *origin,
 774                               int nr, struct commit **list, struct commit *head,
 775                               const char *branch_name,
 776                               int quiet)
 777 {
 778         const char *committer;
 779         const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
 780         const char *msg;
 781         struct shortlog log;
 782         struct strbuf sb = STRBUF_INIT;
 783         int i;
 784         const char *encoding = "UTF-8";
 785         struct diff_options opts;
 786         int need_8bit_cte = 0;
 787         struct commit *commit = NULL;
 788         struct pretty_print_context pp = {0};
 789
 790         if (rev->commit_format != CMIT_FMT_EMAIL)
 791                 die(_("Cover letter needs email format"));
 792
 793         committer = git_committer_info(0);
 794
 795         if (!numbered_files) {
 796                 /*
 797                  * We fake a commit for the cover letter so we get the filename
 798                  * desired.
 799                  */
 800                 commit = xcalloc(1, sizeof(*commit));
 801                 commit->buffer = xmalloc(400);
 802                 snprintf(commit->buffer, 400,
 803                         "tree 0000000000000000000000000000000000000000\n"
 804                         "parent %s\n"
 805                         "author %s\n"
 806                         "committer %s\n\n"
 807                         "cover letter\n",
 808                         sha1_to_hex(head->object.sha1), committer, committer);
 809         }
 810
 811         if (!use_stdout && reopen_stdout(commit, rev, quiet))
 812                 return;
 813
 814         if (commit) {
 815
 816                 free(commit->buffer);
 817                 free(commit);
 818         }
 819
 820         log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
 821                                 &need_8bit_cte);
 822
 823         for (i = 0; !need_8bit_cte && i < nr; i++)
 824                 if (has_non_ascii(list[i]->buffer))
 825                         need_8bit_cte = 1;
 826
 827         msg = body;
 828         pp.fmt = CMIT_FMT_EMAIL;
 829         pp.date_mode = DATE_RFC2822;
 830         pp_user_info(&pp, NULL, &sb, committer, encoding);
 831         pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 832         pp_remainder(&pp, &msg, &sb, 0);
 833         add_branch_description(&sb, branch_name);
 834         printf("%s\n", sb.buf);
 835
 836         strbuf_release(&sb);
 837
 838         shortlog_init(&log);
 839         log.wrap_lines = 1;
 840         log.wrap = 72;
 841         log.in1 = 2;
 842         log.in2 = 4;
 843         for (i = 0; i < nr; i++)
 844                 shortlog_add_commit(&log, list[i]);
 845
 846         shortlog_output(&log);
 847
 848         /*
 849          * We can only do diffstat with a unique reference point
 850          */
 851         if (!origin)
 852                 return;
 853
 854         memcpy(&opts, &rev->diffopt, sizeof(opts));
 855         opts.output_format = DIFF_FORMAT_SUMMARY | DIFF_FORMAT_DIFFSTAT;
 856
 857         diff_setup_done(&opts);
 858
 859         diff_tree_sha1(origin->tree->object.sha1,
 860                        head->tree->object.sha1,
 861                        "", &opts);
 862         diffcore_std(&opts);
 863         diff_flush(&opts);
 864
 865         printf("\n");
 866         print_signature();
 867 }
 868
 869 static const char *clean_message_id(const char *msg_id)
 870 {
 871         char ch;
 872         const char *a, *z, *m;
 873
 874         m = msg_id;
 875         while ((ch = *m) && (isspace(ch) || (ch == '<')))
 876                 m++;
 877         a = m;
 878         z = NULL;
 879         while ((ch = *m)) {
 880                 if (!isspace(ch) && (ch != '>'))
 881                         z = m;
 882                 m++;
 883         }
 884         if (!z)
 885                 die(_("insane in-reply-to: %s"), msg_id);
 886         if (++z == m)
 887                 return a;
 888         return xmemdupz(a, z - a);
 889 }
 890
 891 static const char *set_outdir(const char *prefix, const char *output_directory)
 892 {
 893         if (output_directory && is_absolute_path(output_directory))
 894                 return output_directory;
 895
 896         if (!prefix || !*prefix) {
 897                 if (output_directory)
 898                         return output_directory;
 899                 /* The user did not explicitly ask for "./" */
 900                 outdir_offset = 2;
 901                 return "./";
 902         }
 903
 904         outdir_offset = strlen(prefix);
 905         if (!output_directory)
 906                 return prefix;
 907
 908         return xstrdup(prefix_filename(prefix, outdir_offset,
 909                                        output_directory));
 910 }
 911
 912 static const char * const builtin_format_patch_usage[] = {
 913         "git format-patch [options] [<since> | <revision range>]",
 914         NULL
 915 };
 916
 917 static int keep_subject = 0;
 918
 919 static int keep_callback(const struct option *opt, const char *arg, int unset)
 920 {
 921         ((struct rev_info *)opt->value)->total = -1;
 922         keep_subject = 1;
 923         return 0;
 924 }
 925
 926 static int subject_prefix = 0;
 927
 928 static int subject_prefix_callback(const struct option *opt, const char *arg,
 929                             int unset)
 930 {
 931         subject_prefix = 1;
 932         ((struct rev_info *)opt->value)->subject_prefix = arg;
 933         return 0;
 934 }
 935
 936 static int numbered_cmdline_opt = 0;
 937
 938 static int numbered_callback(const struct option *opt, const char *arg,
 939                              int unset)
 940 {
 941         *(int *)opt->value = numbered_cmdline_opt = unset ? 0 : 1;
 942         if (unset)
 943                 auto_number =  0;
 944         return 0;
 945 }
 946
 947 static int no_numbered_callback(const struct option *opt, const char *arg,
 948                                 int unset)
 949 {
 950         return numbered_callback(opt, arg, 1);
 951 }
 952
 953 static int output_directory_callback(const struct option *opt, const char *arg,
 954                               int unset)
 955 {
 956         const char **dir = (const char **)opt->value;
 957         if (*dir)
 958                 die(_("Two output directories?"));
 959         *dir = arg;
 960         return 0;
 961 }
 962
 963 static int thread_callback(const struct option *opt, const char *arg, int unset)
 964 {
 965         int *thread = (int *)opt->value;
 966         if (unset)
 967                 *thread = 0;
 968         else if (!arg || !strcmp(arg, "shallow"))
 969                 *thread = THREAD_SHALLOW;
 970         else if (!strcmp(arg, "deep"))
 971                 *thread = THREAD_DEEP;
 972         else
 973                 return 1;
 974         return 0;
 975 }
 976
 977 static int attach_callback(const struct option *opt, const char *arg, int unset)
 978 {
 979         struct rev_info *rev = (struct rev_info *)opt->value;
 980         if (unset)
 981                 rev->mime_boundary = NULL;
 982         else if (arg)
 983                 rev->mime_boundary = arg;
 984         else
 985                 rev->mime_boundary = git_version_string;
 986         rev->no_inline = unset ? 0 : 1;
 987         return 0;
 988 }
 989
 990 static int inline_callback(const struct option *opt, const char *arg, int unset)
 991 {
 992         struct rev_info *rev = (struct rev_info *)opt->value;
 993         if (unset)
 994                 rev->mime_boundary = NULL;
 995         else if (arg)
 996                 rev->mime_boundary = arg;
 997         else
 998                 rev->mime_boundary = git_version_string;
 999         rev->no_inline = 0;
1000         return 0;
1001 }
1002
1003 static int header_callback(const struct option *opt, const char *arg, int unset)
1004 {
1005         if (unset) {
1006                 string_list_clear(&extra_hdr, 0);
1007                 string_list_clear(&extra_to, 0);
1008                 string_list_clear(&extra_cc, 0);
1009         } else {
1010             add_header(arg);
1011         }
1012         return 0;
1013 }
1014
1015 static int to_callback(const struct option *opt, const char *arg, int unset)
1016 {
1017         if (unset)
1018                 string_list_clear(&extra_to, 0);
1019         else
1020                 string_list_append(&extra_to, arg);
1021         return 0;
1022 }
1023
1024 static int cc_callback(const struct option *opt, const char *arg, int unset)
1025 {
1026         if (unset)
1027                 string_list_clear(&extra_cc, 0);
1028         else
1029                 string_list_append(&extra_cc, arg);
1030         return 0;
1031 }
1032
1033 static char *find_branch_name(struct rev_info *rev)
1034 {
1035         int i, positive = -1;
1036         unsigned char branch_sha1[20];
1037         struct strbuf buf = STRBUF_INIT;
1038         const char *branch;
1039
1040         for (i = 0; i < rev->cmdline.nr; i++) {
1041                 if (rev->cmdline.rev[i].flags & UNINTERESTING)
1042                         continue;
1043                 if (positive < 0)
1044                         positive = i;
1045                 else
1046                         return NULL;
1047         }
1048         if (positive < 0)
1049                 return NULL;
1050         strbuf_addf(&buf, "refs/heads/%s", rev->cmdline.rev[positive].name);
1051         branch = resolve_ref_unsafe(buf.buf, branch_sha1, 1, NULL);
1052         if (!branch ||
1053             prefixcmp(branch, "refs/heads/") ||
1054             hashcmp(rev->cmdline.rev[positive].item->sha1, branch_sha1))
1055                 branch = NULL;
1056         strbuf_release(&buf);
1057         if (branch)
1058                 return xstrdup(rev->cmdline.rev[positive].name);
1059         return NULL;
1060 }
1061
1062 int cmd_format_patch(int argc, const char **argv, const char *prefix)
1063 {
1064         struct commit *commit;
1065         struct commit **list = NULL;
1066         struct rev_info rev;
1067         struct setup_revision_opt s_r_opt;
1068         int nr = 0, total, i;
1069         int use_stdout = 0;
1070         int start_number = -1;
1071         int numbered_files = 0;         /* _just_ numbers */
1072         int ignore_if_in_upstream = 0;
1073         int cover_letter = 0;
1074         int boundary_count = 0;
1075         int no_binary_diff = 0;
1076         struct commit *origin = NULL, *head = NULL;
1077         const char *in_reply_to = NULL;
1078         struct patch_ids ids;
1079         char *add_signoff = NULL;
1080         struct strbuf buf = STRBUF_INIT;
1081         int use_patch_format = 0;
1082         int quiet = 0;
1083         char *branch_name = NULL;
1084         const struct option builtin_format_patch_options[] = {
1085                 { OPTION_CALLBACK, 'n', "numbered", &numbered, NULL,
1086                             "use [PATCH n/m] even with a single patch",
1087                             PARSE_OPT_NOARG, numbered_callback },
1088                 { OPTION_CALLBACK, 'N', "no-numbered", &numbered, NULL,
1089                             "use [PATCH] even with multiple patches",
1090                             PARSE_OPT_NOARG, no_numbered_callback },
1091                 OPT_BOOLEAN('s', "signoff", &do_signoff, "add Signed-off-by:"),
1092                 OPT_BOOLEAN(0, "stdout", &use_stdout,
1093                             "print patches to standard out"),
1094                 OPT_BOOLEAN(0, "cover-letter", &cover_letter,
1095                             "generate a cover letter"),
1096                 OPT_BOOLEAN(0, "numbered-files", &numbered_files,
1097                             "use simple number sequence for output file names"),
1098                 OPT_STRING(0, "suffix", &fmt_patch_suffix, "sfx",
1099                             "use <sfx> instead of '.patch'"),
1100                 OPT_INTEGER(0, "start-number", &start_number,
1101                             "start numbering patches at <n> instead of 1"),
1102                 { OPTION_CALLBACK, 0, "subject-prefix", &rev, "prefix",
1103                             "Use [<prefix>] instead of [PATCH]",
1104                             PARSE_OPT_NONEG, subject_prefix_callback },
1105                 { OPTION_CALLBACK, 'o', "output-directory", &output_directory,
1106                             "dir", "store resulting files in <dir>",
1107                             PARSE_OPT_NONEG, output_directory_callback },
1108                 { OPTION_CALLBACK, 'k', "keep-subject", &rev, NULL,
1109                             "don't strip/add [PATCH]",
1110                             PARSE_OPT_NOARG | PARSE_OPT_NONEG, keep_callback },
1111                 OPT_BOOLEAN(0, "no-binary", &no_binary_diff,
1112                             "don't output binary diffs"),
1113                 OPT_BOOLEAN(0, "ignore-if-in-upstream", &ignore_if_in_upstream,
1114                             "don't include a patch matching a commit upstream"),
1115                 { OPTION_BOOLEAN, 'p', "no-stat", &use_patch_format, NULL,
1116                   "show patch format instead of default (patch + stat)",
1117                   PARSE_OPT_NONEG | PARSE_OPT_NOARG },
1118                 OPT_GROUP("Messaging"),
1119                 { OPTION_CALLBACK, 0, "add-header", NULL, "header",
1120                             "add email header", 0, header_callback },
1121                 { OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
1122                             0, to_callback },
1123                 { OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
1124                             0, cc_callback },
1125                 OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
1126                             "make first mail a reply to <message-id>"),
1127                 { OPTION_CALLBACK, 0, "attach", &rev, "boundary",
1128                             "attach the patch", PARSE_OPT_OPTARG,
1129                             attach_callback },
1130                 { OPTION_CALLBACK, 0, "inline", &rev, "boundary",
1131                             "inline the patch",
1132                             PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
1133                             inline_callback },
1134                 { OPTION_CALLBACK, 0, "thread", &thread, "style",
1135                             "enable message threading, styles: shallow, deep",
1136                             PARSE_OPT_OPTARG, thread_callback },
1137                 OPT_STRING(0, "signature", &signature, "signature",
1138                             "add a signature"),
1139                 OPT_BOOLEAN(0, "quiet", &quiet,
1140                             "don't print the patch filenames"),
1141                 OPT_END()
1142         };
1143
1144         extra_hdr.strdup_strings = 1;
1145         extra_to.strdup_strings = 1;
1146         extra_cc.strdup_strings = 1;
1147         git_config(git_format_config, NULL);
1148         init_revisions(&rev, prefix);
1149         rev.commit_format = CMIT_FMT_EMAIL;
1150         rev.verbose_header = 1;
1151         rev.diff = 1;
1152         rev.max_parents = 1;
1153         DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
1154         rev.subject_prefix = fmt_patch_subject_prefix;
1155         memset(&s_r_opt, 0, sizeof(s_r_opt));
1156         s_r_opt.def = "HEAD";
1157
1158         if (default_attach) {
1159                 rev.mime_boundary = default_attach;
1160                 rev.no_inline = 1;
1161         }
1162
1163         /*
1164          * Parse the arguments before setup_revisions(), or something
1165          * like "git format-patch -o a123 HEAD^.." may fail; a123 is
1166          * possibly a valid SHA1.
1167          */
1168         argc = parse_options(argc, argv, prefix, builtin_format_patch_options,
1169                              builtin_format_patch_usage,
1170                              PARSE_OPT_KEEP_ARGV0 | PARSE_OPT_KEEP_UNKNOWN |
1171                              PARSE_OPT_KEEP_DASHDASH);
1172
1173         if (do_signoff) {
1174                 const char *committer;
1175                 const char *endpos;
1176                 committer = git_committer_info(IDENT_ERROR_ON_NO_NAME);
1177                 endpos = strchr(committer, '>');
1178                 if (!endpos)
1179                         die(_("bogus committer info %s"), committer);
1180                 add_signoff = xmemdupz(committer, endpos - committer + 1);
1181         }
1182
1183         for (i = 0; i < extra_hdr.nr; i++) {
1184                 strbuf_addstr(&buf, extra_hdr.items[i].string);
1185                 strbuf_addch(&buf, '\n');
1186         }
1187
1188         if (extra_to.nr)
1189                 strbuf_addstr(&buf, "To: ");
1190         for (i = 0; i < extra_to.nr; i++) {
1191                 if (i)
1192                         strbuf_addstr(&buf, "    ");
1193                 strbuf_addstr(&buf, extra_to.items[i].string);
1194                 if (i + 1 < extra_to.nr)
1195                         strbuf_addch(&buf, ',');
1196                 strbuf_addch(&buf, '\n');
1197         }
1198
1199         if (extra_cc.nr)
1200                 strbuf_addstr(&buf, "Cc: ");
1201         for (i = 0; i < extra_cc.nr; i++) {
1202                 if (i)
1203                         strbuf_addstr(&buf, "    ");
1204                 strbuf_addstr(&buf, extra_cc.items[i].string);
1205                 if (i + 1 < extra_cc.nr)
1206                         strbuf_addch(&buf, ',');
1207                 strbuf_addch(&buf, '\n');
1208         }
1209
1210         rev.extra_headers = strbuf_detach(&buf, NULL);
1211
1212         if (start_number < 0)
1213                 start_number = 1;
1214
1215         /*
1216          * If numbered is set solely due to format.numbered in config,
1217          * and it would conflict with --keep-subject (-k) from the
1218          * command line, reset "numbered".
1219          */
1220         if (numbered && keep_subject && !numbered_cmdline_opt)
1221                 numbered = 0;
1222
1223         if (numbered && keep_subject)
1224                 die (_("-n and -k are mutually exclusive."));
1225         if (keep_subject && subject_prefix)
1226                 die (_("--subject-prefix and -k are mutually exclusive."));
1227         rev.preserve_subject = keep_subject;
1228
1229         argc = setup_revisions(argc, argv, &rev, &s_r_opt);
1230         if (argc > 1)
1231                 die (_("unrecognized argument: %s"), argv[1]);
1232
1233         if (rev.diffopt.output_format & DIFF_FORMAT_NAME)
1234                 die(_("--name-only does not make sense"));
1235         if (rev.diffopt.output_format & DIFF_FORMAT_NAME_STATUS)
1236                 die(_("--name-status does not make sense"));
1237         if (rev.diffopt.output_format & DIFF_FORMAT_CHECKDIFF)
1238                 die(_("--check does not make sense"));
1239
1240         if (!use_patch_format &&
1241                 (!rev.diffopt.output_format ||
1242                  rev.diffopt.output_format == DIFF_FORMAT_PATCH))
1243                 rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_SUMMARY;
1244
1245         /* Always generate a patch */
1246         rev.diffopt.output_format |= DIFF_FORMAT_PATCH;
1247
1248         if (!DIFF_OPT_TST(&rev.diffopt, TEXT) && !no_binary_diff)
1249                 DIFF_OPT_SET(&rev.diffopt, BINARY);
1250
1251         if (rev.show_notes)
1252                 init_display_notes(&rev.notes_opt);
1253
1254         if (!use_stdout)
1255                 output_directory = set_outdir(prefix, output_directory);
1256         else
1257                 setup_pager();
1258
1259         if (output_directory) {
1260                 if (use_stdout)
1261                         die(_("standard output, or directory, which one?"));
1262                 if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
1263                         die_errno(_("Could not create directory '%s'"),
1264                                   output_directory);
1265         }
1266
1267         if (rev.pending.nr == 1) {
1268                 if (rev.max_count < 0 && !rev.show_root_diff) {
1269                         /*
1270                          * This is traditional behaviour of "git format-patch
1271                          * origin" that prepares what the origin side still
1272                          * does not have.
1273                          */
1274                         unsigned char sha1[20];
1275                         const char *ref;
1276
1277                         rev.pending.objects[0].item->flags |= UNINTERESTING;
1278                         add_head_to_pending(&rev);
1279                         ref = resolve_ref_unsafe("HEAD", sha1, 1, NULL);
1280                         if (ref && !prefixcmp(ref, "refs/heads/"))
1281                                 branch_name = xstrdup(ref + strlen("refs/heads/"));
1282                         else
1283                                 branch_name = xstrdup(""); /* no branch */
1284                 }
1285                 /*
1286                  * Otherwise, it is "format-patch -22 HEAD", and/or
1287                  * "format-patch --root HEAD".  The user wants
1288                  * get_revision() to do the usual traversal.
1289                  */
1290         }
1291
1292         /*
1293          * We cannot move this anywhere earlier because we do want to
1294          * know if --root was given explicitly from the command line.
1295          */
1296         rev.show_root_diff = 1;
1297
1298         if (cover_letter) {
1299                 /*
1300                  * NEEDSWORK:randomly pick one positive commit to show
1301                  * diffstat; this is often the tip and the command
1302                  * happens to do the right thing in most cases, but a
1303                  * complex command like "--cover-letter a b c ^bottom"
1304                  * picks "c" and shows diffstat between bottom..c
1305                  * which may not match what the series represents at
1306                  * all and totally broken.
1307                  */
1308                 int i;
1309                 for (i = 0; i < rev.pending.nr; i++) {
1310                         struct object *o = rev.pending.objects[i].item;
1311                         if (!(o->flags & UNINTERESTING))
1312                                 head = (struct commit *)o;
1313                 }
1314                 /* There is nothing to show; it is not an error, though. */
1315                 if (!head)
1316                         return 0;
1317                 if (!branch_name)
1318                         branch_name = find_branch_name(&rev);
1319         }
1320
1321         if (ignore_if_in_upstream) {
1322                 /* Don't say anything if head and upstream are the same. */
1323                 if (rev.pending.nr == 2) {
1324                         struct object_array_entry *o = rev.pending.objects;
1325                         if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1326                                 return 0;
1327                 }
1328                 get_patch_ids(&rev, &ids, prefix);
1329         }
1330
1331         if (!use_stdout)
1332                 realstdout = xfdopen(xdup(1), "w");
1333
1334         if (prepare_revision_walk(&rev))
1335                 die(_("revision walk setup failed"));
1336         rev.boundary = 1;
1337         while ((commit = get_revision(&rev)) != NULL) {
1338                 if (commit->object.flags & BOUNDARY) {
1339                         boundary_count++;
1340                         origin = (boundary_count == 1) ? commit : NULL;
1341                         continue;
1342                 }
1343
1344                 if (ignore_if_in_upstream &&
1345                                 has_commit_patch_id(commit, &ids))
1346                         continue;
1347
1348                 nr++;
1349                 list = xrealloc(list, nr * sizeof(list[0]));
1350                 list[nr - 1] = commit;
1351         }
1352         total = nr;
1353         if (!keep_subject && auto_number && total > 1)
1354                 numbered = 1;
1355         if (numbered)
1356                 rev.total = total + start_number - 1;
1357         if (in_reply_to || thread || cover_letter)
1358                 rev.ref_message_ids = xcalloc(1, sizeof(struct string_list));
1359         if (in_reply_to) {
1360                 const char *msgid = clean_message_id(in_reply_to);
1361                 string_list_append(rev.ref_message_ids, msgid);
1362         }
1363         rev.numbered_files = numbered_files;
1364         rev.patch_suffix = fmt_patch_suffix;
1365         if (cover_letter) {
1366                 if (thread)
1367                         gen_message_id(&rev, "cover");
1368                 make_cover_letter(&rev, use_stdout, numbered, numbered_files,
1369                                   origin, nr, list, head, branch_name, quiet);
1370                 total++;
1371                 start_number--;
1372         }
1373         rev.add_signoff = add_signoff;
1374         while (0 <= --nr) {
1375                 int shown;
1376                 commit = list[nr];
1377                 rev.nr = total - nr + (start_number - 1);
1378                 /* Make the second and subsequent mails replies to the first */
1379                 if (thread) {
1380                         /* Have we already had a message ID? */
1381                         if (rev.message_id) {
1382                                 /*
1383                                  * For deep threading: make every mail
1384                                  * a reply to the previous one, no
1385                                  * matter what other options are set.
1386                                  *
1387                                  * For shallow threading:
1388                                  *
1389                                  * Without --cover-letter and
1390                                  * --in-reply-to, make every mail a
1391                                  * reply to the one before.
1392                                  *
1393                                  * With --in-reply-to but no
1394                                  * --cover-letter, make every mail a
1395                                  * reply to the <reply-to>.
1396                                  *
1397                                  * With --cover-letter, make every
1398                                  * mail but the cover letter a reply
1399                                  * to the cover letter.  The cover
1400                                  * letter is a reply to the
1401                                  * --in-reply-to, if specified.
1402                                  */
1403                                 if (thread == THREAD_SHALLOW
1404                                     && rev.ref_message_ids->nr > 0
1405                                     && (!cover_letter || rev.nr > 1))
1406                                         free(rev.message_id);
1407                                 else
1408                                         string_list_append(rev.ref_message_ids,
1409                                                            rev.message_id);
1410                         }
1411                         gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
1412                 }
1413
1414                 if (!use_stdout && reopen_stdout(numbered_files ? NULL : commit,
1415                                                  &rev, quiet))
1416                         die(_("Failed to create output files"));
1417                 shown = log_tree_commit(&rev, commit);
1418                 free(commit->buffer);
1419                 commit->buffer = NULL;
1420
1421                 /* We put one extra blank line between formatted
1422                  * patches and this flag is used by log-tree code
1423                  * to see if it needs to emit a LF before showing
1424                  * the log; when using one file per patch, we do
1425                  * not want the extra blank line.
1426                  */
1427                 if (!use_stdout)
1428                         rev.shown_one = 0;
1429                 if (shown) {
1430                         if (rev.mime_boundary)
1431                                 printf("\n--%s%s--\n\n\n",
1432                                        mime_boundary_leader,
1433                                        rev.mime_boundary);
1434                         else
1435                                 print_signature();
1436                 }
1437                 if (!use_stdout)
1438                         fclose(stdout);
1439         }
1440         free(list);
1441         free(branch_name);
1442         string_list_clear(&extra_to, 0);
1443         string_list_clear(&extra_cc, 0);
1444         string_list_clear(&extra_hdr, 0);
1445         if (ignore_if_in_upstream)
1446                 free_patch_ids(&ids);
1447         return 0;
1448 }
1449
1450 static int add_pending_commit(const char *arg, struct rev_info *revs, int flags)
1451 {
1452         unsigned char sha1[20];
1453         if (get_sha1(arg, sha1) == 0) {
1454                 struct commit *commit = lookup_commit_reference(sha1);
1455                 if (commit) {
1456                         commit->object.flags |= flags;
1457                         add_pending_object(revs, &commit->object, arg);
1458                         return 0;
1459                 }
1460         }
1461         return -1;
1462 }
1463
1464 static const char * const cherry_usage[] = {
1465         "git cherry [-v] [<upstream> [<head> [<limit>]]]",
1466         NULL
1467 };
1468
1469 static void print_commit(char sign, struct commit *commit, int verbose,
1470                          int abbrev)
1471 {
1472         if (!verbose) {
1473                 printf("%c %s\n", sign,
1474                        find_unique_abbrev(commit->object.sha1, abbrev));
1475         } else {
1476                 struct strbuf buf = STRBUF_INIT;
1477                 pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
1478                 printf("%c %s %s\n", sign,
1479                        find_unique_abbrev(commit->object.sha1, abbrev),
1480                        buf.buf);
1481                 strbuf_release(&buf);
1482         }
1483 }
1484
1485 int cmd_cherry(int argc, const char **argv, const char *prefix)
1486 {
1487         struct rev_info revs;
1488         struct patch_ids ids;
1489         struct commit *commit;
1490         struct commit_list *list = NULL;
1491         struct branch *current_branch;
1492         const char *upstream;
1493         const char *head = "HEAD";
1494         const char *limit = NULL;
1495         int verbose = 0, abbrev = 0;
1496
1497         struct option options[] = {
1498                 OPT__ABBREV(&abbrev),
1499                 OPT__VERBOSE(&verbose, "be verbose"),
1500                 OPT_END()
1501         };
1502
1503         argc = parse_options(argc, argv, prefix, options, cherry_usage, 0);
1504
1505         switch (argc) {
1506         case 3:
1507                 limit = argv[2];
1508                 /* FALLTHROUGH */
1509         case 2:
1510                 head = argv[1];
1511                 /* FALLTHROUGH */
1512         case 1:
1513                 upstream = argv[0];
1514                 break;
1515         default:
1516                 current_branch = branch_get(NULL);
1517                 if (!current_branch || !current_branch->merge
1518                                         || !current_branch->merge[0]
1519                                         || !current_branch->merge[0]->dst) {
1520                         fprintf(stderr, _("Could not find a tracked"
1521                                         " remote branch, please"
1522                                         " specify <upstream> manually.\n"));
1523                         usage_with_options(cherry_usage, options);
1524                 }
1525
1526                 upstream = current_branch->merge[0]->dst;
1527         }
1528
1529         init_revisions(&revs, prefix);
1530         revs.diff = 1;
1531         revs.combine_merges = 0;
1532         revs.ignore_merges = 1;
1533         DIFF_OPT_SET(&revs.diffopt, RECURSIVE);
1534
1535         if (add_pending_commit(head, &revs, 0))
1536                 die(_("Unknown commit %s"), head);
1537         if (add_pending_commit(upstream, &revs, UNINTERESTING))
1538                 die(_("Unknown commit %s"), upstream);
1539
1540         /* Don't say anything if head and upstream are the same. */
1541         if (revs.pending.nr == 2) {
1542                 struct object_array_entry *o = revs.pending.objects;
1543                 if (hashcmp(o[0].item->sha1, o[1].item->sha1) == 0)
1544                         return 0;
1545         }
1546
1547         get_patch_ids(&revs, &ids, prefix);
1548
1549         if (limit && add_pending_commit(limit, &revs, UNINTERESTING))
1550                 die(_("Unknown commit %s"), limit);
1551
1552         /* reverse the list of commits */
1553         if (prepare_revision_walk(&revs))
1554                 die(_("revision walk setup failed"));
1555         while ((commit = get_revision(&revs)) != NULL) {
1556                 /* ignore merges */
1557                 if (commit->parents && commit->parents->next)
1558                         continue;
1559
1560                 commit_list_insert(commit, &list);
1561         }
1562
1563         while (list) {
1564                 char sign = '+';
1565
1566                 commit = list->item;
1567                 if (has_commit_patch_id(commit, &ids))
1568                         sign = '-';
1569                 print_commit(sign, commit, verbose, abbrev);
1570                 list = list->next;
1571         }
1572
1573         free_patch_ids(&ids);
1574         return 0;
1575 }