builtin/log.c

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