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