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