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