Documentation/git-worktree: associate options with commands
[git] / log-tree.c
1 #include "cache.h"
2 #include "diff.h"
3 #include "commit.h"
4 #include "tag.h"
5 #include "graph.h"
6 #include "log-tree.h"
7 #include "reflog-walk.h"
8 #include "refs.h"
9 #include "string-list.h"
10 #include "color.h"
11 #include "gpg-interface.h"
12 #include "sequencer.h"
13 #include "line-log.h"
14
15 static struct decoration name_decoration = { "object names" };
16
17 static char decoration_colors[][COLOR_MAXLEN] = {
18         GIT_COLOR_RESET,
19         GIT_COLOR_BOLD_GREEN,   /* REF_LOCAL */
20         GIT_COLOR_BOLD_RED,     /* REF_REMOTE */
21         GIT_COLOR_BOLD_YELLOW,  /* REF_TAG */
22         GIT_COLOR_BOLD_MAGENTA, /* REF_STASH */
23         GIT_COLOR_BOLD_CYAN,    /* REF_HEAD */
24         GIT_COLOR_BOLD_BLUE,    /* GRAFTED */
25 };
26
27 static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
28 {
29         if (want_color(decorate_use_color))
30                 return decoration_colors[ix];
31         return "";
32 }
33
34 static int parse_decorate_color_slot(const char *slot)
35 {
36         /*
37          * We're comparing with 'ignore-case' on
38          * (because config.c sets them all tolower),
39          * but let's match the letters in the literal
40          * string values here with how they are
41          * documented in Documentation/config.txt, for
42          * consistency.
43          *
44          * We love being consistent, don't we?
45          */
46         if (!strcasecmp(slot, "branch"))
47                 return DECORATION_REF_LOCAL;
48         if (!strcasecmp(slot, "remoteBranch"))
49                 return DECORATION_REF_REMOTE;
50         if (!strcasecmp(slot, "tag"))
51                 return DECORATION_REF_TAG;
52         if (!strcasecmp(slot, "stash"))
53                 return DECORATION_REF_STASH;
54         if (!strcasecmp(slot, "HEAD"))
55                 return DECORATION_REF_HEAD;
56         return -1;
57 }
58
59 int parse_decorate_color_config(const char *var, const char *slot_name, const char *value)
60 {
61         int slot = parse_decorate_color_slot(slot_name);
62         if (slot < 0)
63                 return 0;
64         if (!value)
65                 return config_error_nonbool(var);
66         return color_parse(value, decoration_colors[slot]);
67 }
68
69 /*
70  * log-tree.c uses DIFF_OPT_TST for determining whether to use color
71  * for showing the commit sha1, use the same check for --decorate
72  */
73 #define decorate_get_color_opt(o, ix) \
74         decorate_get_color((o)->use_color, ix)
75
76 void add_name_decoration(enum decoration_type type, const char *name, struct object *obj)
77 {
78         int nlen = strlen(name);
79         struct name_decoration *res = xmalloc(sizeof(*res) + nlen + 1);
80         memcpy(res->name, name, nlen + 1);
81         res->type = type;
82         res->next = add_decoration(&name_decoration, obj, res);
83 }
84
85 const struct name_decoration *get_name_decoration(const struct object *obj)
86 {
87         return lookup_decoration(&name_decoration, obj);
88 }
89
90 static int add_ref_decoration(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
91 {
92         struct object *obj;
93         enum decoration_type type = DECORATION_NONE;
94
95         if (starts_with(refname, "refs/replace/")) {
96                 unsigned char original_sha1[20];
97                 if (!check_replace_refs)
98                         return 0;
99                 if (get_sha1_hex(refname + 13, original_sha1)) {
100                         warning("invalid replace ref %s", refname);
101                         return 0;
102                 }
103                 obj = parse_object(original_sha1);
104                 if (obj)
105                         add_name_decoration(DECORATION_GRAFTED, "replaced", obj);
106                 return 0;
107         }
108
109         obj = parse_object(sha1);
110         if (!obj)
111                 return 0;
112
113         if (starts_with(refname, "refs/heads/"))
114                 type = DECORATION_REF_LOCAL;
115         else if (starts_with(refname, "refs/remotes/"))
116                 type = DECORATION_REF_REMOTE;
117         else if (starts_with(refname, "refs/tags/"))
118                 type = DECORATION_REF_TAG;
119         else if (!strcmp(refname, "refs/stash"))
120                 type = DECORATION_REF_STASH;
121         else if (!strcmp(refname, "HEAD"))
122                 type = DECORATION_REF_HEAD;
123
124         if (!cb_data || *(int *)cb_data == DECORATE_SHORT_REFS)
125                 refname = prettify_refname(refname);
126         add_name_decoration(type, refname, obj);
127         while (obj->type == OBJ_TAG) {
128                 obj = ((struct tag *)obj)->tagged;
129                 if (!obj)
130                         break;
131                 if (!obj->parsed)
132                         parse_object(obj->sha1);
133                 add_name_decoration(DECORATION_REF_TAG, refname, obj);
134         }
135         return 0;
136 }
137
138 static int add_graft_decoration(const struct commit_graft *graft, void *cb_data)
139 {
140         struct commit *commit = lookup_commit(graft->sha1);
141         if (!commit)
142                 return 0;
143         add_name_decoration(DECORATION_GRAFTED, "grafted", &commit->object);
144         return 0;
145 }
146
147 void load_ref_decorations(int flags)
148 {
149         static int loaded;
150         if (!loaded) {
151                 loaded = 1;
152                 for_each_ref(add_ref_decoration, &flags);
153                 head_ref(add_ref_decoration, &flags);
154                 for_each_commit_graft(add_graft_decoration, NULL);
155         }
156 }
157
158 static void show_parents(struct commit *commit, int abbrev)
159 {
160         struct commit_list *p;
161         for (p = commit->parents; p ; p = p->next) {
162                 struct commit *parent = p->item;
163                 printf(" %s", find_unique_abbrev(parent->object.sha1, abbrev));
164         }
165 }
166
167 static void show_children(struct rev_info *opt, struct commit *commit, int abbrev)
168 {
169         struct commit_list *p = lookup_decoration(&opt->children, &commit->object);
170         for ( ; p; p = p->next) {
171                 printf(" %s", find_unique_abbrev(p->item->object.sha1, abbrev));
172         }
173 }
174
175 /*
176  * The caller makes sure there is no funny color before calling.
177  * format_decorations_extended makes sure the same after return.
178  */
179 void format_decorations_extended(struct strbuf *sb,
180                         const struct commit *commit,
181                         int use_color,
182                         const char *prefix,
183                         const char *separator,
184                         const char *suffix)
185 {
186         const struct name_decoration *decoration;
187         const char *color_commit =
188                 diff_get_color(use_color, DIFF_COMMIT);
189         const char *color_reset =
190                 decorate_get_color(use_color, DECORATION_NONE);
191
192         decoration = get_name_decoration(&commit->object);
193         if (!decoration)
194                 return;
195         while (decoration) {
196                 strbuf_addstr(sb, color_commit);
197                 strbuf_addstr(sb, prefix);
198                 strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
199                 if (decoration->type == DECORATION_REF_TAG)
200                         strbuf_addstr(sb, "tag: ");
201                 strbuf_addstr(sb, decoration->name);
202                 strbuf_addstr(sb, color_reset);
203                 prefix = separator;
204                 decoration = decoration->next;
205         }
206         strbuf_addstr(sb, color_commit);
207         strbuf_addstr(sb, suffix);
208         strbuf_addstr(sb, color_reset);
209 }
210
211 void show_decorations(struct rev_info *opt, struct commit *commit)
212 {
213         struct strbuf sb = STRBUF_INIT;
214
215         if (opt->show_source && commit->util)
216                 printf("\t%s", (char *) commit->util);
217         if (!opt->show_decorations)
218                 return;
219         format_decorations(&sb, commit, opt->diffopt.use_color);
220         fputs(sb.buf, stdout);
221         strbuf_release(&sb);
222 }
223
224 static unsigned int digits_in_number(unsigned int number)
225 {
226         unsigned int i = 10, result = 1;
227         while (i <= number) {
228                 i *= 10;
229                 result++;
230         }
231         return result;
232 }
233
234 void fmt_output_subject(struct strbuf *filename,
235                         const char *subject,
236                         struct rev_info *info)
237 {
238         const char *suffix = info->patch_suffix;
239         int nr = info->nr;
240         int start_len = filename->len;
241         int max_len = start_len + FORMAT_PATCH_NAME_MAX - (strlen(suffix) + 1);
242
243         if (0 < info->reroll_count)
244                 strbuf_addf(filename, "v%d-", info->reroll_count);
245         strbuf_addf(filename, "%04d-%s", nr, subject);
246
247         if (max_len < filename->len)
248                 strbuf_setlen(filename, max_len);
249         strbuf_addstr(filename, suffix);
250 }
251
252 void fmt_output_commit(struct strbuf *filename,
253                        struct commit *commit,
254                        struct rev_info *info)
255 {
256         struct pretty_print_context ctx = {0};
257         struct strbuf subject = STRBUF_INIT;
258
259         format_commit_message(commit, "%f", &subject, &ctx);
260         fmt_output_subject(filename, subject.buf, info);
261         strbuf_release(&subject);
262 }
263
264 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
265                              const char **subject_p,
266                              const char **extra_headers_p,
267                              int *need_8bit_cte_p)
268 {
269         const char *subject = NULL;
270         const char *extra_headers = opt->extra_headers;
271         const char *name = sha1_to_hex(commit->object.sha1);
272
273         *need_8bit_cte_p = 0; /* unknown */
274         if (opt->total > 0) {
275                 static char buffer[64];
276                 snprintf(buffer, sizeof(buffer),
277                          "Subject: [%s%s%0*d/%d] ",
278                          opt->subject_prefix,
279                          *opt->subject_prefix ? " " : "",
280                          digits_in_number(opt->total),
281                          opt->nr, opt->total);
282                 subject = buffer;
283         } else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
284                 static char buffer[256];
285                 snprintf(buffer, sizeof(buffer),
286                          "Subject: [%s] ",
287                          opt->subject_prefix);
288                 subject = buffer;
289         } else {
290                 subject = "Subject: ";
291         }
292
293         printf("From %s Mon Sep 17 00:00:00 2001\n", name);
294         graph_show_oneline(opt->graph);
295         if (opt->message_id) {
296                 printf("Message-Id: <%s>\n", opt->message_id);
297                 graph_show_oneline(opt->graph);
298         }
299         if (opt->ref_message_ids && opt->ref_message_ids->nr > 0) {
300                 int i, n;
301                 n = opt->ref_message_ids->nr;
302                 printf("In-Reply-To: <%s>\n", opt->ref_message_ids->items[n-1].string);
303                 for (i = 0; i < n; i++)
304                         printf("%s<%s>\n", (i > 0 ? "\t" : "References: "),
305                                opt->ref_message_ids->items[i].string);
306                 graph_show_oneline(opt->graph);
307         }
308         if (opt->mime_boundary) {
309                 static char subject_buffer[1024];
310                 static char buffer[1024];
311                 struct strbuf filename =  STRBUF_INIT;
312                 *need_8bit_cte_p = -1; /* NEVER */
313                 snprintf(subject_buffer, sizeof(subject_buffer) - 1,
314                          "%s"
315                          "MIME-Version: 1.0\n"
316                          "Content-Type: multipart/mixed;"
317                          " boundary=\"%s%s\"\n"
318                          "\n"
319                          "This is a multi-part message in MIME "
320                          "format.\n"
321                          "--%s%s\n"
322                          "Content-Type: text/plain; "
323                          "charset=UTF-8; format=fixed\n"
324                          "Content-Transfer-Encoding: 8bit\n\n",
325                          extra_headers ? extra_headers : "",
326                          mime_boundary_leader, opt->mime_boundary,
327                          mime_boundary_leader, opt->mime_boundary);
328                 extra_headers = subject_buffer;
329
330                 if (opt->numbered_files)
331                         strbuf_addf(&filename, "%d", opt->nr);
332                 else
333                         fmt_output_commit(&filename, commit, opt);
334                 snprintf(buffer, sizeof(buffer) - 1,
335                          "\n--%s%s\n"
336                          "Content-Type: text/x-patch;"
337                          " name=\"%s\"\n"
338                          "Content-Transfer-Encoding: 8bit\n"
339                          "Content-Disposition: %s;"
340                          " filename=\"%s\"\n\n",
341                          mime_boundary_leader, opt->mime_boundary,
342                          filename.buf,
343                          opt->no_inline ? "attachment" : "inline",
344                          filename.buf);
345                 opt->diffopt.stat_sep = buffer;
346                 strbuf_release(&filename);
347         }
348         *subject_p = subject;
349         *extra_headers_p = extra_headers;
350 }
351
352 static void show_sig_lines(struct rev_info *opt, int status, const char *bol)
353 {
354         const char *color, *reset, *eol;
355
356         color = diff_get_color_opt(&opt->diffopt,
357                                    status ? DIFF_WHITESPACE : DIFF_FRAGINFO);
358         reset = diff_get_color_opt(&opt->diffopt, DIFF_RESET);
359         while (*bol) {
360                 eol = strchrnul(bol, '\n');
361                 printf("%s%.*s%s%s", color, (int)(eol - bol), bol, reset,
362                        *eol ? "\n" : "");
363                 graph_show_oneline(opt->graph);
364                 bol = (*eol) ? (eol + 1) : eol;
365         }
366 }
367
368 static void show_signature(struct rev_info *opt, struct commit *commit)
369 {
370         struct strbuf payload = STRBUF_INIT;
371         struct strbuf signature = STRBUF_INIT;
372         struct strbuf gpg_output = STRBUF_INIT;
373         int status;
374
375         if (parse_signed_commit(commit, &payload, &signature) <= 0)
376                 goto out;
377
378         status = verify_signed_buffer(payload.buf, payload.len,
379                                       signature.buf, signature.len,
380                                       &gpg_output, NULL);
381         if (status && !gpg_output.len)
382                 strbuf_addstr(&gpg_output, "No signature\n");
383
384         show_sig_lines(opt, status, gpg_output.buf);
385
386  out:
387         strbuf_release(&gpg_output);
388         strbuf_release(&payload);
389         strbuf_release(&signature);
390 }
391
392 static int which_parent(const unsigned char *sha1, const struct commit *commit)
393 {
394         int nth;
395         const struct commit_list *parent;
396
397         for (nth = 0, parent = commit->parents; parent; parent = parent->next) {
398                 if (!hashcmp(parent->item->object.sha1, sha1))
399                         return nth;
400                 nth++;
401         }
402         return -1;
403 }
404
405 static int is_common_merge(const struct commit *commit)
406 {
407         return (commit->parents
408                 && commit->parents->next
409                 && !commit->parents->next->next);
410 }
411
412 static void show_one_mergetag(struct commit *commit,
413                               struct commit_extra_header *extra,
414                               void *data)
415 {
416         struct rev_info *opt = (struct rev_info *)data;
417         unsigned char sha1[20];
418         struct tag *tag;
419         struct strbuf verify_message;
420         int status, nth;
421         size_t payload_size, gpg_message_offset;
422
423         hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), sha1);
424         tag = lookup_tag(sha1);
425         if (!tag)
426                 return; /* error message already given */
427
428         strbuf_init(&verify_message, 256);
429         if (parse_tag_buffer(tag, extra->value, extra->len))
430                 strbuf_addstr(&verify_message, "malformed mergetag\n");
431         else if (is_common_merge(commit) &&
432                  !hashcmp(tag->tagged->sha1,
433                           commit->parents->next->item->object.sha1))
434                 strbuf_addf(&verify_message,
435                             "merged tag '%s'\n", tag->tag);
436         else if ((nth = which_parent(tag->tagged->sha1, commit)) < 0)
437                 strbuf_addf(&verify_message, "tag %s names a non-parent %s\n",
438                                     tag->tag, tag->tagged->sha1);
439         else
440                 strbuf_addf(&verify_message,
441                             "parent #%d, tagged '%s'\n", nth + 1, tag->tag);
442         gpg_message_offset = verify_message.len;
443
444         payload_size = parse_signature(extra->value, extra->len);
445         status = -1;
446         if (extra->len > payload_size) {
447                 /* could have a good signature */
448                 if (!verify_signed_buffer(extra->value, payload_size,
449                                           extra->value + payload_size,
450                                           extra->len - payload_size,
451                                           &verify_message, NULL))
452                         status = 0; /* good */
453                 else if (verify_message.len <= gpg_message_offset)
454                         strbuf_addstr(&verify_message, "No signature\n");
455                 /* otherwise we couldn't verify, which is shown as bad */
456         }
457
458         show_sig_lines(opt, status, verify_message.buf);
459         strbuf_release(&verify_message);
460 }
461
462 static void show_mergetag(struct rev_info *opt, struct commit *commit)
463 {
464         for_each_mergetag(show_one_mergetag, commit, opt);
465 }
466
467 void show_log(struct rev_info *opt)
468 {
469         struct strbuf msgbuf = STRBUF_INIT;
470         struct log_info *log = opt->loginfo;
471         struct commit *commit = log->commit, *parent = log->parent;
472         int abbrev_commit = opt->abbrev_commit ? opt->abbrev : 40;
473         const char *extra_headers = opt->extra_headers;
474         struct pretty_print_context ctx = {0};
475
476         opt->loginfo = NULL;
477         if (!opt->verbose_header) {
478                 graph_show_commit(opt->graph);
479
480                 if (!opt->graph)
481                         put_revision_mark(opt, commit);
482                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
483                 if (opt->print_parents)
484                         show_parents(commit, abbrev_commit);
485                 if (opt->children.name)
486                         show_children(opt, commit, abbrev_commit);
487                 show_decorations(opt, commit);
488                 if (opt->graph && !graph_is_commit_finished(opt->graph)) {
489                         putchar('\n');
490                         graph_show_remainder(opt->graph);
491                 }
492                 putchar(opt->diffopt.line_termination);
493                 return;
494         }
495
496         /*
497          * If use_terminator is set, we already handled any record termination
498          * at the end of the last record.
499          * Otherwise, add a diffopt.line_termination character before all
500          * entries but the first.  (IOW, as a separator between entries)
501          */
502         if (opt->shown_one && !opt->use_terminator) {
503                 /*
504                  * If entries are separated by a newline, the output
505                  * should look human-readable.  If the last entry ended
506                  * with a newline, print the graph output before this
507                  * newline.  Otherwise it will end up as a completely blank
508                  * line and will look like a gap in the graph.
509                  *
510                  * If the entry separator is not a newline, the output is
511                  * primarily intended for programmatic consumption, and we
512                  * never want the extra graph output before the entry
513                  * separator.
514                  */
515                 if (opt->diffopt.line_termination == '\n' &&
516                     !opt->missing_newline)
517                         graph_show_padding(opt->graph);
518                 putchar(opt->diffopt.line_termination);
519         }
520         opt->shown_one = 1;
521
522         /*
523          * If the history graph was requested,
524          * print the graph, up to this commit's line
525          */
526         graph_show_commit(opt->graph);
527
528         /*
529          * Print header line of header..
530          */
531
532         if (opt->commit_format == CMIT_FMT_EMAIL) {
533                 log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
534                                         &ctx.need_8bit_cte);
535         } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
536                 fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
537                 if (opt->commit_format != CMIT_FMT_ONELINE)
538                         fputs("commit ", stdout);
539
540                 if (!opt->graph)
541                         put_revision_mark(opt, commit);
542                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
543                       stdout);
544                 if (opt->print_parents)
545                         show_parents(commit, abbrev_commit);
546                 if (opt->children.name)
547                         show_children(opt, commit, abbrev_commit);
548                 if (parent)
549                         printf(" (from %s)",
550                                find_unique_abbrev(parent->object.sha1,
551                                                   abbrev_commit));
552                 fputs(diff_get_color_opt(&opt->diffopt, DIFF_RESET), stdout);
553                 show_decorations(opt, commit);
554                 if (opt->commit_format == CMIT_FMT_ONELINE) {
555                         putchar(' ');
556                 } else {
557                         putchar('\n');
558                         graph_show_oneline(opt->graph);
559                 }
560                 if (opt->reflog_info) {
561                         /*
562                          * setup_revisions() ensures that opt->reflog_info
563                          * and opt->graph cannot both be set,
564                          * so we don't need to worry about printing the
565                          * graph info here.
566                          */
567                         show_reflog_message(opt->reflog_info,
568                                             opt->commit_format == CMIT_FMT_ONELINE,
569                                             opt->date_mode,
570                                             opt->date_mode_explicit);
571                         if (opt->commit_format == CMIT_FMT_ONELINE)
572                                 return;
573                 }
574         }
575
576         if (opt->show_signature) {
577                 show_signature(opt, commit);
578                 show_mergetag(opt, commit);
579         }
580
581         if (!get_cached_commit_buffer(commit, NULL))
582                 return;
583
584         if (opt->show_notes) {
585                 int raw;
586                 struct strbuf notebuf = STRBUF_INIT;
587
588                 raw = (opt->commit_format == CMIT_FMT_USERFORMAT);
589                 format_display_notes(commit->object.sha1, &notebuf,
590                                      get_log_output_encoding(), raw);
591                 ctx.notes_message = notebuf.len
592                         ? strbuf_detach(&notebuf, NULL)
593                         : xcalloc(1, 1);
594         }
595
596         /*
597          * And then the pretty-printed message itself
598          */
599         if (ctx.need_8bit_cte >= 0 && opt->add_signoff)
600                 ctx.need_8bit_cte =
601                         has_non_ascii(fmt_name(getenv("GIT_COMMITTER_NAME"),
602                                                getenv("GIT_COMMITTER_EMAIL")));
603         ctx.date_mode = opt->date_mode;
604         ctx.date_mode_explicit = opt->date_mode_explicit;
605         ctx.abbrev = opt->diffopt.abbrev;
606         ctx.after_subject = extra_headers;
607         ctx.preserve_subject = opt->preserve_subject;
608         ctx.reflog_info = opt->reflog_info;
609         ctx.fmt = opt->commit_format;
610         ctx.mailmap = opt->mailmap;
611         ctx.color = opt->diffopt.use_color;
612         ctx.output_encoding = get_log_output_encoding();
613         if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
614                 ctx.from_ident = &opt->from_ident;
615         pretty_print_commit(&ctx, commit, &msgbuf);
616
617         if (opt->add_signoff)
618                 append_signoff(&msgbuf, 0, APPEND_SIGNOFF_DEDUP);
619
620         if ((ctx.fmt != CMIT_FMT_USERFORMAT) &&
621             ctx.notes_message && *ctx.notes_message) {
622                 if (ctx.fmt == CMIT_FMT_EMAIL) {
623                         strbuf_addstr(&msgbuf, "---\n");
624                         opt->shown_dashes = 1;
625                 }
626                 strbuf_addstr(&msgbuf, ctx.notes_message);
627         }
628
629         if (opt->show_log_size) {
630                 printf("log size %i\n", (int)msgbuf.len);
631                 graph_show_oneline(opt->graph);
632         }
633
634         /*
635          * Set opt->missing_newline if msgbuf doesn't
636          * end in a newline (including if it is empty)
637          */
638         if (!msgbuf.len || msgbuf.buf[msgbuf.len - 1] != '\n')
639                 opt->missing_newline = 1;
640         else
641                 opt->missing_newline = 0;
642
643         if (opt->graph)
644                 graph_show_commit_msg(opt->graph, &msgbuf);
645         else
646                 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
647         if (opt->use_terminator && !commit_format_is_empty(opt->commit_format)) {
648                 if (!opt->missing_newline)
649                         graph_show_padding(opt->graph);
650                 putchar(opt->diffopt.line_termination);
651         }
652
653         strbuf_release(&msgbuf);
654         free(ctx.notes_message);
655 }
656
657 int log_tree_diff_flush(struct rev_info *opt)
658 {
659         opt->shown_dashes = 0;
660         diffcore_std(&opt->diffopt);
661
662         if (diff_queue_is_empty()) {
663                 int saved_fmt = opt->diffopt.output_format;
664                 opt->diffopt.output_format = DIFF_FORMAT_NO_OUTPUT;
665                 diff_flush(&opt->diffopt);
666                 opt->diffopt.output_format = saved_fmt;
667                 return 0;
668         }
669
670         if (opt->loginfo && !opt->no_commit_id) {
671                 show_log(opt);
672                 if ((opt->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT) &&
673                     opt->verbose_header &&
674                     opt->commit_format != CMIT_FMT_ONELINE &&
675                     !commit_format_is_empty(opt->commit_format)) {
676                         /*
677                          * When showing a verbose header (i.e. log message),
678                          * and not in --pretty=oneline format, we would want
679                          * an extra newline between the end of log and the
680                          * diff/diffstat output for readability.
681                          */
682                         int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
683                         if (opt->diffopt.output_prefix) {
684                                 struct strbuf *msg = NULL;
685                                 msg = opt->diffopt.output_prefix(&opt->diffopt,
686                                         opt->diffopt.output_prefix_data);
687                                 fwrite(msg->buf, msg->len, 1, stdout);
688                         }
689
690                         /*
691                          * We may have shown three-dashes line early
692                          * between notes and the log message, in which
693                          * case we only want a blank line after the
694                          * notes without (an extra) three-dashes line.
695                          * Otherwise, we show the three-dashes line if
696                          * we are showing the patch with diffstat, but
697                          * in that case, there is no extra blank line
698                          * after the three-dashes line.
699                          */
700                         if (!opt->shown_dashes &&
701                             (pch & opt->diffopt.output_format) == pch)
702                                 printf("---");
703                         putchar('\n');
704                 }
705         }
706         diff_flush(&opt->diffopt);
707         return 1;
708 }
709
710 static int do_diff_combined(struct rev_info *opt, struct commit *commit)
711 {
712         diff_tree_combined_merge(commit, opt->dense_combined_merges, opt);
713         return !opt->loginfo;
714 }
715
716 /*
717  * Show the diff of a commit.
718  *
719  * Return true if we printed any log info messages
720  */
721 static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log_info *log)
722 {
723         int showed_log;
724         struct commit_list *parents;
725         unsigned const char *sha1;
726
727         if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
728                 return 0;
729
730         parse_commit_or_die(commit);
731         sha1 = commit->tree->object.sha1;
732
733         /* Root commit? */
734         parents = get_saved_parents(opt, commit);
735         if (!parents) {
736                 if (opt->show_root_diff) {
737                         diff_root_tree_sha1(sha1, "", &opt->diffopt);
738                         log_tree_diff_flush(opt);
739                 }
740                 return !opt->loginfo;
741         }
742
743         /* More than one parent? */
744         if (parents && parents->next) {
745                 if (opt->ignore_merges)
746                         return 0;
747                 else if (opt->combine_merges)
748                         return do_diff_combined(opt, commit);
749                 else if (opt->first_parent_only) {
750                         /*
751                          * Generate merge log entry only for the first
752                          * parent, showing summary diff of the others
753                          * we merged _in_.
754                          */
755                         parse_commit_or_die(parents->item);
756                         diff_tree_sha1(parents->item->tree->object.sha1,
757                                        sha1, "", &opt->diffopt);
758                         log_tree_diff_flush(opt);
759                         return !opt->loginfo;
760                 }
761
762                 /* If we show individual diffs, show the parent info */
763                 log->parent = parents->item;
764         }
765
766         showed_log = 0;
767         for (;;) {
768                 struct commit *parent = parents->item;
769
770                 parse_commit_or_die(parent);
771                 diff_tree_sha1(parent->tree->object.sha1,
772                                sha1, "", &opt->diffopt);
773                 log_tree_diff_flush(opt);
774
775                 showed_log |= !opt->loginfo;
776
777                 /* Set up the log info for the next parent, if any.. */
778                 parents = parents->next;
779                 if (!parents)
780                         break;
781                 log->parent = parents->item;
782                 opt->loginfo = log;
783         }
784         return showed_log;
785 }
786
787 int log_tree_commit(struct rev_info *opt, struct commit *commit)
788 {
789         struct log_info log;
790         int shown;
791
792         log.commit = commit;
793         log.parent = NULL;
794         opt->loginfo = &log;
795
796         if (opt->line_level_traverse)
797                 return line_log_print(opt, commit);
798
799         if (opt->track_linear && !opt->linear && !opt->reverse_output_stage)
800                 printf("\n%s\n", opt->break_bar);
801         shown = log_tree_diff(opt, commit, &log);
802         if (!shown && opt->loginfo && opt->always_show_header) {
803                 log.parent = NULL;
804                 show_log(opt);
805                 shown = 1;
806         }
807         if (opt->track_linear && !opt->linear && opt->reverse_output_stage)
808                 printf("\n%s\n", opt->break_bar);
809         opt->loginfo = NULL;
810         maybe_flush_or_die(stdout, "stdout");
811         return shown;
812 }