Merge branch 'jc/push-cert' into maint
[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, color_reset);
199                 strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
200                 if (decoration->type == DECORATION_REF_TAG)
201                         strbuf_addstr(sb, "tag: ");
202                 strbuf_addstr(sb, decoration->name);
203                 strbuf_addstr(sb, color_reset);
204                 prefix = separator;
205                 decoration = decoration->next;
206         }
207         strbuf_addstr(sb, color_commit);
208         strbuf_addstr(sb, suffix);
209         strbuf_addstr(sb, color_reset);
210 }
211
212 void show_decorations(struct rev_info *opt, struct commit *commit)
213 {
214         struct strbuf sb = STRBUF_INIT;
215
216         if (opt->show_source && commit->util)
217                 printf("\t%s", (char *) commit->util);
218         if (!opt->show_decorations)
219                 return;
220         format_decorations(&sb, commit, opt->diffopt.use_color);
221         fputs(sb.buf, stdout);
222         strbuf_release(&sb);
223 }
224
225 static unsigned int digits_in_number(unsigned int number)
226 {
227         unsigned int i = 10, result = 1;
228         while (i <= number) {
229                 i *= 10;
230                 result++;
231         }
232         return result;
233 }
234
235 void fmt_output_subject(struct strbuf *filename,
236                         const char *subject,
237                         struct rev_info *info)
238 {
239         const char *suffix = info->patch_suffix;
240         int nr = info->nr;
241         int start_len = filename->len;
242         int max_len = start_len + FORMAT_PATCH_NAME_MAX - (strlen(suffix) + 1);
243
244         if (0 < info->reroll_count)
245                 strbuf_addf(filename, "v%d-", info->reroll_count);
246         strbuf_addf(filename, "%04d-%s", nr, subject);
247
248         if (max_len < filename->len)
249                 strbuf_setlen(filename, max_len);
250         strbuf_addstr(filename, suffix);
251 }
252
253 void fmt_output_commit(struct strbuf *filename,
254                        struct commit *commit,
255                        struct rev_info *info)
256 {
257         struct pretty_print_context ctx = {0};
258         struct strbuf subject = STRBUF_INIT;
259
260         format_commit_message(commit, "%f", &subject, &ctx);
261         fmt_output_subject(filename, subject.buf, info);
262         strbuf_release(&subject);
263 }
264
265 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
266                              const char **subject_p,
267                              const char **extra_headers_p,
268                              int *need_8bit_cte_p)
269 {
270         const char *subject = NULL;
271         const char *extra_headers = opt->extra_headers;
272         const char *name = sha1_to_hex(commit->object.sha1);
273
274         *need_8bit_cte_p = 0; /* unknown */
275         if (opt->total > 0) {
276                 static char buffer[64];
277                 snprintf(buffer, sizeof(buffer),
278                          "Subject: [%s%s%0*d/%d] ",
279                          opt->subject_prefix,
280                          *opt->subject_prefix ? " " : "",
281                          digits_in_number(opt->total),
282                          opt->nr, opt->total);
283                 subject = buffer;
284         } else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
285                 static char buffer[256];
286                 snprintf(buffer, sizeof(buffer),
287                          "Subject: [%s] ",
288                          opt->subject_prefix);
289                 subject = buffer;
290         } else {
291                 subject = "Subject: ";
292         }
293
294         printf("From %s Mon Sep 17 00:00:00 2001\n", name);
295         graph_show_oneline(opt->graph);
296         if (opt->message_id) {
297                 printf("Message-Id: <%s>\n", opt->message_id);
298                 graph_show_oneline(opt->graph);
299         }
300         if (opt->ref_message_ids && opt->ref_message_ids->nr > 0) {
301                 int i, n;
302                 n = opt->ref_message_ids->nr;
303                 printf("In-Reply-To: <%s>\n", opt->ref_message_ids->items[n-1].string);
304                 for (i = 0; i < n; i++)
305                         printf("%s<%s>\n", (i > 0 ? "\t" : "References: "),
306                                opt->ref_message_ids->items[i].string);
307                 graph_show_oneline(opt->graph);
308         }
309         if (opt->mime_boundary) {
310                 static char subject_buffer[1024];
311                 static char buffer[1024];
312                 struct strbuf filename =  STRBUF_INIT;
313                 *need_8bit_cte_p = -1; /* NEVER */
314                 snprintf(subject_buffer, sizeof(subject_buffer) - 1,
315                          "%s"
316                          "MIME-Version: 1.0\n"
317                          "Content-Type: multipart/mixed;"
318                          " boundary=\"%s%s\"\n"
319                          "\n"
320                          "This is a multi-part message in MIME "
321                          "format.\n"
322                          "--%s%s\n"
323                          "Content-Type: text/plain; "
324                          "charset=UTF-8; format=fixed\n"
325                          "Content-Transfer-Encoding: 8bit\n\n",
326                          extra_headers ? extra_headers : "",
327                          mime_boundary_leader, opt->mime_boundary,
328                          mime_boundary_leader, opt->mime_boundary);
329                 extra_headers = subject_buffer;
330
331                 if (opt->numbered_files)
332                         strbuf_addf(&filename, "%d", opt->nr);
333                 else
334                         fmt_output_commit(&filename, commit, opt);
335                 snprintf(buffer, sizeof(buffer) - 1,
336                          "\n--%s%s\n"
337                          "Content-Type: text/x-patch;"
338                          " name=\"%s\"\n"
339                          "Content-Transfer-Encoding: 8bit\n"
340                          "Content-Disposition: %s;"
341                          " filename=\"%s\"\n\n",
342                          mime_boundary_leader, opt->mime_boundary,
343                          filename.buf,
344                          opt->no_inline ? "attachment" : "inline",
345                          filename.buf);
346                 opt->diffopt.stat_sep = buffer;
347                 strbuf_release(&filename);
348         }
349         *subject_p = subject;
350         *extra_headers_p = extra_headers;
351 }
352
353 static void show_sig_lines(struct rev_info *opt, int status, const char *bol)
354 {
355         const char *color, *reset, *eol;
356
357         color = diff_get_color_opt(&opt->diffopt,
358                                    status ? DIFF_WHITESPACE : DIFF_FRAGINFO);
359         reset = diff_get_color_opt(&opt->diffopt, DIFF_RESET);
360         while (*bol) {
361                 eol = strchrnul(bol, '\n');
362                 printf("%s%.*s%s%s", color, (int)(eol - bol), bol, reset,
363                        *eol ? "\n" : "");
364                 graph_show_oneline(opt->graph);
365                 bol = (*eol) ? (eol + 1) : eol;
366         }
367 }
368
369 static void show_signature(struct rev_info *opt, struct commit *commit)
370 {
371         struct strbuf payload = STRBUF_INIT;
372         struct strbuf signature = STRBUF_INIT;
373         struct strbuf gpg_output = STRBUF_INIT;
374         int status;
375
376         if (parse_signed_commit(commit, &payload, &signature) <= 0)
377                 goto out;
378
379         status = verify_signed_buffer(payload.buf, payload.len,
380                                       signature.buf, signature.len,
381                                       &gpg_output, NULL);
382         if (status && !gpg_output.len)
383                 strbuf_addstr(&gpg_output, "No signature\n");
384
385         show_sig_lines(opt, status, gpg_output.buf);
386
387  out:
388         strbuf_release(&gpg_output);
389         strbuf_release(&payload);
390         strbuf_release(&signature);
391 }
392
393 static int which_parent(const unsigned char *sha1, const struct commit *commit)
394 {
395         int nth;
396         const struct commit_list *parent;
397
398         for (nth = 0, parent = commit->parents; parent; parent = parent->next) {
399                 if (!hashcmp(parent->item->object.sha1, sha1))
400                         return nth;
401                 nth++;
402         }
403         return -1;
404 }
405
406 static int is_common_merge(const struct commit *commit)
407 {
408         return (commit->parents
409                 && commit->parents->next
410                 && !commit->parents->next->next);
411 }
412
413 static void show_one_mergetag(struct commit *commit,
414                               struct commit_extra_header *extra,
415                               void *data)
416 {
417         struct rev_info *opt = (struct rev_info *)data;
418         unsigned char sha1[20];
419         struct tag *tag;
420         struct strbuf verify_message;
421         int status, nth;
422         size_t payload_size, gpg_message_offset;
423
424         hash_sha1_file(extra->value, extra->len, typename(OBJ_TAG), sha1);
425         tag = lookup_tag(sha1);
426         if (!tag)
427                 return; /* error message already given */
428
429         strbuf_init(&verify_message, 256);
430         if (parse_tag_buffer(tag, extra->value, extra->len))
431                 strbuf_addstr(&verify_message, "malformed mergetag\n");
432         else if (is_common_merge(commit) &&
433                  !hashcmp(tag->tagged->sha1,
434                           commit->parents->next->item->object.sha1))
435                 strbuf_addf(&verify_message,
436                             "merged tag '%s'\n", tag->tag);
437         else if ((nth = which_parent(tag->tagged->sha1, commit)) < 0)
438                 strbuf_addf(&verify_message, "tag %s names a non-parent %s\n",
439                                     tag->tag, tag->tagged->sha1);
440         else
441                 strbuf_addf(&verify_message,
442                             "parent #%d, tagged '%s'\n", nth + 1, tag->tag);
443         gpg_message_offset = verify_message.len;
444
445         payload_size = parse_signature(extra->value, extra->len);
446         status = -1;
447         if (extra->len > payload_size) {
448                 /* could have a good signature */
449                 if (!verify_signed_buffer(extra->value, payload_size,
450                                           extra->value + payload_size,
451                                           extra->len - payload_size,
452                                           &verify_message, NULL))
453                         status = 0; /* good */
454                 else if (verify_message.len <= gpg_message_offset)
455                         strbuf_addstr(&verify_message, "No signature\n");
456                 /* otherwise we couldn't verify, which is shown as bad */
457         }
458
459         show_sig_lines(opt, status, verify_message.buf);
460         strbuf_release(&verify_message);
461 }
462
463 static void show_mergetag(struct rev_info *opt, struct commit *commit)
464 {
465         for_each_mergetag(show_one_mergetag, commit, opt);
466 }
467
468 void show_log(struct rev_info *opt)
469 {
470         struct strbuf msgbuf = STRBUF_INIT;
471         struct log_info *log = opt->loginfo;
472         struct commit *commit = log->commit, *parent = log->parent;
473         int abbrev_commit = opt->abbrev_commit ? opt->abbrev : 40;
474         const char *extra_headers = opt->extra_headers;
475         struct pretty_print_context ctx = {0};
476
477         opt->loginfo = NULL;
478         if (!opt->verbose_header) {
479                 graph_show_commit(opt->graph);
480
481                 if (!opt->graph)
482                         put_revision_mark(opt, commit);
483                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
484                 if (opt->print_parents)
485                         show_parents(commit, abbrev_commit);
486                 if (opt->children.name)
487                         show_children(opt, commit, abbrev_commit);
488                 show_decorations(opt, commit);
489                 if (opt->graph && !graph_is_commit_finished(opt->graph)) {
490                         putchar('\n');
491                         graph_show_remainder(opt->graph);
492                 }
493                 putchar(opt->diffopt.line_termination);
494                 return;
495         }
496
497         /*
498          * If use_terminator is set, we already handled any record termination
499          * at the end of the last record.
500          * Otherwise, add a diffopt.line_termination character before all
501          * entries but the first.  (IOW, as a separator between entries)
502          */
503         if (opt->shown_one && !opt->use_terminator) {
504                 /*
505                  * If entries are separated by a newline, the output
506                  * should look human-readable.  If the last entry ended
507                  * with a newline, print the graph output before this
508                  * newline.  Otherwise it will end up as a completely blank
509                  * line and will look like a gap in the graph.
510                  *
511                  * If the entry separator is not a newline, the output is
512                  * primarily intended for programmatic consumption, and we
513                  * never want the extra graph output before the entry
514                  * separator.
515                  */
516                 if (opt->diffopt.line_termination == '\n' &&
517                     !opt->missing_newline)
518                         graph_show_padding(opt->graph);
519                 putchar(opt->diffopt.line_termination);
520         }
521         opt->shown_one = 1;
522
523         /*
524          * If the history graph was requested,
525          * print the graph, up to this commit's line
526          */
527         graph_show_commit(opt->graph);
528
529         /*
530          * Print header line of header..
531          */
532
533         if (opt->commit_format == CMIT_FMT_EMAIL) {
534                 log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
535                                         &ctx.need_8bit_cte);
536         } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
537                 fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
538                 if (opt->commit_format != CMIT_FMT_ONELINE)
539                         fputs("commit ", stdout);
540
541                 if (!opt->graph)
542                         put_revision_mark(opt, commit);
543                 fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
544                       stdout);
545                 if (opt->print_parents)
546                         show_parents(commit, abbrev_commit);
547                 if (opt->children.name)
548                         show_children(opt, commit, abbrev_commit);
549                 if (parent)
550                         printf(" (from %s)",
551                                find_unique_abbrev(parent->object.sha1,
552                                                   abbrev_commit));
553                 fputs(diff_get_color_opt(&opt->diffopt, DIFF_RESET), stdout);
554                 show_decorations(opt, commit);
555                 if (opt->commit_format == CMIT_FMT_ONELINE) {
556                         putchar(' ');
557                 } else {
558                         putchar('\n');
559                         graph_show_oneline(opt->graph);
560                 }
561                 if (opt->reflog_info) {
562                         /*
563                          * setup_revisions() ensures that opt->reflog_info
564                          * and opt->graph cannot both be set,
565                          * so we don't need to worry about printing the
566                          * graph info here.
567                          */
568                         show_reflog_message(opt->reflog_info,
569                                             opt->commit_format == CMIT_FMT_ONELINE,
570                                             opt->date_mode,
571                                             opt->date_mode_explicit);
572                         if (opt->commit_format == CMIT_FMT_ONELINE)
573                                 return;
574                 }
575         }
576
577         if (opt->show_signature) {
578                 show_signature(opt, commit);
579                 show_mergetag(opt, commit);
580         }
581
582         if (!get_cached_commit_buffer(commit, NULL))
583                 return;
584
585         if (opt->show_notes) {
586                 int raw;
587                 struct strbuf notebuf = STRBUF_INIT;
588
589                 raw = (opt->commit_format == CMIT_FMT_USERFORMAT);
590                 format_display_notes(commit->object.sha1, &notebuf,
591                                      get_log_output_encoding(), raw);
592                 ctx.notes_message = notebuf.len
593                         ? strbuf_detach(&notebuf, NULL)
594                         : xcalloc(1, 1);
595         }
596
597         /*
598          * And then the pretty-printed message itself
599          */
600         if (ctx.need_8bit_cte >= 0 && opt->add_signoff)
601                 ctx.need_8bit_cte =
602                         has_non_ascii(fmt_name(getenv("GIT_COMMITTER_NAME"),
603                                                getenv("GIT_COMMITTER_EMAIL")));
604         ctx.date_mode = opt->date_mode;
605         ctx.date_mode_explicit = opt->date_mode_explicit;
606         ctx.abbrev = opt->diffopt.abbrev;
607         ctx.after_subject = extra_headers;
608         ctx.preserve_subject = opt->preserve_subject;
609         ctx.reflog_info = opt->reflog_info;
610         ctx.fmt = opt->commit_format;
611         ctx.mailmap = opt->mailmap;
612         ctx.color = opt->diffopt.use_color;
613         ctx.output_encoding = get_log_output_encoding();
614         if (opt->from_ident.mail_begin && opt->from_ident.name_begin)
615                 ctx.from_ident = &opt->from_ident;
616         pretty_print_commit(&ctx, commit, &msgbuf);
617
618         if (opt->add_signoff)
619                 append_signoff(&msgbuf, 0, APPEND_SIGNOFF_DEDUP);
620
621         if ((ctx.fmt != CMIT_FMT_USERFORMAT) &&
622             ctx.notes_message && *ctx.notes_message) {
623                 if (ctx.fmt == CMIT_FMT_EMAIL) {
624                         strbuf_addstr(&msgbuf, "---\n");
625                         opt->shown_dashes = 1;
626                 }
627                 strbuf_addstr(&msgbuf, ctx.notes_message);
628         }
629
630         if (opt->show_log_size) {
631                 printf("log size %i\n", (int)msgbuf.len);
632                 graph_show_oneline(opt->graph);
633         }
634
635         /*
636          * Set opt->missing_newline if msgbuf doesn't
637          * end in a newline (including if it is empty)
638          */
639         if (!msgbuf.len || msgbuf.buf[msgbuf.len - 1] != '\n')
640                 opt->missing_newline = 1;
641         else
642                 opt->missing_newline = 0;
643
644         if (opt->graph)
645                 graph_show_commit_msg(opt->graph, &msgbuf);
646         else
647                 fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
648         if (opt->use_terminator && !commit_format_is_empty(opt->commit_format)) {
649                 if (!opt->missing_newline)
650                         graph_show_padding(opt->graph);
651                 putchar(opt->diffopt.line_termination);
652         }
653
654         strbuf_release(&msgbuf);
655         free(ctx.notes_message);
656 }
657
658 int log_tree_diff_flush(struct rev_info *opt)
659 {
660         opt->shown_dashes = 0;
661         diffcore_std(&opt->diffopt);
662
663         if (diff_queue_is_empty()) {
664                 int saved_fmt = opt->diffopt.output_format;
665                 opt->diffopt.output_format = DIFF_FORMAT_NO_OUTPUT;
666                 diff_flush(&opt->diffopt);
667                 opt->diffopt.output_format = saved_fmt;
668                 return 0;
669         }
670
671         if (opt->loginfo && !opt->no_commit_id) {
672                 show_log(opt);
673                 if ((opt->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT) &&
674                     opt->verbose_header &&
675                     opt->commit_format != CMIT_FMT_ONELINE &&
676                     !commit_format_is_empty(opt->commit_format)) {
677                         /*
678                          * When showing a verbose header (i.e. log message),
679                          * and not in --pretty=oneline format, we would want
680                          * an extra newline between the end of log and the
681                          * diff/diffstat output for readability.
682                          */
683                         int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
684                         if (opt->diffopt.output_prefix) {
685                                 struct strbuf *msg = NULL;
686                                 msg = opt->diffopt.output_prefix(&opt->diffopt,
687                                         opt->diffopt.output_prefix_data);
688                                 fwrite(msg->buf, msg->len, 1, stdout);
689                         }
690
691                         /*
692                          * We may have shown three-dashes line early
693                          * between notes and the log message, in which
694                          * case we only want a blank line after the
695                          * notes without (an extra) three-dashes line.
696                          * Otherwise, we show the three-dashes line if
697                          * we are showing the patch with diffstat, but
698                          * in that case, there is no extra blank line
699                          * after the three-dashes line.
700                          */
701                         if (!opt->shown_dashes &&
702                             (pch & opt->diffopt.output_format) == pch)
703                                 printf("---");
704                         putchar('\n');
705                 }
706         }
707         diff_flush(&opt->diffopt);
708         return 1;
709 }
710
711 static int do_diff_combined(struct rev_info *opt, struct commit *commit)
712 {
713         diff_tree_combined_merge(commit, opt->dense_combined_merges, opt);
714         return !opt->loginfo;
715 }
716
717 /*
718  * Show the diff of a commit.
719  *
720  * Return true if we printed any log info messages
721  */
722 static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log_info *log)
723 {
724         int showed_log;
725         struct commit_list *parents;
726         unsigned const char *sha1;
727
728         if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
729                 return 0;
730
731         parse_commit_or_die(commit);
732         sha1 = commit->tree->object.sha1;
733
734         /* Root commit? */
735         parents = get_saved_parents(opt, commit);
736         if (!parents) {
737                 if (opt->show_root_diff) {
738                         diff_root_tree_sha1(sha1, "", &opt->diffopt);
739                         log_tree_diff_flush(opt);
740                 }
741                 return !opt->loginfo;
742         }
743
744         /* More than one parent? */
745         if (parents && parents->next) {
746                 if (opt->ignore_merges)
747                         return 0;
748                 else if (opt->combine_merges)
749                         return do_diff_combined(opt, commit);
750                 else if (opt->first_parent_only) {
751                         /*
752                          * Generate merge log entry only for the first
753                          * parent, showing summary diff of the others
754                          * we merged _in_.
755                          */
756                         parse_commit_or_die(parents->item);
757                         diff_tree_sha1(parents->item->tree->object.sha1,
758                                        sha1, "", &opt->diffopt);
759                         log_tree_diff_flush(opt);
760                         return !opt->loginfo;
761                 }
762
763                 /* If we show individual diffs, show the parent info */
764                 log->parent = parents->item;
765         }
766
767         showed_log = 0;
768         for (;;) {
769                 struct commit *parent = parents->item;
770
771                 parse_commit_or_die(parent);
772                 diff_tree_sha1(parent->tree->object.sha1,
773                                sha1, "", &opt->diffopt);
774                 log_tree_diff_flush(opt);
775
776                 showed_log |= !opt->loginfo;
777
778                 /* Set up the log info for the next parent, if any.. */
779                 parents = parents->next;
780                 if (!parents)
781                         break;
782                 log->parent = parents->item;
783                 opt->loginfo = log;
784         }
785         return showed_log;
786 }
787
788 int log_tree_commit(struct rev_info *opt, struct commit *commit)
789 {
790         struct log_info log;
791         int shown;
792
793         log.commit = commit;
794         log.parent = NULL;
795         opt->loginfo = &log;
796
797         if (opt->line_level_traverse)
798                 return line_log_print(opt, commit);
799
800         if (opt->track_linear && !opt->linear && !opt->reverse_output_stage)
801                 printf("\n%s\n", opt->break_bar);
802         shown = log_tree_diff(opt, commit, &log);
803         if (!shown && opt->loginfo && opt->always_show_header) {
804                 log.parent = NULL;
805                 show_log(opt);
806                 shown = 1;
807         }
808         if (opt->track_linear && !opt->linear && opt->reverse_output_stage)
809                 printf("\n%s\n", opt->break_bar);
810         opt->loginfo = NULL;
811         maybe_flush_or_die(stdout, "stdout");
812         return shown;
813 }