git.oblomov.eu Git - git/blob - builtin/fmt-merge-msg.c

   1 #include "builtin.h"
   2 #include "cache.h"
   3 #include "config.h"
   4 #include "refs.h"
   5 #include "object-store.h"
   6 #include "commit.h"
   7 #include "diff.h"
   8 #include "revision.h"
   9 #include "tag.h"
  10 #include "string-list.h"
  11 #include "branch.h"
  12 #include "fmt-merge-msg.h"
  13 #include "gpg-interface.h"
  14 #include "repository.h"
  15 #include "commit-reach.h"
  16
  17 static const char * const fmt_merge_msg_usage[] = {
  18         N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
  19         NULL
  20 };
  21
  22 static int use_branch_desc;
  23
  24 int fmt_merge_msg_config(const char *key, const char *value, void *cb)
  25 {
  26         if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
  27                 int is_bool;
  28                 merge_log_config = git_config_bool_or_int(key, value, &is_bool);
  29                 if (!is_bool && merge_log_config < 0)
  30                         return error("%s: negative length %s", key, value);
  31                 if (is_bool && merge_log_config)
  32                         merge_log_config = DEFAULT_MERGE_LOG_LEN;
  33         } else if (!strcmp(key, "merge.branchdesc")) {
  34                 use_branch_desc = git_config_bool(key, value);
  35         } else {
  36                 return git_default_config(key, value, cb);
  37         }
  38         return 0;
  39 }
  40
  41 /* merge data per repository where the merged tips came from */
  42 struct src_data {
  43         struct string_list branch, tag, r_branch, generic;
  44         int head_status;
  45 };
  46
  47 struct origin_data {
  48         struct object_id oid;
  49         unsigned is_local_branch:1;
  50 };
  51
  52 static void init_src_data(struct src_data *data)
  53 {
  54         data->branch.strdup_strings = 1;
  55         data->tag.strdup_strings = 1;
  56         data->r_branch.strdup_strings = 1;
  57         data->generic.strdup_strings = 1;
  58 }
  59
  60 static struct string_list srcs = STRING_LIST_INIT_DUP;
  61 static struct string_list origins = STRING_LIST_INIT_DUP;
  62
  63 struct merge_parents {
  64         int alloc, nr;
  65         struct merge_parent {
  66                 struct object_id given;
  67                 struct object_id commit;
  68                 unsigned char used;
  69         } *item;
  70 };
  71
  72 /*
  73  * I know, I know, this is inefficient, but you won't be pulling and merging
  74  * hundreds of heads at a time anyway.
  75  */
  76 static struct merge_parent *find_merge_parent(struct merge_parents *table,
  77                                               struct object_id *given,
  78                                               struct object_id *commit)
  79 {
  80         int i;
  81         for (i = 0; i < table->nr; i++) {
  82                 if (given && !oideq(&table->item[i].given, given))
  83                         continue;
  84                 if (commit && !oideq(&table->item[i].commit, commit))
  85                         continue;
  86                 return &table->item[i];
  87         }
  88         return NULL;
  89 }
  90
  91 static void add_merge_parent(struct merge_parents *table,
  92                              struct object_id *given,
  93                              struct object_id *commit)
  94 {
  95         if (table->nr && find_merge_parent(table, given, commit))
  96                 return;
  97         ALLOC_GROW(table->item, table->nr + 1, table->alloc);
  98         oidcpy(&table->item[table->nr].given, given);
  99         oidcpy(&table->item[table->nr].commit, commit);
 100         table->item[table->nr].used = 0;
 101         table->nr++;
 102 }
 103
 104 static int handle_line(char *line, struct merge_parents *merge_parents)
 105 {
 106         int i, len = strlen(line);
 107         struct origin_data *origin_data;
 108         char *src;
 109         const char *origin;
 110         struct src_data *src_data;
 111         struct string_list_item *item;
 112         int pulling_head = 0;
 113         struct object_id oid;
 114         const unsigned hexsz = the_hash_algo->hexsz;
 115
 116         if (len < hexsz + 3 || line[hexsz] != '\t')
 117                 return 1;
 118
 119         if (starts_with(line + hexsz + 1, "not-for-merge"))
 120                 return 0;
 121
 122         if (line[hexsz + 1] != '\t')
 123                 return 2;
 124
 125         i = get_oid_hex(line, &oid);
 126         if (i)
 127                 return 3;
 128
 129         if (!find_merge_parent(merge_parents, &oid, NULL))
 130                 return 0; /* subsumed by other parents */
 131
 132         origin_data = xcalloc(1, sizeof(struct origin_data));
 133         oidcpy(&origin_data->oid, &oid);
 134
 135         if (line[len - 1] == '\n')
 136                 line[len - 1] = 0;
 137         line += hexsz + 2;
 138
 139         /*
 140          * At this point, line points at the beginning of comment e.g.
 141          * "branch 'frotz' of git://that/repository.git".
 142          * Find the repository name and point it with src.
 143          */
 144         src = strstr(line, " of ");
 145         if (src) {
 146                 *src = 0;
 147                 src += 4;
 148                 pulling_head = 0;
 149         } else {
 150                 src = line;
 151                 pulling_head = 1;
 152         }
 153
 154         item = unsorted_string_list_lookup(&srcs, src);
 155         if (!item) {
 156                 item = string_list_append(&srcs, src);
 157                 item->util = xcalloc(1, sizeof(struct src_data));
 158                 init_src_data(item->util);
 159         }
 160         src_data = item->util;
 161
 162         if (pulling_head) {
 163                 origin = src;
 164                 src_data->head_status |= 1;
 165         } else if (starts_with(line, "branch ")) {
 166                 origin_data->is_local_branch = 1;
 167                 origin = line + 7;
 168                 string_list_append(&src_data->branch, origin);
 169                 src_data->head_status |= 2;
 170         } else if (starts_with(line, "tag ")) {
 171                 origin = line;
 172                 string_list_append(&src_data->tag, origin + 4);
 173                 src_data->head_status |= 2;
 174         } else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
 175                 string_list_append(&src_data->r_branch, origin);
 176                 src_data->head_status |= 2;
 177         } else {
 178                 origin = src;
 179                 string_list_append(&src_data->generic, line);
 180                 src_data->head_status |= 2;
 181         }
 182
 183         if (!strcmp(".", src) || !strcmp(src, origin)) {
 184                 int len = strlen(origin);
 185                 if (origin[0] == '\'' && origin[len - 1] == '\'')
 186                         origin = xmemdupz(origin + 1, len - 2);
 187         } else
 188                 origin = xstrfmt("%s of %s", origin, src);
 189         if (strcmp(".", src))
 190                 origin_data->is_local_branch = 0;
 191         string_list_append(&origins, origin)->util = origin_data;
 192         return 0;
 193 }
 194
 195 static void print_joined(const char *singular, const char *plural,
 196                 struct string_list *list, struct strbuf *out)
 197 {
 198         if (list->nr == 0)
 199                 return;
 200         if (list->nr == 1) {
 201                 strbuf_addf(out, "%s%s", singular, list->items[0].string);
 202         } else {
 203                 int i;
 204                 strbuf_addstr(out, plural);
 205                 for (i = 0; i < list->nr - 1; i++)
 206                         strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
 207                                     list->items[i].string);
 208                 strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
 209         }
 210 }
 211
 212 static void add_branch_desc(struct strbuf *out, const char *name)
 213 {
 214         struct strbuf desc = STRBUF_INIT;
 215
 216         if (!read_branch_desc(&desc, name)) {
 217                 const char *bp = desc.buf;
 218                 while (*bp) {
 219                         const char *ep = strchrnul(bp, '\n');
 220                         if (*ep)
 221                                 ep++;
 222                         strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
 223                         bp = ep;
 224                 }
 225                 strbuf_complete_line(out);
 226         }
 227         strbuf_release(&desc);
 228 }
 229
 230 #define util_as_integral(elem) ((intptr_t)((elem)->util))
 231
 232 static void record_person_from_buf(int which, struct string_list *people,
 233                                    const char *buffer)
 234 {
 235         char *name_buf, *name, *name_end;
 236         struct string_list_item *elem;
 237         const char *field;
 238
 239         field = (which == 'a') ? "\nauthor " : "\ncommitter ";
 240         name = strstr(buffer, field);
 241         if (!name)
 242                 return;
 243         name += strlen(field);
 244         name_end = strchrnul(name, '<');
 245         if (*name_end)
 246                 name_end--;
 247         while (isspace(*name_end) && name <= name_end)
 248                 name_end--;
 249         if (name_end < name)
 250                 return;
 251         name_buf = xmemdupz(name, name_end - name + 1);
 252
 253         elem = string_list_lookup(people, name_buf);
 254         if (!elem) {
 255                 elem = string_list_insert(people, name_buf);
 256                 elem->util = (void *)0;
 257         }
 258         elem->util = (void*)(util_as_integral(elem) + 1);
 259         free(name_buf);
 260 }
 261
 262
 263 static void record_person(int which, struct string_list *people,
 264                           struct commit *commit)
 265 {
 266         const char *buffer = get_commit_buffer(commit, NULL);
 267         record_person_from_buf(which, people, buffer);
 268         unuse_commit_buffer(commit, buffer);
 269 }
 270
 271 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
 272 {
 273         const struct string_list_item *a = a_, *b = b_;
 274         return util_as_integral(b) - util_as_integral(a);
 275 }
 276
 277 static void add_people_count(struct strbuf *out, struct string_list *people)
 278 {
 279         if (people->nr == 1)
 280                 strbuf_addstr(out, people->items[0].string);
 281         else if (people->nr == 2)
 282                 strbuf_addf(out, "%s (%d) and %s (%d)",
 283                             people->items[0].string,
 284                             (int)util_as_integral(&people->items[0]),
 285                             people->items[1].string,
 286                             (int)util_as_integral(&people->items[1]));
 287         else if (people->nr)
 288                 strbuf_addf(out, "%s (%d) and others",
 289                             people->items[0].string,
 290                             (int)util_as_integral(&people->items[0]));
 291 }
 292
 293 static void credit_people(struct strbuf *out,
 294                           struct string_list *them,
 295                           int kind)
 296 {
 297         const char *label;
 298         const char *me;
 299
 300         if (kind == 'a') {
 301                 label = "By";
 302                 me = git_author_info(IDENT_NO_DATE);
 303         } else {
 304                 label = "Via";
 305                 me = git_committer_info(IDENT_NO_DATE);
 306         }
 307
 308         if (!them->nr ||
 309             (them->nr == 1 &&
 310              me &&
 311              skip_prefix(me, them->items->string, &me) &&
 312              starts_with(me, " <")))
 313                 return;
 314         strbuf_addf(out, "\n%c %s ", comment_line_char, label);
 315         add_people_count(out, them);
 316 }
 317
 318 static void add_people_info(struct strbuf *out,
 319                             struct string_list *authors,
 320                             struct string_list *committers)
 321 {
 322         QSORT(authors->items, authors->nr,
 323               cmp_string_list_util_as_integral);
 324         QSORT(committers->items, committers->nr,
 325               cmp_string_list_util_as_integral);
 326
 327         credit_people(out, authors, 'a');
 328         credit_people(out, committers, 'c');
 329 }
 330
 331 static void shortlog(const char *name,
 332                      struct origin_data *origin_data,
 333                      struct commit *head,
 334                      struct rev_info *rev,
 335                      struct fmt_merge_msg_opts *opts,
 336                      struct strbuf *out)
 337 {
 338         int i, count = 0;
 339         struct commit *commit;
 340         struct object *branch;
 341         struct string_list subjects = STRING_LIST_INIT_DUP;
 342         struct string_list authors = STRING_LIST_INIT_DUP;
 343         struct string_list committers = STRING_LIST_INIT_DUP;
 344         int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 345         struct strbuf sb = STRBUF_INIT;
 346         const struct object_id *oid = &origin_data->oid;
 347         int limit = opts->shortlog_len;
 348
 349         branch = deref_tag(the_repository, parse_object(the_repository, oid),
 350                            oid_to_hex(oid),
 351                            the_hash_algo->hexsz);
 352         if (!branch || branch->type != OBJ_COMMIT)
 353                 return;
 354
 355         setup_revisions(0, NULL, rev, NULL);
 356         add_pending_object(rev, branch, name);
 357         add_pending_object(rev, &head->object, "^HEAD");
 358         head->object.flags |= UNINTERESTING;
 359         if (prepare_revision_walk(rev))
 360                 die("revision walk setup failed");
 361         while ((commit = get_revision(rev)) != NULL) {
 362                 struct pretty_print_context ctx = {0};
 363
 364                 if (commit->parents && commit->parents->next) {
 365                         /* do not list a merge but count committer */
 366                         if (opts->credit_people)
 367                                 record_person('c', &committers, commit);
 368                         continue;
 369                 }
 370                 if (!count && opts->credit_people)
 371                         /* the 'tip' committer */
 372                         record_person('c', &committers, commit);
 373                 if (opts->credit_people)
 374                         record_person('a', &authors, commit);
 375                 count++;
 376                 if (subjects.nr > limit)
 377                         continue;
 378
 379                 format_commit_message(commit, "%s", &sb, &ctx);
 380                 strbuf_ltrim(&sb);
 381
 382                 if (!sb.len)
 383                         string_list_append(&subjects,
 384                                            oid_to_hex(&commit->object.oid));
 385                 else
 386                         string_list_append_nodup(&subjects,
 387                                                  strbuf_detach(&sb, NULL));
 388         }
 389
 390         if (opts->credit_people)
 391                 add_people_info(out, &authors, &committers);
 392         if (count > limit)
 393                 strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
 394         else
 395                 strbuf_addf(out, "\n* %s:\n", name);
 396
 397         if (origin_data->is_local_branch && use_branch_desc)
 398                 add_branch_desc(out, name);
 399
 400         for (i = 0; i < subjects.nr; i++)
 401                 if (i >= limit)
 402                         strbuf_addstr(out, "  ...\n");
 403                 else
 404                         strbuf_addf(out, "  %s\n", subjects.items[i].string);
 405
 406         clear_commit_marks((struct commit *)branch, flags);
 407         clear_commit_marks(head, flags);
 408         free_commit_list(rev->commits);
 409         rev->commits = NULL;
 410         rev->pending.nr = 0;
 411
 412         string_list_clear(&authors, 0);
 413         string_list_clear(&committers, 0);
 414         string_list_clear(&subjects, 0);
 415 }
 416
 417 static void fmt_merge_msg_title(struct strbuf *out,
 418                                 const char *current_branch)
 419 {
 420         int i = 0;
 421         char *sep = "";
 422
 423         strbuf_addstr(out, "Merge ");
 424         for (i = 0; i < srcs.nr; i++) {
 425                 struct src_data *src_data = srcs.items[i].util;
 426                 const char *subsep = "";
 427
 428                 strbuf_addstr(out, sep);
 429                 sep = "; ";
 430
 431                 if (src_data->head_status == 1) {
 432                         strbuf_addstr(out, srcs.items[i].string);
 433                         continue;
 434                 }
 435                 if (src_data->head_status == 3) {
 436                         subsep = ", ";
 437                         strbuf_addstr(out, "HEAD");
 438                 }
 439                 if (src_data->branch.nr) {
 440                         strbuf_addstr(out, subsep);
 441                         subsep = ", ";
 442                         print_joined("branch ", "branches ", &src_data->branch,
 443                                         out);
 444                 }
 445                 if (src_data->r_branch.nr) {
 446                         strbuf_addstr(out, subsep);
 447                         subsep = ", ";
 448                         print_joined("remote-tracking branch ", "remote-tracking branches ",
 449                                         &src_data->r_branch, out);
 450                 }
 451                 if (src_data->tag.nr) {
 452                         strbuf_addstr(out, subsep);
 453                         subsep = ", ";
 454                         print_joined("tag ", "tags ", &src_data->tag, out);
 455                 }
 456                 if (src_data->generic.nr) {
 457                         strbuf_addstr(out, subsep);
 458                         print_joined("commit ", "commits ", &src_data->generic,
 459                                         out);
 460                 }
 461                 if (strcmp(".", srcs.items[i].string))
 462                         strbuf_addf(out, " of %s", srcs.items[i].string);
 463         }
 464
 465         if (!strcmp("master", current_branch))
 466                 strbuf_addch(out, '\n');
 467         else
 468                 strbuf_addf(out, " into %s\n", current_branch);
 469 }
 470
 471 static void fmt_tag_signature(struct strbuf *tagbuf,
 472                               struct strbuf *sig,
 473                               const char *buf,
 474                               unsigned long len)
 475 {
 476         const char *tag_body = strstr(buf, "\n\n");
 477         if (tag_body) {
 478                 tag_body += 2;
 479                 strbuf_add(tagbuf, tag_body, buf + len - tag_body);
 480         }
 481         strbuf_complete_line(tagbuf);
 482         if (sig->len) {
 483                 strbuf_addch(tagbuf, '\n');
 484                 strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 485         }
 486 }
 487
 488 static void fmt_merge_msg_sigs(struct strbuf *out)
 489 {
 490         int i, tag_number = 0, first_tag = 0;
 491         struct strbuf tagbuf = STRBUF_INIT;
 492
 493         for (i = 0; i < origins.nr; i++) {
 494                 struct object_id *oid = origins.items[i].util;
 495                 enum object_type type;
 496                 unsigned long size, len;
 497                 char *buf = read_object_file(oid, &type, &size);
 498                 struct strbuf sig = STRBUF_INIT;
 499
 500                 if (!buf || type != OBJ_TAG)
 501                         goto next;
 502                 len = parse_signature(buf, size);
 503
 504                 if (size == len)
 505                         ; /* merely annotated */
 506                 else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
 507                         if (!sig.len)
 508                                 strbuf_addstr(&sig, "gpg verification failed.\n");
 509                 }
 510
 511                 if (!tag_number++) {
 512                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 513                         first_tag = i;
 514                 } else {
 515                         if (tag_number == 2) {
 516                                 struct strbuf tagline = STRBUF_INIT;
 517                                 strbuf_addch(&tagline, '\n');
 518                                 strbuf_add_commented_lines(&tagline,
 519                                                 origins.items[first_tag].string,
 520                                                 strlen(origins.items[first_tag].string));
 521                                 strbuf_insert(&tagbuf, 0, tagline.buf,
 522                                               tagline.len);
 523                                 strbuf_release(&tagline);
 524                         }
 525                         strbuf_addch(&tagbuf, '\n');
 526                         strbuf_add_commented_lines(&tagbuf,
 527                                         origins.items[i].string,
 528                                         strlen(origins.items[i].string));
 529                         fmt_tag_signature(&tagbuf, &sig, buf, len);
 530                 }
 531                 strbuf_release(&sig);
 532         next:
 533                 free(buf);
 534         }
 535         if (tagbuf.len) {
 536                 strbuf_addch(out, '\n');
 537                 strbuf_addbuf(out, &tagbuf);
 538         }
 539         strbuf_release(&tagbuf);
 540 }
 541
 542 static void find_merge_parents(struct merge_parents *result,
 543                                struct strbuf *in, struct object_id *head)
 544 {
 545         struct commit_list *parents;
 546         struct commit *head_commit;
 547         int pos = 0, i, j;
 548
 549         parents = NULL;
 550         while (pos < in->len) {
 551                 int len;
 552                 char *p = in->buf + pos;
 553                 char *newline = strchr(p, '\n');
 554                 const char *q;
 555                 struct object_id oid;
 556                 struct commit *parent;
 557                 struct object *obj;
 558
 559                 len = newline ? newline - p : strlen(p);
 560                 pos += len + !!newline;
 561
 562                 if (parse_oid_hex(p, &oid, &q) ||
 563                     q[0] != '\t' ||
 564                     q[1] != '\t')
 565                         continue; /* skip not-for-merge */
 566                 /*
 567                  * Do not use get_merge_parent() here; we do not have
 568                  * "name" here and we do not want to contaminate its
 569                  * util field yet.
 570                  */
 571                 obj = parse_object(the_repository, &oid);
 572                 parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 573                 if (!parent)
 574                         continue;
 575                 commit_list_insert(parent, &parents);
 576                 add_merge_parent(result, &obj->oid, &parent->object.oid);
 577         }
 578         head_commit = lookup_commit(the_repository, head);
 579         if (head_commit)
 580                 commit_list_insert(head_commit, &parents);
 581         reduce_heads_replace(&parents);
 582
 583         while (parents) {
 584                 struct commit *cmit = pop_commit(&parents);
 585                 for (i = 0; i < result->nr; i++)
 586                         if (oideq(&result->item[i].commit, &cmit->object.oid))
 587                                 result->item[i].used = 1;
 588         }
 589
 590         for (i = j = 0; i < result->nr; i++) {
 591                 if (result->item[i].used) {
 592                         if (i != j)
 593                                 result->item[j] = result->item[i];
 594                         j++;
 595                 }
 596         }
 597         result->nr = j;
 598 }
 599
 600 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 601                   struct fmt_merge_msg_opts *opts)
 602 {
 603         int i = 0, pos = 0;
 604         struct object_id head_oid;
 605         const char *current_branch;
 606         void *current_branch_to_free;
 607         struct merge_parents merge_parents;
 608
 609         memset(&merge_parents, 0, sizeof(merge_parents));
 610
 611         /* get current branch */
 612         current_branch = current_branch_to_free =
 613                 resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
 614         if (!current_branch)
 615                 die("No current branch");
 616         if (starts_with(current_branch, "refs/heads/"))
 617                 current_branch += 11;
 618
 619         find_merge_parents(&merge_parents, in, &head_oid);
 620
 621         /* get a line */
 622         while (pos < in->len) {
 623                 int len;
 624                 char *newline, *p = in->buf + pos;
 625
 626                 newline = strchr(p, '\n');
 627                 len = newline ? newline - p : strlen(p);
 628                 pos += len + !!newline;
 629                 i++;
 630                 p[len] = 0;
 631                 if (handle_line(p, &merge_parents))
 632                         die("error in line %d: %.*s", i, len, p);
 633         }
 634
 635         if (opts->add_title && srcs.nr)
 636                 fmt_merge_msg_title(out, current_branch);
 637
 638         if (origins.nr)
 639                 fmt_merge_msg_sigs(out);
 640
 641         if (opts->shortlog_len) {
 642                 struct commit *head;
 643                 struct rev_info rev;
 644
 645                 head = lookup_commit_or_die(&head_oid, "HEAD");
 646                 init_revisions(&rev, NULL);
 647                 rev.commit_format = CMIT_FMT_ONELINE;
 648                 rev.ignore_merges = 1;
 649                 rev.limited = 1;
 650
 651                 strbuf_complete_line(out);
 652
 653                 for (i = 0; i < origins.nr; i++)
 654                         shortlog(origins.items[i].string,
 655                                  origins.items[i].util,
 656                                  head, &rev, opts, out);
 657         }
 658
 659         strbuf_complete_line(out);
 660         free(current_branch_to_free);
 661         free(merge_parents.item);
 662         return 0;
 663 }
 664
 665 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 666 {
 667         const char *inpath = NULL;
 668         const char *message = NULL;
 669         int shortlog_len = -1;
 670         struct option options[] = {
 671                 { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
 672                   N_("populate log with at most <n> entries from shortlog"),
 673                   PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 674                 { OPTION_INTEGER, 0, "summary", &shortlog_len, N_("n"),
 675                   N_("alias for --log (deprecated)"),
 676                   PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
 677                   DEFAULT_MERGE_LOG_LEN },
 678                 OPT_STRING('m', "message", &message, N_("text"),
 679                         N_("use <text> as start of message")),
 680                 OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
 681                 OPT_END()
 682         };
 683
 684         FILE *in = stdin;
 685         struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
 686         int ret;
 687         struct fmt_merge_msg_opts opts;
 688
 689         git_config(fmt_merge_msg_config, NULL);
 690         argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
 691                              0);
 692         if (argc > 0)
 693                 usage_with_options(fmt_merge_msg_usage, options);
 694         if (shortlog_len < 0)
 695                 shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
 696
 697         if (inpath && strcmp(inpath, "-")) {
 698                 in = fopen(inpath, "r");
 699                 if (!in)
 700                         die_errno("cannot open '%s'", inpath);
 701         }
 702
 703         if (strbuf_read(&input, fileno(in), 0) < 0)
 704                 die_errno("could not read input file");
 705
 706         if (message)
 707                 strbuf_addstr(&output, message);
 708
 709         memset(&opts, 0, sizeof(opts));
 710         opts.add_title = !message;
 711         opts.credit_people = 1;
 712         opts.shortlog_len = shortlog_len;
 713
 714         ret = fmt_merge_msg(&input, &output, &opts);
 715         if (ret)
 716                 return ret;
 717         write_in_full(STDOUT_FILENO, output.buf, output.len);
 718         return 0;
 719 }