Andrew's git / gitweb.git / builtin/fmt-merge-msg.c
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builtin / fmt-merge-msg.con commit Merge branch 'tb/connect-ipv6-parse-fix' (42da484)
   1#include "builtin.h"
   2#include "cache.h"
   3#include "commit.h"
   4#include "diff.h"
   5#include "revision.h"
   6#include "tag.h"
   7#include "string-list.h"
   8#include "branch.h"
   9#include "fmt-merge-msg.h"
  10#include "gpg-interface.h"
  11
  12static const char * const fmt_merge_msg_usage[] = {
  13        N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
  14        NULL
  15};
  16
  17static int use_branch_desc;
  18
  19int fmt_merge_msg_config(const char *key, const char *value, void *cb)
  20{
  21        if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
  22                int is_bool;
  23                merge_log_config = git_config_bool_or_int(key, value, &is_bool);
  24                if (!is_bool && merge_log_config < 0)
  25                        return error("%s: negative length %s", key, value);
  26                if (is_bool && merge_log_config)
  27                        merge_log_config = DEFAULT_MERGE_LOG_LEN;
  28        } else if (!strcmp(key, "merge.branchdesc")) {
  29                use_branch_desc = git_config_bool(key, value);
  30        } else {
  31                return git_default_config(key, value, cb);
  32        }
  33        return 0;
  34}
  35
  36/* merge data per repository where the merged tips came from */
  37struct src_data {
  38        struct string_list branch, tag, r_branch, generic;
  39        int head_status;
  40};
  41
  42struct origin_data {
  43        unsigned char sha1[20];
  44        unsigned is_local_branch:1;
  45};
  46
  47static void init_src_data(struct src_data *data)
  48{
  49        data->branch.strdup_strings = 1;
  50        data->tag.strdup_strings = 1;
  51        data->r_branch.strdup_strings = 1;
  52        data->generic.strdup_strings = 1;
  53}
  54
  55static struct string_list srcs = STRING_LIST_INIT_DUP;
  56static struct string_list origins = STRING_LIST_INIT_DUP;
  57
  58struct merge_parents {
  59        int alloc, nr;
  60        struct merge_parent {
  61                unsigned char given[20];
  62                unsigned char commit[20];
  63                unsigned char used;
  64        } *item;
  65};
  66
  67/*
  68 * I know, I know, this is inefficient, but you won't be pulling and merging
  69 * hundreds of heads at a time anyway.
  70 */
  71static struct merge_parent *find_merge_parent(struct merge_parents *table,
  72                                              unsigned char *given,
  73                                              unsigned char *commit)
  74{
  75        int i;
  76        for (i = 0; i < table->nr; i++) {
  77                if (given && hashcmp(table->item[i].given, given))
  78                        continue;
  79                if (commit && hashcmp(table->item[i].commit, commit))
  80                        continue;
  81                return &table->item[i];
  82        }
  83        return NULL;
  84}
  85
  86static void add_merge_parent(struct merge_parents *table,
  87                             unsigned char *given,
  88                             unsigned char *commit)
  89{
  90        if (table->nr && find_merge_parent(table, given, commit))
  91                return;
  92        ALLOC_GROW(table->item, table->nr + 1, table->alloc);
  93        hashcpy(table->item[table->nr].given, given);
  94        hashcpy(table->item[table->nr].commit, commit);
  95        table->item[table->nr].used = 0;
  96        table->nr++;
  97}
  98
  99static int handle_line(char *line, struct merge_parents *merge_parents)
 100{
 101        int i, len = strlen(line);
 102        struct origin_data *origin_data;
 103        char *src;
 104        const char *origin;
 105        struct src_data *src_data;
 106        struct string_list_item *item;
 107        int pulling_head = 0;
 108        unsigned char sha1[20];
 109
 110        if (len < 43 || line[40] != '\t')
 111                return 1;
 112
 113        if (starts_with(line + 41, "not-for-merge"))
 114                return 0;
 115
 116        if (line[41] != '\t')
 117                return 2;
 118
 119        i = get_sha1_hex(line, sha1);
 120        if (i)
 121                return 3;
 122
 123        if (!find_merge_parent(merge_parents, sha1, NULL))
 124                return 0; /* subsumed by other parents */
 125
 126        origin_data = xcalloc(1, sizeof(struct origin_data));
 127        hashcpy(origin_data->sha1, sha1);
 128
 129        if (line[len - 1] == '\n')
 130                line[len - 1] = 0;
 131        line += 42;
 132
 133        /*
 134         * At this point, line points at the beginning of comment e.g.
 135         * "branch 'frotz' of git://that/repository.git".
 136         * Find the repository name and point it with src.
 137         */
 138        src = strstr(line, " of ");
 139        if (src) {
 140                *src = 0;
 141                src += 4;
 142                pulling_head = 0;
 143        } else {
 144                src = line;
 145                pulling_head = 1;
 146        }
 147
 148        item = unsorted_string_list_lookup(&srcs, src);
 149        if (!item) {
 150                item = string_list_append(&srcs, src);
 151                item->util = xcalloc(1, sizeof(struct src_data));
 152                init_src_data(item->util);
 153        }
 154        src_data = item->util;
 155
 156        if (pulling_head) {
 157                origin = src;
 158                src_data->head_status |= 1;
 159        } else if (starts_with(line, "branch ")) {
 160                origin_data->is_local_branch = 1;
 161                origin = line + 7;
 162                string_list_append(&src_data->branch, origin);
 163                src_data->head_status |= 2;
 164        } else if (starts_with(line, "tag ")) {
 165                origin = line;
 166                string_list_append(&src_data->tag, origin + 4);
 167                src_data->head_status |= 2;
 168        } else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
 169                string_list_append(&src_data->r_branch, origin);
 170                src_data->head_status |= 2;
 171        } else {
 172                origin = src;
 173                string_list_append(&src_data->generic, line);
 174                src_data->head_status |= 2;
 175        }
 176
 177        if (!strcmp(".", src) || !strcmp(src, origin)) {
 178                int len = strlen(origin);
 179                if (origin[0] == '\'' && origin[len - 1] == '\'')
 180                        origin = xmemdupz(origin + 1, len - 2);
 181        } else
 182                origin = xstrfmt("%s of %s", origin, src);
 183        if (strcmp(".", src))
 184                origin_data->is_local_branch = 0;
 185        string_list_append(&origins, origin)->util = origin_data;
 186        return 0;
 187}
 188
 189static void print_joined(const char *singular, const char *plural,
 190                struct string_list *list, struct strbuf *out)
 191{
 192        if (list->nr == 0)
 193                return;
 194        if (list->nr == 1) {
 195                strbuf_addf(out, "%s%s", singular, list->items[0].string);
 196        } else {
 197                int i;
 198                strbuf_addstr(out, plural);
 199                for (i = 0; i < list->nr - 1; i++)
 200                        strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
 201                                    list->items[i].string);
 202                strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
 203        }
 204}
 205
 206static void add_branch_desc(struct strbuf *out, const char *name)
 207{
 208        struct strbuf desc = STRBUF_INIT;
 209
 210        if (!read_branch_desc(&desc, name)) {
 211                const char *bp = desc.buf;
 212                while (*bp) {
 213                        const char *ep = strchrnul(bp, '\n');
 214                        if (*ep)
 215                                ep++;
 216                        strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
 217                        bp = ep;
 218                }
 219                strbuf_complete_line(out);
 220        }
 221        strbuf_release(&desc);
 222}
 223
 224#define util_as_integral(elem) ((intptr_t)((elem)->util))
 225
 226static void record_person(int which, struct string_list *people,
 227                          struct commit *commit)
 228{
 229        const char *buffer;
 230        char *name_buf, *name, *name_end;
 231        struct string_list_item *elem;
 232        const char *field;
 233
 234        field = (which == 'a') ? "\nauthor " : "\ncommitter ";
 235        buffer = get_commit_buffer(commit, NULL);
 236        name = strstr(buffer, field);
 237        if (!name)
 238                return;
 239        name += strlen(field);
 240        name_end = strchrnul(name, '<');
 241        if (*name_end)
 242                name_end--;
 243        while (isspace(*name_end) && name <= name_end)
 244                name_end--;
 245        if (name_end < name)
 246                return;
 247        name_buf = xmemdupz(name, name_end - name + 1);
 248        unuse_commit_buffer(commit, buffer);
 249
 250        elem = string_list_lookup(people, name_buf);
 251        if (!elem) {
 252                elem = string_list_insert(people, name_buf);
 253                elem->util = (void *)0;
 254        }
 255        elem->util = (void*)(util_as_integral(elem) + 1);
 256        free(name_buf);
 257}
 258
 259static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
 260{
 261        const struct string_list_item *a = a_, *b = b_;
 262        return util_as_integral(b) - util_as_integral(a);
 263}
 264
 265static void add_people_count(struct strbuf *out, struct string_list *people)
 266{
 267        if (people->nr == 1)
 268                strbuf_addf(out, "%s", people->items[0].string);
 269        else if (people->nr == 2)
 270                strbuf_addf(out, "%s (%d) and %s (%d)",
 271                            people->items[0].string,
 272                            (int)util_as_integral(&people->items[0]),
 273                            people->items[1].string,
 274                            (int)util_as_integral(&people->items[1]));
 275        else if (people->nr)
 276                strbuf_addf(out, "%s (%d) and others",
 277                            people->items[0].string,
 278                            (int)util_as_integral(&people->items[0]));
 279}
 280
 281static void credit_people(struct strbuf *out,
 282                          struct string_list *them,
 283                          int kind)
 284{
 285        const char *label;
 286        const char *me;
 287
 288        if (kind == 'a') {
 289                label = "By";
 290                me = git_author_info(IDENT_NO_DATE);
 291        } else {
 292                label = "Via";
 293                me = git_committer_info(IDENT_NO_DATE);
 294        }
 295
 296        if (!them->nr ||
 297            (them->nr == 1 &&
 298             me &&
 299             skip_prefix(me, them->items->string, &me) &&
 300             starts_with(me, " <")))
 301                return;
 302        strbuf_addf(out, "\n%c %s ", comment_line_char, label);
 303        add_people_count(out, them);
 304}
 305
 306static void add_people_info(struct strbuf *out,
 307                            struct string_list *authors,
 308                            struct string_list *committers)
 309{
 310        if (authors->nr)
 311                qsort(authors->items,
 312                      authors->nr, sizeof(authors->items[0]),
 313                      cmp_string_list_util_as_integral);
 314        if (committers->nr)
 315                qsort(committers->items,
 316                      committers->nr, sizeof(committers->items[0]),
 317                      cmp_string_list_util_as_integral);
 318
 319        credit_people(out, authors, 'a');
 320        credit_people(out, committers, 'c');
 321}
 322
 323static void shortlog(const char *name,
 324                     struct origin_data *origin_data,
 325                     struct commit *head,
 326                     struct rev_info *rev,
 327                     struct fmt_merge_msg_opts *opts,
 328                     struct strbuf *out)
 329{
 330        int i, count = 0;
 331        struct commit *commit;
 332        struct object *branch;
 333        struct string_list subjects = STRING_LIST_INIT_DUP;
 334        struct string_list authors = STRING_LIST_INIT_DUP;
 335        struct string_list committers = STRING_LIST_INIT_DUP;
 336        int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 337        struct strbuf sb = STRBUF_INIT;
 338        const unsigned char *sha1 = origin_data->sha1;
 339        int limit = opts->shortlog_len;
 340
 341        branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
 342        if (!branch || branch->type != OBJ_COMMIT)
 343                return;
 344
 345        setup_revisions(0, NULL, rev, NULL);
 346        add_pending_object(rev, branch, name);
 347        add_pending_object(rev, &head->object, "^HEAD");
 348        head->object.flags |= UNINTERESTING;
 349        if (prepare_revision_walk(rev))
 350                die("revision walk setup failed");
 351        while ((commit = get_revision(rev)) != NULL) {
 352                struct pretty_print_context ctx = {0};
 353
 354                if (commit->parents && commit->parents->next) {
 355                        /* do not list a merge but count committer */
 356                        if (opts->credit_people)
 357                                record_person('c', &committers, commit);
 358                        continue;
 359                }
 360                if (!count && opts->credit_people)
 361                        /* the 'tip' committer */
 362                        record_person('c', &committers, commit);
 363                if (opts->credit_people)
 364                        record_person('a', &authors, commit);
 365                count++;
 366                if (subjects.nr > limit)
 367                        continue;
 368
 369                format_commit_message(commit, "%s", &sb, &ctx);
 370                strbuf_ltrim(&sb);
 371
 372                if (!sb.len)
 373                        string_list_append(&subjects,
 374                                           sha1_to_hex(commit->object.sha1));
 375                else
 376                        string_list_append(&subjects, strbuf_detach(&sb, NULL));
 377        }
 378
 379        if (opts->credit_people)
 380                add_people_info(out, &authors, &committers);
 381        if (count > limit)
 382                strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
 383        else
 384                strbuf_addf(out, "\n* %s:\n", name);
 385
 386        if (origin_data->is_local_branch && use_branch_desc)
 387                add_branch_desc(out, name);
 388
 389        for (i = 0; i < subjects.nr; i++)
 390                if (i >= limit)
 391                        strbuf_addf(out, "  ...\n");
 392                else
 393                        strbuf_addf(out, "  %s\n", subjects.items[i].string);
 394
 395        clear_commit_marks((struct commit *)branch, flags);
 396        clear_commit_marks(head, flags);
 397        free_commit_list(rev->commits);
 398        rev->commits = NULL;
 399        rev->pending.nr = 0;
 400
 401        string_list_clear(&authors, 0);
 402        string_list_clear(&committers, 0);
 403        string_list_clear(&subjects, 0);
 404}
 405
 406static void fmt_merge_msg_title(struct strbuf *out,
 407        const char *current_branch) {
 408        int i = 0;
 409        char *sep = "";
 410
 411        strbuf_addstr(out, "Merge ");
 412        for (i = 0; i < srcs.nr; i++) {
 413                struct src_data *src_data = srcs.items[i].util;
 414                const char *subsep = "";
 415
 416                strbuf_addstr(out, sep);
 417                sep = "; ";
 418
 419                if (src_data->head_status == 1) {
 420                        strbuf_addstr(out, srcs.items[i].string);
 421                        continue;
 422                }
 423                if (src_data->head_status == 3) {
 424                        subsep = ", ";
 425                        strbuf_addstr(out, "HEAD");
 426                }
 427                if (src_data->branch.nr) {
 428                        strbuf_addstr(out, subsep);
 429                        subsep = ", ";
 430                        print_joined("branch ", "branches ", &src_data->branch,
 431                                        out);
 432                }
 433                if (src_data->r_branch.nr) {
 434                        strbuf_addstr(out, subsep);
 435                        subsep = ", ";
 436                        print_joined("remote-tracking branch ", "remote-tracking branches ",
 437                                        &src_data->r_branch, out);
 438                }
 439                if (src_data->tag.nr) {
 440                        strbuf_addstr(out, subsep);
 441                        subsep = ", ";
 442                        print_joined("tag ", "tags ", &src_data->tag, out);
 443                }
 444                if (src_data->generic.nr) {
 445                        strbuf_addstr(out, subsep);
 446                        print_joined("commit ", "commits ", &src_data->generic,
 447                                        out);
 448                }
 449                if (strcmp(".", srcs.items[i].string))
 450                        strbuf_addf(out, " of %s", srcs.items[i].string);
 451        }
 452
 453        if (!strcmp("master", current_branch))
 454                strbuf_addch(out, '\n');
 455        else
 456                strbuf_addf(out, " into %s\n", current_branch);
 457}
 458
 459static void fmt_tag_signature(struct strbuf *tagbuf,
 460                              struct strbuf *sig,
 461                              const char *buf,
 462                              unsigned long len)
 463{
 464        const char *tag_body = strstr(buf, "\n\n");
 465        if (tag_body) {
 466                tag_body += 2;
 467                strbuf_add(tagbuf, tag_body, buf + len - tag_body);
 468        }
 469        strbuf_complete_line(tagbuf);
 470        if (sig->len) {
 471                strbuf_addch(tagbuf, '\n');
 472                strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
 473        }
 474}
 475
 476static void fmt_merge_msg_sigs(struct strbuf *out)
 477{
 478        int i, tag_number = 0, first_tag = 0;
 479        struct strbuf tagbuf = STRBUF_INIT;
 480
 481        for (i = 0; i < origins.nr; i++) {
 482                unsigned char *sha1 = origins.items[i].util;
 483                enum object_type type;
 484                unsigned long size, len;
 485                char *buf = read_sha1_file(sha1, &type, &size);
 486                struct strbuf sig = STRBUF_INIT;
 487
 488                if (!buf || type != OBJ_TAG)
 489                        goto next;
 490                len = parse_signature(buf, size);
 491
 492                if (size == len)
 493                        ; /* merely annotated */
 494                else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
 495                        if (!sig.len)
 496                                strbuf_addstr(&sig, "gpg verification failed.\n");
 497                }
 498
 499                if (!tag_number++) {
 500                        fmt_tag_signature(&tagbuf, &sig, buf, len);
 501                        first_tag = i;
 502                } else {
 503                        if (tag_number == 2) {
 504                                struct strbuf tagline = STRBUF_INIT;
 505                                strbuf_addch(&tagline, '\n');
 506                                strbuf_add_commented_lines(&tagline,
 507                                                origins.items[first_tag].string,
 508                                                strlen(origins.items[first_tag].string));
 509                                strbuf_insert(&tagbuf, 0, tagline.buf,
 510                                              tagline.len);
 511                                strbuf_release(&tagline);
 512                        }
 513                        strbuf_addch(&tagbuf, '\n');
 514                        strbuf_add_commented_lines(&tagbuf,
 515                                        origins.items[i].string,
 516                                        strlen(origins.items[i].string));
 517                        fmt_tag_signature(&tagbuf, &sig, buf, len);
 518                }
 519                strbuf_release(&sig);
 520        next:
 521                free(buf);
 522        }
 523        if (tagbuf.len) {
 524                strbuf_addch(out, '\n');
 525                strbuf_addbuf(out, &tagbuf);
 526        }
 527        strbuf_release(&tagbuf);
 528}
 529
 530static void find_merge_parents(struct merge_parents *result,
 531                               struct strbuf *in, unsigned char *head)
 532{
 533        struct commit_list *parents, *next;
 534        struct commit *head_commit;
 535        int pos = 0, i, j;
 536
 537        parents = NULL;
 538        while (pos < in->len) {
 539                int len;
 540                char *p = in->buf + pos;
 541                char *newline = strchr(p, '\n');
 542                unsigned char sha1[20];
 543                struct commit *parent;
 544                struct object *obj;
 545
 546                len = newline ? newline - p : strlen(p);
 547                pos += len + !!newline;
 548
 549                if (len < 43 ||
 550                    get_sha1_hex(p, sha1) ||
 551                    p[40] != '\t' ||
 552                    p[41] != '\t')
 553                        continue; /* skip not-for-merge */
 554                /*
 555                 * Do not use get_merge_parent() here; we do not have
 556                 * "name" here and we do not want to contaminate its
 557                 * util field yet.
 558                 */
 559                obj = parse_object(sha1);
 560                parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 561                if (!parent)
 562                        continue;
 563                commit_list_insert(parent, &parents);
 564                add_merge_parent(result, obj->sha1, parent->object.sha1);
 565        }
 566        head_commit = lookup_commit(head);
 567        if (head_commit)
 568                commit_list_insert(head_commit, &parents);
 569        parents = reduce_heads(parents);
 570
 571        while (parents) {
 572                for (i = 0; i < result->nr; i++)
 573                        if (!hashcmp(result->item[i].commit,
 574                                     parents->item->object.sha1))
 575                                result->item[i].used = 1;
 576                next = parents->next;
 577                free(parents);
 578                parents = next;
 579        }
 580
 581        for (i = j = 0; i < result->nr; i++) {
 582                if (result->item[i].used) {
 583                        if (i != j)
 584                                result->item[j] = result->item[i];
 585                        j++;
 586                }
 587        }
 588        result->nr = j;
 589}
 590
 591int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 592                  struct fmt_merge_msg_opts *opts)
 593{
 594        int i = 0, pos = 0;
 595        unsigned char head_sha1[20];
 596        const char *current_branch;
 597        void *current_branch_to_free;
 598        struct merge_parents merge_parents;
 599
 600        memset(&merge_parents, 0, sizeof(merge_parents));
 601
 602        /* get current branch */
 603        current_branch = current_branch_to_free =
 604                resolve_refdup("HEAD", RESOLVE_REF_READING, head_sha1, NULL);
 605        if (!current_branch)
 606                die("No current branch");
 607        if (starts_with(current_branch, "refs/heads/"))
 608                current_branch += 11;
 609
 610        find_merge_parents(&merge_parents, in, head_sha1);
 611
 612        /* get a line */
 613        while (pos < in->len) {
 614                int len;
 615                char *newline, *p = in->buf + pos;
 616
 617                newline = strchr(p, '\n');
 618                len = newline ? newline - p : strlen(p);
 619                pos += len + !!newline;
 620                i++;
 621                p[len] = 0;
 622                if (handle_line(p, &merge_parents))
 623                        die ("Error in line %d: %.*s", i, len, p);
 624        }
 625
 626        if (opts->add_title && srcs.nr)
 627                fmt_merge_msg_title(out, current_branch);
 628
 629        if (origins.nr)
 630                fmt_merge_msg_sigs(out);
 631
 632        if (opts->shortlog_len) {
 633                struct commit *head;
 634                struct rev_info rev;
 635
 636                head = lookup_commit_or_die(head_sha1, "HEAD");
 637                init_revisions(&rev, NULL);
 638                rev.commit_format = CMIT_FMT_ONELINE;
 639                rev.ignore_merges = 1;
 640                rev.limited = 1;
 641
 642                strbuf_complete_line(out);
 643
 644                for (i = 0; i < origins.nr; i++)
 645                        shortlog(origins.items[i].string,
 646                                 origins.items[i].util,
 647                                 head, &rev, opts, out);
 648        }
 649
 650        strbuf_complete_line(out);
 651        free(current_branch_to_free);
 652        free(merge_parents.item);
 653        return 0;
 654}
 655
 656int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 657{
 658        const char *inpath = NULL;
 659        const char *message = NULL;
 660        int shortlog_len = -1;
 661        struct option options[] = {
 662                { OPTION_INTEGER, 0, "log", &shortlog_len, N_("n"),
 663                  N_("populate log with at most <n> entries from shortlog"),
 664                  PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 665                { OPTION_INTEGER, 0, "summary", &shortlog_len, N_("n"),
 666                  N_("alias for --log (deprecated)"),
 667                  PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
 668                  DEFAULT_MERGE_LOG_LEN },
 669                OPT_STRING('m', "message", &message, N_("text"),
 670                        N_("use <text> as start of message")),
 671                OPT_FILENAME('F', "file", &inpath, N_("file to read from")),
 672                OPT_END()
 673        };
 674
 675        FILE *in = stdin;
 676        struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
 677        int ret;
 678        struct fmt_merge_msg_opts opts;
 679
 680        git_config(fmt_merge_msg_config, NULL);
 681        argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
 682                             0);
 683        if (argc > 0)
 684                usage_with_options(fmt_merge_msg_usage, options);
 685        if (shortlog_len < 0)
 686                shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
 687
 688        if (inpath && strcmp(inpath, "-")) {
 689                in = fopen(inpath, "r");
 690                if (!in)
 691                        die_errno("cannot open '%s'", inpath);
 692        }
 693
 694        if (strbuf_read(&input, fileno(in), 0) < 0)
 695                die_errno("could not read input file");
 696
 697        if (message)
 698                strbuf_addstr(&output, message);
 699
 700        memset(&opts, 0, sizeof(opts));
 701        opts.add_title = !message;
 702        opts.credit_people = 1;
 703        opts.shortlog_len = shortlog_len;
 704
 705        ret = fmt_merge_msg(&input, &output, &opts);
 706        if (ret)
 707                return ret;
 708        write_in_full(STDOUT_FILENO, output.buf, output.len);
 709        return 0;
 710}