builtin / fmt-merge-msg.con commit config: write to $XDG_CONFIG_HOME/git/config file when appropriate (0e8593d)
   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        "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, *origin;
 104        struct src_data *src_data;
 105        struct string_list_item *item;
 106        int pulling_head = 0;
 107        unsigned char sha1[20];
 108
 109        if (len < 43 || line[40] != '\t')
 110                return 1;
 111
 112        if (!prefixcmp(line + 41, "not-for-merge"))
 113                return 0;
 114
 115        if (line[41] != '\t')
 116                return 2;
 117
 118        i = get_sha1_hex(line, sha1);
 119        if (i)
 120                return 3;
 121
 122        if (!find_merge_parent(merge_parents, sha1, NULL))
 123                return 0; /* subsumed by other parents */
 124
 125        origin_data = xcalloc(1, sizeof(struct origin_data));
 126        hashcpy(origin_data->sha1, sha1);
 127
 128        if (line[len - 1] == '\n')
 129                line[len - 1] = 0;
 130        line += 42;
 131
 132        /*
 133         * At this point, line points at the beginning of comment e.g.
 134         * "branch 'frotz' of git://that/repository.git".
 135         * Find the repository name and point it with src.
 136         */
 137        src = strstr(line, " of ");
 138        if (src) {
 139                *src = 0;
 140                src += 4;
 141                pulling_head = 0;
 142        } else {
 143                src = line;
 144                pulling_head = 1;
 145        }
 146
 147        item = unsorted_string_list_lookup(&srcs, src);
 148        if (!item) {
 149                item = string_list_append(&srcs, src);
 150                item->util = xcalloc(1, sizeof(struct src_data));
 151                init_src_data(item->util);
 152        }
 153        src_data = item->util;
 154
 155        if (pulling_head) {
 156                origin = src;
 157                src_data->head_status |= 1;
 158        } else if (!prefixcmp(line, "branch ")) {
 159                origin_data->is_local_branch = 1;
 160                origin = line + 7;
 161                string_list_append(&src_data->branch, origin);
 162                src_data->head_status |= 2;
 163        } else if (!prefixcmp(line, "tag ")) {
 164                origin = line;
 165                string_list_append(&src_data->tag, origin + 4);
 166                src_data->head_status |= 2;
 167        } else if (!prefixcmp(line, "remote-tracking branch ")) {
 168                origin = line + strlen("remote-tracking branch ");
 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                char *new_origin = xmalloc(strlen(origin) + strlen(src) + 5);
 183                sprintf(new_origin, "%s of %s", origin, src);
 184                origin = new_origin;
 185        }
 186        if (strcmp(".", src))
 187                origin_data->is_local_branch = 0;
 188        string_list_append(&origins, origin)->util = origin_data;
 189        return 0;
 190}
 191
 192static void print_joined(const char *singular, const char *plural,
 193                struct string_list *list, struct strbuf *out)
 194{
 195        if (list->nr == 0)
 196                return;
 197        if (list->nr == 1) {
 198                strbuf_addf(out, "%s%s", singular, list->items[0].string);
 199        } else {
 200                int i;
 201                strbuf_addstr(out, plural);
 202                for (i = 0; i < list->nr - 1; i++)
 203                        strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
 204                                    list->items[i].string);
 205                strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
 206        }
 207}
 208
 209static void add_branch_desc(struct strbuf *out, const char *name)
 210{
 211        struct strbuf desc = STRBUF_INIT;
 212
 213        if (!read_branch_desc(&desc, name)) {
 214                const char *bp = desc.buf;
 215                while (*bp) {
 216                        const char *ep = strchrnul(bp, '\n');
 217                        if (*ep)
 218                                ep++;
 219                        strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
 220                        bp = ep;
 221                }
 222                if (out->buf[out->len - 1] != '\n')
 223                        strbuf_addch(out, '\n');
 224        }
 225        strbuf_release(&desc);
 226}
 227
 228#define util_as_integral(elem) ((intptr_t)((elem)->util))
 229
 230static void record_person(int which, struct string_list *people,
 231                          struct commit *commit)
 232{
 233        char *name_buf, *name, *name_end;
 234        struct string_list_item *elem;
 235        const char *field = (which == 'a') ? "\nauthor " : "\ncommitter ";
 236
 237        name = strstr(commit->buffer, field);
 238        if (!name)
 239                return;
 240        name += strlen(field);
 241        name_end = strchrnul(name, '<');
 242        if (*name_end)
 243                name_end--;
 244        while (isspace(*name_end) && name <= name_end)
 245                name_end--;
 246        if (name_end < name)
 247                return;
 248        name_buf = xmemdupz(name, name_end - name + 1);
 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 = "\n# By ";
 290                me = git_author_info(IDENT_NO_DATE);
 291        } else {
 292                label = "\n# Via ";
 293                me = git_committer_info(IDENT_NO_DATE);
 294        }
 295
 296        if (!them->nr ||
 297            (them->nr == 1 &&
 298             me &&
 299             (me = skip_prefix(me, them->items->string)) != NULL &&
 300             skip_prefix(me, " <")))
 301                return;
 302        strbuf_addstr(out, 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, int limit,
 327                     struct strbuf *out)
 328{
 329        int i, count = 0;
 330        struct commit *commit;
 331        struct object *branch;
 332        struct string_list subjects = STRING_LIST_INIT_DUP;
 333        struct string_list authors = STRING_LIST_INIT_DUP;
 334        struct string_list committers = STRING_LIST_INIT_DUP;
 335        int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
 336        struct strbuf sb = STRBUF_INIT;
 337        const unsigned char *sha1 = origin_data->sha1;
 338
 339        branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
 340        if (!branch || branch->type != OBJ_COMMIT)
 341                return;
 342
 343        setup_revisions(0, NULL, rev, NULL);
 344        add_pending_object(rev, branch, name);
 345        add_pending_object(rev, &head->object, "^HEAD");
 346        head->object.flags |= UNINTERESTING;
 347        if (prepare_revision_walk(rev))
 348                die("revision walk setup failed");
 349        while ((commit = get_revision(rev)) != NULL) {
 350                struct pretty_print_context ctx = {0};
 351
 352                if (commit->parents && commit->parents->next) {
 353                        /* do not list a merge but count committer */
 354                        record_person('c', &committers, commit);
 355                        continue;
 356                }
 357                if (!count)
 358                        /* the 'tip' committer */
 359                        record_person('c', &committers, commit);
 360                record_person('a', &authors, commit);
 361                count++;
 362                if (subjects.nr > limit)
 363                        continue;
 364
 365                format_commit_message(commit, "%s", &sb, &ctx);
 366                strbuf_ltrim(&sb);
 367
 368                if (!sb.len)
 369                        string_list_append(&subjects,
 370                                           sha1_to_hex(commit->object.sha1));
 371                else
 372                        string_list_append(&subjects, strbuf_detach(&sb, NULL));
 373        }
 374
 375        add_people_info(out, &authors, &committers);
 376        if (count > limit)
 377                strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
 378        else
 379                strbuf_addf(out, "\n* %s:\n", name);
 380
 381        if (origin_data->is_local_branch && use_branch_desc)
 382                add_branch_desc(out, name);
 383
 384        for (i = 0; i < subjects.nr; i++)
 385                if (i >= limit)
 386                        strbuf_addf(out, "  ...\n");
 387                else
 388                        strbuf_addf(out, "  %s\n", subjects.items[i].string);
 389
 390        clear_commit_marks((struct commit *)branch, flags);
 391        clear_commit_marks(head, flags);
 392        free_commit_list(rev->commits);
 393        rev->commits = NULL;
 394        rev->pending.nr = 0;
 395
 396        string_list_clear(&authors, 0);
 397        string_list_clear(&committers, 0);
 398        string_list_clear(&subjects, 0);
 399}
 400
 401static void fmt_merge_msg_title(struct strbuf *out,
 402        const char *current_branch) {
 403        int i = 0;
 404        char *sep = "";
 405
 406        strbuf_addstr(out, "Merge ");
 407        for (i = 0; i < srcs.nr; i++) {
 408                struct src_data *src_data = srcs.items[i].util;
 409                const char *subsep = "";
 410
 411                strbuf_addstr(out, sep);
 412                sep = "; ";
 413
 414                if (src_data->head_status == 1) {
 415                        strbuf_addstr(out, srcs.items[i].string);
 416                        continue;
 417                }
 418                if (src_data->head_status == 3) {
 419                        subsep = ", ";
 420                        strbuf_addstr(out, "HEAD");
 421                }
 422                if (src_data->branch.nr) {
 423                        strbuf_addstr(out, subsep);
 424                        subsep = ", ";
 425                        print_joined("branch ", "branches ", &src_data->branch,
 426                                        out);
 427                }
 428                if (src_data->r_branch.nr) {
 429                        strbuf_addstr(out, subsep);
 430                        subsep = ", ";
 431                        print_joined("remote-tracking branch ", "remote-tracking branches ",
 432                                        &src_data->r_branch, out);
 433                }
 434                if (src_data->tag.nr) {
 435                        strbuf_addstr(out, subsep);
 436                        subsep = ", ";
 437                        print_joined("tag ", "tags ", &src_data->tag, out);
 438                }
 439                if (src_data->generic.nr) {
 440                        strbuf_addstr(out, subsep);
 441                        print_joined("commit ", "commits ", &src_data->generic,
 442                                        out);
 443                }
 444                if (strcmp(".", srcs.items[i].string))
 445                        strbuf_addf(out, " of %s", srcs.items[i].string);
 446        }
 447
 448        if (!strcmp("master", current_branch))
 449                strbuf_addch(out, '\n');
 450        else
 451                strbuf_addf(out, " into %s\n", current_branch);
 452}
 453
 454static void fmt_tag_signature(struct strbuf *tagbuf,
 455                              struct strbuf *sig,
 456                              const char *buf,
 457                              unsigned long len)
 458{
 459        const char *tag_body = strstr(buf, "\n\n");
 460        if (tag_body) {
 461                tag_body += 2;
 462                strbuf_add(tagbuf, tag_body, buf + len - tag_body);
 463        }
 464        strbuf_complete_line(tagbuf);
 465        if (sig->len) {
 466                strbuf_addch(tagbuf, '\n');
 467                strbuf_add_lines(tagbuf, "# ", sig->buf, sig->len);
 468        }
 469}
 470
 471static void fmt_merge_msg_sigs(struct strbuf *out)
 472{
 473        int i, tag_number = 0, first_tag = 0;
 474        struct strbuf tagbuf = STRBUF_INIT;
 475
 476        for (i = 0; i < origins.nr; i++) {
 477                unsigned char *sha1 = origins.items[i].util;
 478                enum object_type type;
 479                unsigned long size, len;
 480                char *buf = read_sha1_file(sha1, &type, &size);
 481                struct strbuf sig = STRBUF_INIT;
 482
 483                if (!buf || type != OBJ_TAG)
 484                        goto next;
 485                len = parse_signature(buf, size);
 486
 487                if (size == len)
 488                        ; /* merely annotated */
 489                else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig)) {
 490                        if (!sig.len)
 491                                strbuf_addstr(&sig, "gpg verification failed.\n");
 492                }
 493
 494                if (!tag_number++) {
 495                        fmt_tag_signature(&tagbuf, &sig, buf, len);
 496                        first_tag = i;
 497                } else {
 498                        if (tag_number == 2) {
 499                                struct strbuf tagline = STRBUF_INIT;
 500                                strbuf_addf(&tagline, "\n# %s\n",
 501                                            origins.items[first_tag].string);
 502                                strbuf_insert(&tagbuf, 0, tagline.buf,
 503                                              tagline.len);
 504                                strbuf_release(&tagline);
 505                        }
 506                        strbuf_addf(&tagbuf, "\n# %s\n",
 507                                    origins.items[i].string);
 508                        fmt_tag_signature(&tagbuf, &sig, buf, len);
 509                }
 510                strbuf_release(&sig);
 511        next:
 512                free(buf);
 513        }
 514        if (tagbuf.len) {
 515                strbuf_addch(out, '\n');
 516                strbuf_addbuf(out, &tagbuf);
 517        }
 518        strbuf_release(&tagbuf);
 519}
 520
 521static void find_merge_parents(struct merge_parents *result,
 522                               struct strbuf *in, unsigned char *head)
 523{
 524        struct commit_list *parents, *next;
 525        struct commit *head_commit;
 526        int pos = 0, i, j;
 527
 528        parents = NULL;
 529        while (pos < in->len) {
 530                int len;
 531                char *p = in->buf + pos;
 532                char *newline = strchr(p, '\n');
 533                unsigned char sha1[20];
 534                struct commit *parent;
 535                struct object *obj;
 536
 537                len = newline ? newline - p : strlen(p);
 538                pos += len + !!newline;
 539
 540                if (len < 43 ||
 541                    get_sha1_hex(p, sha1) ||
 542                    p[40] != '\t' ||
 543                    p[41] != '\t')
 544                        continue; /* skip not-for-merge */
 545                /*
 546                 * Do not use get_merge_parent() here; we do not have
 547                 * "name" here and we do not want to contaminate its
 548                 * util field yet.
 549                 */
 550                obj = parse_object(sha1);
 551                parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
 552                if (!parent)
 553                        continue;
 554                commit_list_insert(parent, &parents);
 555                add_merge_parent(result, obj->sha1, parent->object.sha1);
 556        }
 557        head_commit = lookup_commit(head);
 558        if (head_commit)
 559                commit_list_insert(head_commit, &parents);
 560        parents = reduce_heads(parents);
 561
 562        while (parents) {
 563                for (i = 0; i < result->nr; i++)
 564                        if (!hashcmp(result->item[i].commit,
 565                                     parents->item->object.sha1))
 566                                result->item[i].used = 1;
 567                next = parents->next;
 568                free(parents);
 569                parents = next;
 570        }
 571
 572        for (i = j = 0; i < result->nr; i++) {
 573                if (result->item[i].used) {
 574                        if (i != j)
 575                                result->item[j] = result->item[i];
 576                        j++;
 577                }
 578        }
 579        result->nr = j;
 580}
 581
 582int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 583                  struct fmt_merge_msg_opts *opts)
 584{
 585        int i = 0, pos = 0;
 586        unsigned char head_sha1[20];
 587        const char *current_branch;
 588        void *current_branch_to_free;
 589        struct merge_parents merge_parents;
 590
 591        memset(&merge_parents, 0, sizeof(merge_parents));
 592
 593        /* get current branch */
 594        current_branch = current_branch_to_free =
 595                resolve_refdup("HEAD", head_sha1, 1, NULL);
 596        if (!current_branch)
 597                die("No current branch");
 598        if (!prefixcmp(current_branch, "refs/heads/"))
 599                current_branch += 11;
 600
 601        find_merge_parents(&merge_parents, in, head_sha1);
 602
 603        /* get a line */
 604        while (pos < in->len) {
 605                int len;
 606                char *newline, *p = in->buf + pos;
 607
 608                newline = strchr(p, '\n');
 609                len = newline ? newline - p : strlen(p);
 610                pos += len + !!newline;
 611                i++;
 612                p[len] = 0;
 613                if (handle_line(p, &merge_parents))
 614                        die ("Error in line %d: %.*s", i, len, p);
 615        }
 616
 617        if (opts->add_title && srcs.nr)
 618                fmt_merge_msg_title(out, current_branch);
 619
 620        if (origins.nr)
 621                fmt_merge_msg_sigs(out);
 622
 623        if (opts->shortlog_len) {
 624                struct commit *head;
 625                struct rev_info rev;
 626
 627                head = lookup_commit_or_die(head_sha1, "HEAD");
 628                init_revisions(&rev, NULL);
 629                rev.commit_format = CMIT_FMT_ONELINE;
 630                rev.ignore_merges = 1;
 631                rev.limited = 1;
 632
 633                strbuf_complete_line(out);
 634
 635                for (i = 0; i < origins.nr; i++)
 636                        shortlog(origins.items[i].string,
 637                                 origins.items[i].util,
 638                                 head, &rev, opts->shortlog_len, out);
 639        }
 640
 641        strbuf_complete_line(out);
 642        free(current_branch_to_free);
 643        free(merge_parents.item);
 644        return 0;
 645}
 646
 647int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 648{
 649        const char *inpath = NULL;
 650        const char *message = NULL;
 651        int shortlog_len = -1;
 652        struct option options[] = {
 653                { OPTION_INTEGER, 0, "log", &shortlog_len, "n",
 654                  "populate log with at most <n> entries from shortlog",
 655                  PARSE_OPT_OPTARG, NULL, DEFAULT_MERGE_LOG_LEN },
 656                { OPTION_INTEGER, 0, "summary", &shortlog_len, "n",
 657                  "alias for --log (deprecated)",
 658                  PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, NULL,
 659                  DEFAULT_MERGE_LOG_LEN },
 660                OPT_STRING('m', "message", &message, "text",
 661                        "use <text> as start of message"),
 662                OPT_FILENAME('F', "file", &inpath, "file to read from"),
 663                OPT_END()
 664        };
 665
 666        FILE *in = stdin;
 667        struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
 668        int ret;
 669        struct fmt_merge_msg_opts opts;
 670
 671        git_config(fmt_merge_msg_config, NULL);
 672        argc = parse_options(argc, argv, prefix, options, fmt_merge_msg_usage,
 673                             0);
 674        if (argc > 0)
 675                usage_with_options(fmt_merge_msg_usage, options);
 676        if (shortlog_len < 0)
 677                shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
 678
 679        if (inpath && strcmp(inpath, "-")) {
 680                in = fopen(inpath, "r");
 681                if (!in)
 682                        die_errno("cannot open '%s'", inpath);
 683        }
 684
 685        if (strbuf_read(&input, fileno(in), 0) < 0)
 686                die_errno("could not read input file");
 687
 688        if (message)
 689                strbuf_addstr(&output, message);
 690
 691        memset(&opts, 0, sizeof(opts));
 692        opts.add_title = !message;
 693        opts.shortlog_len = shortlog_len;
 694
 695        ret = fmt_merge_msg(&input, &output, &opts);
 696        if (ret)
 697                return ret;
 698        write_in_full(STDOUT_FILENO, output.buf, output.len);
 699        return 0;
 700}