Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "string-list.h"
   3#include "run-command.h"
   4#include "string-list.h"
   5#include "trailer.h"
   6/*
   7 * Copyright (c) 2013, 2014 Christian Couder <chriscool@tuxfamily.org>
   8 */
   9
  10enum action_where { WHERE_END, WHERE_AFTER, WHERE_BEFORE, WHERE_START };
  11enum action_if_exists { EXISTS_ADD_IF_DIFFERENT_NEIGHBOR, EXISTS_ADD_IF_DIFFERENT,
  12                        EXISTS_ADD, EXISTS_REPLACE, EXISTS_DO_NOTHING };
  13enum action_if_missing { MISSING_ADD, MISSING_DO_NOTHING };
  14
  15struct conf_info {
  16        char *name;
  17        char *key;
  18        char *command;
  19        enum action_where where;
  20        enum action_if_exists if_exists;
  21        enum action_if_missing if_missing;
  22};
  23
  24static struct conf_info default_conf_info;
  25
  26struct trailer_item {
  27        struct trailer_item *previous;
  28        struct trailer_item *next;
  29        const char *token;
  30        const char *value;
  31        struct conf_info conf;
  32};
  33
  34static struct trailer_item *first_conf_item;
  35
  36static char *separators = ":";
  37
  38#define TRAILER_ARG_STRING "$ARG"
  39
  40static int after_or_end(enum action_where where)
  41{
  42        return (where == WHERE_AFTER) || (where == WHERE_END);
  43}
  44
  45/*
  46 * Return the length of the string not including any final
  47 * punctuation. E.g., the input "Signed-off-by:" would return
  48 * 13, stripping the trailing punctuation but retaining
  49 * internal punctuation.
  50 */
  51static size_t token_len_without_separator(const char *token, size_t len)
  52{
  53        while (len > 0 && !isalnum(token[len - 1]))
  54                len--;
  55        return len;
  56}
  57
  58static int same_token(struct trailer_item *a, struct trailer_item *b)
  59{
  60        size_t a_len = token_len_without_separator(a->token, strlen(a->token));
  61        size_t b_len = token_len_without_separator(b->token, strlen(b->token));
  62        size_t min_len = (a_len > b_len) ? b_len : a_len;
  63
  64        return !strncasecmp(a->token, b->token, min_len);
  65}
  66
  67static int same_value(struct trailer_item *a, struct trailer_item *b)
  68{
  69        return !strcasecmp(a->value, b->value);
  70}
  71
  72static int same_trailer(struct trailer_item *a, struct trailer_item *b)
  73{
  74        return same_token(a, b) && same_value(a, b);
  75}
  76
  77static inline int contains_only_spaces(const char *str)
  78{
  79        const char *s = str;
  80        while (*s && isspace(*s))
  81                s++;
  82        return !*s;
  83}
  84
  85static inline void strbuf_replace(struct strbuf *sb, const char *a, const char *b)
  86{
  87        const char *ptr = strstr(sb->buf, a);
  88        if (ptr)
  89                strbuf_splice(sb, ptr - sb->buf, strlen(a), b, strlen(b));
  90}
  91
  92static void free_trailer_item(struct trailer_item *item)
  93{
  94        free(item->conf.name);
  95        free(item->conf.key);
  96        free(item->conf.command);
  97        free((char *)item->token);
  98        free((char *)item->value);
  99        free(item);
 100}
 101
 102static char last_non_space_char(const char *s)
 103{
 104        int i;
 105        for (i = strlen(s) - 1; i >= 0; i--)
 106                if (!isspace(s[i]))
 107                        return s[i];
 108        return '\0';
 109}
 110
 111static void print_tok_val(const char *tok, const char *val)
 112{
 113        char c = last_non_space_char(tok);
 114        if (!c)
 115                return;
 116        if (strchr(separators, c))
 117                printf("%s%s\n", tok, val);
 118        else
 119                printf("%s%c %s\n", tok, separators[0], val);
 120}
 121
 122static void print_all(struct trailer_item *first, int trim_empty)
 123{
 124        struct trailer_item *item;
 125        for (item = first; item; item = item->next) {
 126                if (!trim_empty || strlen(item->value) > 0)
 127                        print_tok_val(item->token, item->value);
 128        }
 129}
 130
 131static void update_last(struct trailer_item **last)
 132{
 133        if (*last)
 134                while ((*last)->next != NULL)
 135                        *last = (*last)->next;
 136}
 137
 138static void update_first(struct trailer_item **first)
 139{
 140        if (*first)
 141                while ((*first)->previous != NULL)
 142                        *first = (*first)->previous;
 143}
 144
 145static void add_arg_to_input_list(struct trailer_item *on_tok,
 146                                  struct trailer_item *arg_tok,
 147                                  struct trailer_item **first,
 148                                  struct trailer_item **last)
 149{
 150        if (after_or_end(arg_tok->conf.where)) {
 151                arg_tok->next = on_tok->next;
 152                on_tok->next = arg_tok;
 153                arg_tok->previous = on_tok;
 154                if (arg_tok->next)
 155                        arg_tok->next->previous = arg_tok;
 156                update_last(last);
 157        } else {
 158                arg_tok->previous = on_tok->previous;
 159                on_tok->previous = arg_tok;
 160                arg_tok->next = on_tok;
 161                if (arg_tok->previous)
 162                        arg_tok->previous->next = arg_tok;
 163                update_first(first);
 164        }
 165}
 166
 167static int check_if_different(struct trailer_item *in_tok,
 168                              struct trailer_item *arg_tok,
 169                              int check_all)
 170{
 171        enum action_where where = arg_tok->conf.where;
 172        do {
 173                if (!in_tok)
 174                        return 1;
 175                if (same_trailer(in_tok, arg_tok))
 176                        return 0;
 177                /*
 178                 * if we want to add a trailer after another one,
 179                 * we have to check those before this one
 180                 */
 181                in_tok = after_or_end(where) ? in_tok->previous : in_tok->next;
 182        } while (check_all);
 183        return 1;
 184}
 185
 186static void remove_from_list(struct trailer_item *item,
 187                             struct trailer_item **first,
 188                             struct trailer_item **last)
 189{
 190        struct trailer_item *next = item->next;
 191        struct trailer_item *previous = item->previous;
 192
 193        if (next) {
 194                item->next->previous = previous;
 195                item->next = NULL;
 196        } else if (last)
 197                *last = previous;
 198
 199        if (previous) {
 200                item->previous->next = next;
 201                item->previous = NULL;
 202        } else if (first)
 203                *first = next;
 204}
 205
 206static struct trailer_item *remove_first(struct trailer_item **first)
 207{
 208        struct trailer_item *item = *first;
 209        *first = item->next;
 210        if (item->next) {
 211                item->next->previous = NULL;
 212                item->next = NULL;
 213        }
 214        return item;
 215}
 216
 217static int read_from_command(struct child_process *cp, struct strbuf *buf)
 218{
 219        if (run_command(cp))
 220                return error("running trailer command '%s' failed", cp->argv[0]);
 221        if (strbuf_read(buf, cp->out, 1024) < 1)
 222                return error("reading from trailer command '%s' failed", cp->argv[0]);
 223        strbuf_trim(buf);
 224        return 0;
 225}
 226
 227static const char *apply_command(const char *command, const char *arg)
 228{
 229        struct strbuf cmd = STRBUF_INIT;
 230        struct strbuf buf = STRBUF_INIT;
 231        struct child_process cp;
 232        const char *argv[] = {NULL, NULL};
 233        const char *result;
 234
 235        strbuf_addstr(&cmd, command);
 236        if (arg)
 237                strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
 238
 239        argv[0] = cmd.buf;
 240        memset(&cp, 0, sizeof(cp));
 241        cp.argv = argv;
 242        cp.env = local_repo_env;
 243        cp.no_stdin = 1;
 244        cp.out = -1;
 245        cp.use_shell = 1;
 246
 247        if (read_from_command(&cp, &buf)) {
 248                strbuf_release(&buf);
 249                result = xstrdup("");
 250        } else
 251                result = strbuf_detach(&buf, NULL);
 252
 253        strbuf_release(&cmd);
 254        return result;
 255}
 256
 257static void apply_item_command(struct trailer_item *in_tok, struct trailer_item *arg_tok)
 258{
 259        if (arg_tok->conf.command) {
 260                const char *arg;
 261                if (arg_tok->value && arg_tok->value[0]) {
 262                        arg = arg_tok->value;
 263                } else {
 264                        if (in_tok && in_tok->value)
 265                                arg = xstrdup(in_tok->value);
 266                        else
 267                                arg = xstrdup("");
 268                }
 269                arg_tok->value = apply_command(arg_tok->conf.command, arg);
 270                free((char *)arg);
 271        }
 272}
 273
 274static void apply_arg_if_exists(struct trailer_item *in_tok,
 275                                struct trailer_item *arg_tok,
 276                                struct trailer_item *on_tok,
 277                                struct trailer_item **in_tok_first,
 278                                struct trailer_item **in_tok_last)
 279{
 280        switch (arg_tok->conf.if_exists) {
 281        case EXISTS_DO_NOTHING:
 282                free_trailer_item(arg_tok);
 283                break;
 284        case EXISTS_REPLACE:
 285                apply_item_command(in_tok, arg_tok);
 286                add_arg_to_input_list(on_tok, arg_tok,
 287                                      in_tok_first, in_tok_last);
 288                remove_from_list(in_tok, in_tok_first, in_tok_last);
 289                free_trailer_item(in_tok);
 290                break;
 291        case EXISTS_ADD:
 292                apply_item_command(in_tok, arg_tok);
 293                add_arg_to_input_list(on_tok, arg_tok,
 294                                      in_tok_first, in_tok_last);
 295                break;
 296        case EXISTS_ADD_IF_DIFFERENT:
 297                apply_item_command(in_tok, arg_tok);
 298                if (check_if_different(in_tok, arg_tok, 1))
 299                        add_arg_to_input_list(on_tok, arg_tok,
 300                                              in_tok_first, in_tok_last);
 301                else
 302                        free_trailer_item(arg_tok);
 303                break;
 304        case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR:
 305                apply_item_command(in_tok, arg_tok);
 306                if (check_if_different(on_tok, arg_tok, 0))
 307                        add_arg_to_input_list(on_tok, arg_tok,
 308                                              in_tok_first, in_tok_last);
 309                else
 310                        free_trailer_item(arg_tok);
 311                break;
 312        }
 313}
 314
 315static void apply_arg_if_missing(struct trailer_item **in_tok_first,
 316                                 struct trailer_item **in_tok_last,
 317                                 struct trailer_item *arg_tok)
 318{
 319        struct trailer_item **in_tok;
 320        enum action_where where;
 321
 322        switch (arg_tok->conf.if_missing) {
 323        case MISSING_DO_NOTHING:
 324                free_trailer_item(arg_tok);
 325                break;
 326        case MISSING_ADD:
 327                where = arg_tok->conf.where;
 328                in_tok = after_or_end(where) ? in_tok_last : in_tok_first;
 329                apply_item_command(NULL, arg_tok);
 330                if (*in_tok) {
 331                        add_arg_to_input_list(*in_tok, arg_tok,
 332                                              in_tok_first, in_tok_last);
 333                } else {
 334                        *in_tok_first = arg_tok;
 335                        *in_tok_last = arg_tok;
 336                }
 337                break;
 338        }
 339}
 340
 341static int find_same_and_apply_arg(struct trailer_item **in_tok_first,
 342                                   struct trailer_item **in_tok_last,
 343                                   struct trailer_item *arg_tok)
 344{
 345        struct trailer_item *in_tok;
 346        struct trailer_item *on_tok;
 347        struct trailer_item *following_tok;
 348
 349        enum action_where where = arg_tok->conf.where;
 350        int middle = (where == WHERE_AFTER) || (where == WHERE_BEFORE);
 351        int backwards = after_or_end(where);
 352        struct trailer_item *start_tok = backwards ? *in_tok_last : *in_tok_first;
 353
 354        for (in_tok = start_tok; in_tok; in_tok = following_tok) {
 355                following_tok = backwards ? in_tok->previous : in_tok->next;
 356                if (!same_token(in_tok, arg_tok))
 357                        continue;
 358                on_tok = middle ? in_tok : start_tok;
 359                apply_arg_if_exists(in_tok, arg_tok, on_tok,
 360                                    in_tok_first, in_tok_last);
 361                return 1;
 362        }
 363        return 0;
 364}
 365
 366static void process_trailers_lists(struct trailer_item **in_tok_first,
 367                                   struct trailer_item **in_tok_last,
 368                                   struct trailer_item **arg_tok_first)
 369{
 370        struct trailer_item *arg_tok;
 371        struct trailer_item *next_arg;
 372
 373        if (!*arg_tok_first)
 374                return;
 375
 376        for (arg_tok = *arg_tok_first; arg_tok; arg_tok = next_arg) {
 377                int applied = 0;
 378
 379                next_arg = arg_tok->next;
 380                remove_from_list(arg_tok, arg_tok_first, NULL);
 381
 382                applied = find_same_and_apply_arg(in_tok_first,
 383                                                  in_tok_last,
 384                                                  arg_tok);
 385
 386                if (!applied)
 387                        apply_arg_if_missing(in_tok_first,
 388                                             in_tok_last,
 389                                             arg_tok);
 390        }
 391}
 392
 393static int set_where(struct conf_info *item, const char *value)
 394{
 395        if (!strcasecmp("after", value))
 396                item->where = WHERE_AFTER;
 397        else if (!strcasecmp("before", value))
 398                item->where = WHERE_BEFORE;
 399        else if (!strcasecmp("end", value))
 400                item->where = WHERE_END;
 401        else if (!strcasecmp("start", value))
 402                item->where = WHERE_START;
 403        else
 404                return -1;
 405        return 0;
 406}
 407
 408static int set_if_exists(struct conf_info *item, const char *value)
 409{
 410        if (!strcasecmp("addIfDifferent", value))
 411                item->if_exists = EXISTS_ADD_IF_DIFFERENT;
 412        else if (!strcasecmp("addIfDifferentNeighbor", value))
 413                item->if_exists = EXISTS_ADD_IF_DIFFERENT_NEIGHBOR;
 414        else if (!strcasecmp("add", value))
 415                item->if_exists = EXISTS_ADD;
 416        else if (!strcasecmp("replace", value))
 417                item->if_exists = EXISTS_REPLACE;
 418        else if (!strcasecmp("doNothing", value))
 419                item->if_exists = EXISTS_DO_NOTHING;
 420        else
 421                return -1;
 422        return 0;
 423}
 424
 425static int set_if_missing(struct conf_info *item, const char *value)
 426{
 427        if (!strcasecmp("doNothing", value))
 428                item->if_missing = MISSING_DO_NOTHING;
 429        else if (!strcasecmp("add", value))
 430                item->if_missing = MISSING_ADD;
 431        else
 432                return -1;
 433        return 0;
 434}
 435
 436static void duplicate_conf(struct conf_info *dst, struct conf_info *src)
 437{
 438        *dst = *src;
 439        if (src->name)
 440                dst->name = xstrdup(src->name);
 441        if (src->key)
 442                dst->key = xstrdup(src->key);
 443        if (src->command)
 444                dst->command = xstrdup(src->command);
 445}
 446
 447static struct trailer_item *get_conf_item(const char *name)
 448{
 449        struct trailer_item *item;
 450        struct trailer_item *previous;
 451
 452        /* Look up item with same name */
 453        for (previous = NULL, item = first_conf_item;
 454             item;
 455             previous = item, item = item->next) {
 456                if (!strcasecmp(item->conf.name, name))
 457                        return item;
 458        }
 459
 460        /* Item does not already exists, create it */
 461        item = xcalloc(sizeof(struct trailer_item), 1);
 462        duplicate_conf(&item->conf, &default_conf_info);
 463        item->conf.name = xstrdup(name);
 464
 465        if (!previous)
 466                first_conf_item = item;
 467        else {
 468                previous->next = item;
 469                item->previous = previous;
 470        }
 471
 472        return item;
 473}
 474
 475enum trailer_info_type { TRAILER_KEY, TRAILER_COMMAND, TRAILER_WHERE,
 476                         TRAILER_IF_EXISTS, TRAILER_IF_MISSING };
 477
 478static struct {
 479        const char *name;
 480        enum trailer_info_type type;
 481} trailer_config_items[] = {
 482        { "key", TRAILER_KEY },
 483        { "command", TRAILER_COMMAND },
 484        { "where", TRAILER_WHERE },
 485        { "ifexists", TRAILER_IF_EXISTS },
 486        { "ifmissing", TRAILER_IF_MISSING }
 487};
 488
 489static int git_trailer_default_config(const char *conf_key, const char *value, void *cb)
 490{
 491        const char *trailer_item, *variable_name;
 492
 493        if (!skip_prefix(conf_key, "trailer.", &trailer_item))
 494                return 0;
 495
 496        variable_name = strrchr(trailer_item, '.');
 497        if (!variable_name) {
 498                if (!strcmp(trailer_item, "where")) {
 499                        if (set_where(&default_conf_info, value) < 0)
 500                                warning(_("unknown value '%s' for key '%s'"),
 501                                        value, conf_key);
 502                } else if (!strcmp(trailer_item, "ifexists")) {
 503                        if (set_if_exists(&default_conf_info, value) < 0)
 504                                warning(_("unknown value '%s' for key '%s'"),
 505                                        value, conf_key);
 506                } else if (!strcmp(trailer_item, "ifmissing")) {
 507                        if (set_if_missing(&default_conf_info, value) < 0)
 508                                warning(_("unknown value '%s' for key '%s'"),
 509                                        value, conf_key);
 510                } else if (!strcmp(trailer_item, "separators")) {
 511                        separators = xstrdup(value);
 512                }
 513        }
 514        return 0;
 515}
 516
 517static int git_trailer_config(const char *conf_key, const char *value, void *cb)
 518{
 519        const char *trailer_item, *variable_name;
 520        struct trailer_item *item;
 521        struct conf_info *conf;
 522        char *name = NULL;
 523        enum trailer_info_type type;
 524        int i;
 525
 526        if (!skip_prefix(conf_key, "trailer.", &trailer_item))
 527                return 0;
 528
 529        variable_name = strrchr(trailer_item, '.');
 530        if (!variable_name)
 531                return 0;
 532
 533        variable_name++;
 534        for (i = 0; i < ARRAY_SIZE(trailer_config_items); i++) {
 535                if (strcmp(trailer_config_items[i].name, variable_name))
 536                        continue;
 537                name = xstrndup(trailer_item,  variable_name - trailer_item - 1);
 538                type = trailer_config_items[i].type;
 539                break;
 540        }
 541
 542        if (!name)
 543                return 0;
 544
 545        item = get_conf_item(name);
 546        conf = &item->conf;
 547        free(name);
 548
 549        switch (type) {
 550        case TRAILER_KEY:
 551                if (conf->key)
 552                        warning(_("more than one %s"), conf_key);
 553                conf->key = xstrdup(value);
 554                break;
 555        case TRAILER_COMMAND:
 556                if (conf->command)
 557                        warning(_("more than one %s"), conf_key);
 558                conf->command = xstrdup(value);
 559                break;
 560        case TRAILER_WHERE:
 561                if (set_where(conf, value))
 562                        warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 563                break;
 564        case TRAILER_IF_EXISTS:
 565                if (set_if_exists(conf, value))
 566                        warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 567                break;
 568        case TRAILER_IF_MISSING:
 569                if (set_if_missing(conf, value))
 570                        warning(_("unknown value '%s' for key '%s'"), value, conf_key);
 571                break;
 572        default:
 573                die("internal bug in trailer.c");
 574        }
 575        return 0;
 576}
 577
 578static int parse_trailer(struct strbuf *tok, struct strbuf *val, const char *trailer)
 579{
 580        size_t len;
 581        struct strbuf seps = STRBUF_INIT;
 582        strbuf_addstr(&seps, separators);
 583        strbuf_addch(&seps, '=');
 584        len = strcspn(trailer, seps.buf);
 585        strbuf_release(&seps);
 586        if (len == 0)
 587                return error(_("empty trailer token in trailer '%s'"), trailer);
 588        if (len < strlen(trailer)) {
 589                strbuf_add(tok, trailer, len);
 590                strbuf_trim(tok);
 591                strbuf_addstr(val, trailer + len + 1);
 592                strbuf_trim(val);
 593        } else {
 594                strbuf_addstr(tok, trailer);
 595                strbuf_trim(tok);
 596        }
 597        return 0;
 598}
 599
 600static const char *token_from_item(struct trailer_item *item, char *tok)
 601{
 602        if (item->conf.key)
 603                return item->conf.key;
 604        if (tok)
 605                return tok;
 606        return item->conf.name;
 607}
 608
 609static struct trailer_item *new_trailer_item(struct trailer_item *conf_item,
 610                                             char *tok, char *val)
 611{
 612        struct trailer_item *new = xcalloc(sizeof(*new), 1);
 613        new->value = val ? val : xstrdup("");
 614
 615        if (conf_item) {
 616                duplicate_conf(&new->conf, &conf_item->conf);
 617                new->token = xstrdup(token_from_item(conf_item, tok));
 618                free(tok);
 619        } else {
 620                duplicate_conf(&new->conf, &default_conf_info);
 621                new->token = tok;
 622        }
 623
 624        return new;
 625}
 626
 627static int token_matches_item(const char *tok, struct trailer_item *item, int tok_len)
 628{
 629        if (!strncasecmp(tok, item->conf.name, tok_len))
 630                return 1;
 631        return item->conf.key ? !strncasecmp(tok, item->conf.key, tok_len) : 0;
 632}
 633
 634static struct trailer_item *create_trailer_item(const char *string)
 635{
 636        struct strbuf tok = STRBUF_INIT;
 637        struct strbuf val = STRBUF_INIT;
 638        struct trailer_item *item;
 639        int tok_len;
 640
 641        if (parse_trailer(&tok, &val, string))
 642                return NULL;
 643
 644        tok_len = token_len_without_separator(tok.buf, tok.len);
 645
 646        /* Lookup if the token matches something in the config */
 647        for (item = first_conf_item; item; item = item->next) {
 648                if (token_matches_item(tok.buf, item, tok_len))
 649                        return new_trailer_item(item,
 650                                                strbuf_detach(&tok, NULL),
 651                                                strbuf_detach(&val, NULL));
 652        }
 653
 654        return new_trailer_item(NULL,
 655                                strbuf_detach(&tok, NULL),
 656                                strbuf_detach(&val, NULL));
 657}
 658
 659static void add_trailer_item(struct trailer_item **first,
 660                             struct trailer_item **last,
 661                             struct trailer_item *new)
 662{
 663        if (!new)
 664                return;
 665        if (!*last) {
 666                *first = new;
 667                *last = new;
 668        } else {
 669                (*last)->next = new;
 670                new->previous = *last;
 671                *last = new;
 672        }
 673}
 674
 675static struct trailer_item *process_command_line_args(struct string_list *trailers)
 676{
 677        struct trailer_item *arg_tok_first = NULL;
 678        struct trailer_item *arg_tok_last = NULL;
 679        struct string_list_item *tr;
 680        struct trailer_item *item;
 681
 682        /* Add a trailer item for each configured trailer with a command */
 683        for (item = first_conf_item; item; item = item->next) {
 684                if (item->conf.command) {
 685                        struct trailer_item *new = new_trailer_item(item, NULL, NULL);
 686                        add_trailer_item(&arg_tok_first, &arg_tok_last, new);
 687                }
 688        }
 689
 690        /* Add a trailer item for each trailer on the command line */
 691        for_each_string_list_item(tr, trailers) {
 692                struct trailer_item *new = create_trailer_item(tr->string);
 693                add_trailer_item(&arg_tok_first, &arg_tok_last, new);
 694        }
 695
 696        return arg_tok_first;
 697}
 698
 699static struct strbuf **read_input_file(const char *file)
 700{
 701        struct strbuf **lines;
 702        struct strbuf sb = STRBUF_INIT;
 703
 704        if (file) {
 705                if (strbuf_read_file(&sb, file, 0) < 0)
 706                        die_errno(_("could not read input file '%s'"), file);
 707        } else {
 708                if (strbuf_read(&sb, fileno(stdin), 0) < 0)
 709                        die_errno(_("could not read from stdin"));
 710        }
 711
 712        lines = strbuf_split(&sb, '\n');
 713
 714        strbuf_release(&sb);
 715
 716        return lines;
 717}
 718
 719/*
 720 * Return the (0 based) index of the start of the patch or the line
 721 * count if there is no patch in the message.
 722 */
 723static int find_patch_start(struct strbuf **lines, int count)
 724{
 725        int i;
 726
 727        /* Get the start of the patch part if any */
 728        for (i = 0; i < count; i++) {
 729                if (starts_with(lines[i]->buf, "---"))
 730                        return i;
 731        }
 732
 733        return count;
 734}
 735
 736/*
 737 * Return the (0 based) index of the first trailer line or count if
 738 * there are no trailers. Trailers are searched only in the lines from
 739 * index (count - 1) down to index 0.
 740 */
 741static int find_trailer_start(struct strbuf **lines, int count)
 742{
 743        int start, only_spaces = 1;
 744
 745        /*
 746         * Get the start of the trailers by looking starting from the end
 747         * for a line with only spaces before lines with one separator.
 748         */
 749        for (start = count - 1; start >= 0; start--) {
 750                if (lines[start]->buf[0] == comment_line_char)
 751                        continue;
 752                if (contains_only_spaces(lines[start]->buf)) {
 753                        if (only_spaces)
 754                                continue;
 755                        return start + 1;
 756                }
 757                if (strcspn(lines[start]->buf, separators) < lines[start]->len) {
 758                        if (only_spaces)
 759                                only_spaces = 0;
 760                        continue;
 761                }
 762                return count;
 763        }
 764
 765        return only_spaces ? count : 0;
 766}
 767
 768static int has_blank_line_before(struct strbuf **lines, int start)
 769{
 770        for (;start >= 0; start--) {
 771                if (lines[start]->buf[0] == comment_line_char)
 772                        continue;
 773                return contains_only_spaces(lines[start]->buf);
 774        }
 775        return 0;
 776}
 777
 778static void print_lines(struct strbuf **lines, int start, int end)
 779{
 780        int i;
 781        for (i = start; lines[i] && i < end; i++)
 782                printf("%s", lines[i]->buf);
 783}
 784
 785static int process_input_file(struct strbuf **lines,
 786                              struct trailer_item **in_tok_first,
 787                              struct trailer_item **in_tok_last)
 788{
 789        int count = 0;
 790        int patch_start, trailer_start, i;
 791
 792        /* Get the line count */
 793        while (lines[count])
 794                count++;
 795
 796        patch_start = find_patch_start(lines, count);
 797        trailer_start = find_trailer_start(lines, patch_start);
 798
 799        /* Print lines before the trailers as is */
 800        print_lines(lines, 0, trailer_start);
 801
 802        if (!has_blank_line_before(lines, trailer_start - 1))
 803                printf("\n");
 804
 805        /* Parse trailer lines */
 806        for (i = trailer_start; i < patch_start; i++) {
 807                struct trailer_item *new = create_trailer_item(lines[i]->buf);
 808                add_trailer_item(in_tok_first, in_tok_last, new);
 809        }
 810
 811        return patch_start;
 812}
 813
 814static void free_all(struct trailer_item **first)
 815{
 816        while (*first) {
 817                struct trailer_item *item = remove_first(first);
 818                free_trailer_item(item);
 819        }
 820}
 821
 822void process_trailers(const char *file, int trim_empty, struct string_list *trailers)
 823{
 824        struct trailer_item *in_tok_first = NULL;
 825        struct trailer_item *in_tok_last = NULL;
 826        struct trailer_item *arg_tok_first;
 827        struct strbuf **lines;
 828        int patch_start;
 829
 830        /* Default config must be setup first */
 831        git_config(git_trailer_default_config, NULL);
 832        git_config(git_trailer_config, NULL);
 833
 834        lines = read_input_file(file);
 835
 836        /* Print the lines before the trailers */
 837        patch_start = process_input_file(lines, &in_tok_first, &in_tok_last);
 838
 839        arg_tok_first = process_command_line_args(trailers);
 840
 841        process_trailers_lists(&in_tok_first, &in_tok_last, &arg_tok_first);
 842
 843        print_all(in_tok_first, trim_empty);
 844
 845        free_all(&in_tok_first);
 846
 847        /* Print the lines after the trailers as is */
 848        print_lines(lines, patch_start, INT_MAX);
 849
 850        strbuf_list_free(lines);
 851}