submodule.con commit documentation fix: git difftool uses diff tools, not merge tools. (1e501a7)
   1#include "cache.h"
   2#include "submodule.h"
   3#include "dir.h"
   4#include "diff.h"
   5#include "commit.h"
   6#include "revision.h"
   7#include "run-command.h"
   8#include "diffcore.h"
   9#include "refs.h"
  10#include "string-list.h"
  11#include "sha1-array.h"
  12#include "argv-array.h"
  13
  14static struct string_list config_name_for_path;
  15static struct string_list config_fetch_recurse_submodules_for_name;
  16static struct string_list config_ignore_for_name;
  17static int config_fetch_recurse_submodules = RECURSE_SUBMODULES_ON_DEMAND;
  18static struct string_list changed_submodule_paths;
  19static int initialized_fetch_ref_tips;
  20static struct sha1_array ref_tips_before_fetch;
  21static struct sha1_array ref_tips_after_fetch;
  22
  23/*
  24 * The following flag is set if the .gitmodules file is unmerged. We then
  25 * disable recursion for all submodules where .git/config doesn't have a
  26 * matching config entry because we can't guess what might be configured in
  27 * .gitmodules unless the user resolves the conflict. When a command line
  28 * option is given (which always overrides configuration) this flag will be
  29 * ignored.
  30 */
  31static int gitmodules_is_unmerged;
  32
  33static int add_submodule_odb(const char *path)
  34{
  35        struct strbuf objects_directory = STRBUF_INIT;
  36        struct alternate_object_database *alt_odb;
  37        int ret = 0;
  38        const char *git_dir;
  39
  40        strbuf_addf(&objects_directory, "%s/.git", path);
  41        git_dir = read_gitfile(objects_directory.buf);
  42        if (git_dir) {
  43                strbuf_reset(&objects_directory);
  44                strbuf_addstr(&objects_directory, git_dir);
  45        }
  46        strbuf_addstr(&objects_directory, "/objects/");
  47        if (!is_directory(objects_directory.buf)) {
  48                ret = -1;
  49                goto done;
  50        }
  51        /* avoid adding it twice */
  52        for (alt_odb = alt_odb_list; alt_odb; alt_odb = alt_odb->next)
  53                if (alt_odb->name - alt_odb->base == objects_directory.len &&
  54                                !strncmp(alt_odb->base, objects_directory.buf,
  55                                        objects_directory.len))
  56                        goto done;
  57
  58        alt_odb = xmalloc(objects_directory.len + 42 + sizeof(*alt_odb));
  59        alt_odb->next = alt_odb_list;
  60        strcpy(alt_odb->base, objects_directory.buf);
  61        alt_odb->name = alt_odb->base + objects_directory.len;
  62        alt_odb->name[2] = '/';
  63        alt_odb->name[40] = '\0';
  64        alt_odb->name[41] = '\0';
  65        alt_odb_list = alt_odb;
  66        prepare_alt_odb();
  67done:
  68        strbuf_release(&objects_directory);
  69        return ret;
  70}
  71
  72void set_diffopt_flags_from_submodule_config(struct diff_options *diffopt,
  73                                             const char *path)
  74{
  75        struct string_list_item *path_option, *ignore_option;
  76        path_option = unsorted_string_list_lookup(&config_name_for_path, path);
  77        if (path_option) {
  78                ignore_option = unsorted_string_list_lookup(&config_ignore_for_name, path_option->util);
  79                if (ignore_option)
  80                        handle_ignore_submodules_arg(diffopt, ignore_option->util);
  81                else if (gitmodules_is_unmerged)
  82                        DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
  83        }
  84}
  85
  86int submodule_config(const char *var, const char *value, void *cb)
  87{
  88        if (!prefixcmp(var, "submodule."))
  89                return parse_submodule_config_option(var, value);
  90        else if (!strcmp(var, "fetch.recursesubmodules")) {
  91                config_fetch_recurse_submodules = parse_fetch_recurse_submodules_arg(var, value);
  92                return 0;
  93        }
  94        return 0;
  95}
  96
  97void gitmodules_config(void)
  98{
  99        const char *work_tree = get_git_work_tree();
 100        if (work_tree) {
 101                struct strbuf gitmodules_path = STRBUF_INIT;
 102                int pos;
 103                strbuf_addstr(&gitmodules_path, work_tree);
 104                strbuf_addstr(&gitmodules_path, "/.gitmodules");
 105                if (read_cache() < 0)
 106                        die("index file corrupt");
 107                pos = cache_name_pos(".gitmodules", 11);
 108                if (pos < 0) { /* .gitmodules not found or isn't merged */
 109                        pos = -1 - pos;
 110                        if (active_nr > pos) {  /* there is a .gitmodules */
 111                                const struct cache_entry *ce = active_cache[pos];
 112                                if (ce_namelen(ce) == 11 &&
 113                                    !memcmp(ce->name, ".gitmodules", 11))
 114                                        gitmodules_is_unmerged = 1;
 115                        }
 116                }
 117
 118                if (!gitmodules_is_unmerged)
 119                        git_config_from_file(submodule_config, gitmodules_path.buf, NULL);
 120                strbuf_release(&gitmodules_path);
 121        }
 122}
 123
 124int parse_submodule_config_option(const char *var, const char *value)
 125{
 126        int len;
 127        struct string_list_item *config;
 128        struct strbuf submodname = STRBUF_INIT;
 129
 130        var += 10;              /* Skip "submodule." */
 131
 132        len = strlen(var);
 133        if ((len > 5) && !strcmp(var + len - 5, ".path")) {
 134                strbuf_add(&submodname, var, len - 5);
 135                config = unsorted_string_list_lookup(&config_name_for_path, value);
 136                if (config)
 137                        free(config->util);
 138                else
 139                        config = string_list_append(&config_name_for_path, xstrdup(value));
 140                config->util = strbuf_detach(&submodname, NULL);
 141                strbuf_release(&submodname);
 142        } else if ((len > 23) && !strcmp(var + len - 23, ".fetchrecursesubmodules")) {
 143                strbuf_add(&submodname, var, len - 23);
 144                config = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, submodname.buf);
 145                if (!config)
 146                        config = string_list_append(&config_fetch_recurse_submodules_for_name,
 147                                                    strbuf_detach(&submodname, NULL));
 148                config->util = (void *)(intptr_t)parse_fetch_recurse_submodules_arg(var, value);
 149                strbuf_release(&submodname);
 150        } else if ((len > 7) && !strcmp(var + len - 7, ".ignore")) {
 151                if (strcmp(value, "untracked") && strcmp(value, "dirty") &&
 152                    strcmp(value, "all") && strcmp(value, "none")) {
 153                        warning("Invalid parameter \"%s\" for config option \"submodule.%s.ignore\"", value, var);
 154                        return 0;
 155                }
 156
 157                strbuf_add(&submodname, var, len - 7);
 158                config = unsorted_string_list_lookup(&config_ignore_for_name, submodname.buf);
 159                if (config)
 160                        free(config->util);
 161                else
 162                        config = string_list_append(&config_ignore_for_name,
 163                                                    strbuf_detach(&submodname, NULL));
 164                strbuf_release(&submodname);
 165                config->util = xstrdup(value);
 166                return 0;
 167        }
 168        return 0;
 169}
 170
 171void handle_ignore_submodules_arg(struct diff_options *diffopt,
 172                                  const char *arg)
 173{
 174        DIFF_OPT_CLR(diffopt, IGNORE_SUBMODULES);
 175        DIFF_OPT_CLR(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 176        DIFF_OPT_CLR(diffopt, IGNORE_DIRTY_SUBMODULES);
 177
 178        if (!strcmp(arg, "all"))
 179                DIFF_OPT_SET(diffopt, IGNORE_SUBMODULES);
 180        else if (!strcmp(arg, "untracked"))
 181                DIFF_OPT_SET(diffopt, IGNORE_UNTRACKED_IN_SUBMODULES);
 182        else if (!strcmp(arg, "dirty"))
 183                DIFF_OPT_SET(diffopt, IGNORE_DIRTY_SUBMODULES);
 184        else if (strcmp(arg, "none"))
 185                die("bad --ignore-submodules argument: %s", arg);
 186}
 187
 188static int prepare_submodule_summary(struct rev_info *rev, const char *path,
 189                struct commit *left, struct commit *right,
 190                int *fast_forward, int *fast_backward)
 191{
 192        struct commit_list *merge_bases, *list;
 193
 194        init_revisions(rev, NULL);
 195        setup_revisions(0, NULL, rev, NULL);
 196        rev->left_right = 1;
 197        rev->first_parent_only = 1;
 198        left->object.flags |= SYMMETRIC_LEFT;
 199        add_pending_object(rev, &left->object, path);
 200        add_pending_object(rev, &right->object, path);
 201        merge_bases = get_merge_bases(left, right, 1);
 202        if (merge_bases) {
 203                if (merge_bases->item == left)
 204                        *fast_forward = 1;
 205                else if (merge_bases->item == right)
 206                        *fast_backward = 1;
 207        }
 208        for (list = merge_bases; list; list = list->next) {
 209                list->item->object.flags |= UNINTERESTING;
 210                add_pending_object(rev, &list->item->object,
 211                        sha1_to_hex(list->item->object.sha1));
 212        }
 213        return prepare_revision_walk(rev);
 214}
 215
 216static void print_submodule_summary(struct rev_info *rev, FILE *f,
 217                const char *del, const char *add, const char *reset)
 218{
 219        static const char format[] = "  %m %s";
 220        struct strbuf sb = STRBUF_INIT;
 221        struct commit *commit;
 222
 223        while ((commit = get_revision(rev))) {
 224                struct pretty_print_context ctx = {0};
 225                ctx.date_mode = rev->date_mode;
 226                strbuf_setlen(&sb, 0);
 227                if (commit->object.flags & SYMMETRIC_LEFT) {
 228                        if (del)
 229                                strbuf_addstr(&sb, del);
 230                }
 231                else if (add)
 232                        strbuf_addstr(&sb, add);
 233                format_commit_message(commit, format, &sb, &ctx);
 234                if (reset)
 235                        strbuf_addstr(&sb, reset);
 236                strbuf_addch(&sb, '\n');
 237                fprintf(f, "%s", sb.buf);
 238        }
 239        strbuf_release(&sb);
 240}
 241
 242int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 243{
 244        switch (git_config_maybe_bool(opt, arg)) {
 245        case 1:
 246                return RECURSE_SUBMODULES_ON;
 247        case 0:
 248                return RECURSE_SUBMODULES_OFF;
 249        default:
 250                if (!strcmp(arg, "on-demand"))
 251                        return RECURSE_SUBMODULES_ON_DEMAND;
 252                die("bad %s argument: %s", opt, arg);
 253        }
 254}
 255
 256void show_submodule_summary(FILE *f, const char *path,
 257                unsigned char one[20], unsigned char two[20],
 258                unsigned dirty_submodule,
 259                const char *del, const char *add, const char *reset)
 260{
 261        struct rev_info rev;
 262        struct commit *left = left, *right = right;
 263        const char *message = NULL;
 264        struct strbuf sb = STRBUF_INIT;
 265        int fast_forward = 0, fast_backward = 0;
 266
 267        if (is_null_sha1(two))
 268                message = "(submodule deleted)";
 269        else if (add_submodule_odb(path))
 270                message = "(not checked out)";
 271        else if (is_null_sha1(one))
 272                message = "(new submodule)";
 273        else if (!(left = lookup_commit_reference(one)) ||
 274                 !(right = lookup_commit_reference(two)))
 275                message = "(commits not present)";
 276
 277        if (!message &&
 278            prepare_submodule_summary(&rev, path, left, right,
 279                                        &fast_forward, &fast_backward))
 280                message = "(revision walker failed)";
 281
 282        if (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED)
 283                fprintf(f, "Submodule %s contains untracked content\n", path);
 284        if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 285                fprintf(f, "Submodule %s contains modified content\n", path);
 286
 287        if (!hashcmp(one, two)) {
 288                strbuf_release(&sb);
 289                return;
 290        }
 291
 292        strbuf_addf(&sb, "Submodule %s %s..", path,
 293                        find_unique_abbrev(one, DEFAULT_ABBREV));
 294        if (!fast_backward && !fast_forward)
 295                strbuf_addch(&sb, '.');
 296        strbuf_addf(&sb, "%s", find_unique_abbrev(two, DEFAULT_ABBREV));
 297        if (message)
 298                strbuf_addf(&sb, " %s\n", message);
 299        else
 300                strbuf_addf(&sb, "%s:\n", fast_backward ? " (rewind)" : "");
 301        fwrite(sb.buf, sb.len, 1, f);
 302
 303        if (!message) {
 304                print_submodule_summary(&rev, f, del, add, reset);
 305                clear_commit_marks(left, ~0);
 306                clear_commit_marks(right, ~0);
 307        }
 308
 309        strbuf_release(&sb);
 310}
 311
 312void set_config_fetch_recurse_submodules(int value)
 313{
 314        config_fetch_recurse_submodules = value;
 315}
 316
 317static int has_remote(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
 318{
 319        return 1;
 320}
 321
 322static int submodule_needs_pushing(const char *path, const unsigned char sha1[20])
 323{
 324        if (add_submodule_odb(path) || !lookup_commit_reference(sha1))
 325                return 0;
 326
 327        if (for_each_remote_ref_submodule(path, has_remote, NULL) > 0) {
 328                struct child_process cp;
 329                const char *argv[] = {"rev-list", NULL, "--not", "--remotes", "-n", "1" , NULL};
 330                struct strbuf buf = STRBUF_INIT;
 331                int needs_pushing = 0;
 332
 333                argv[1] = sha1_to_hex(sha1);
 334                memset(&cp, 0, sizeof(cp));
 335                cp.argv = argv;
 336                cp.env = local_repo_env;
 337                cp.git_cmd = 1;
 338                cp.no_stdin = 1;
 339                cp.out = -1;
 340                cp.dir = path;
 341                if (start_command(&cp))
 342                        die("Could not run 'git rev-list %s --not --remotes -n 1' command in submodule %s",
 343                                sha1_to_hex(sha1), path);
 344                if (strbuf_read(&buf, cp.out, 41))
 345                        needs_pushing = 1;
 346                finish_command(&cp);
 347                close(cp.out);
 348                strbuf_release(&buf);
 349                return needs_pushing;
 350        }
 351
 352        return 0;
 353}
 354
 355static void collect_submodules_from_diff(struct diff_queue_struct *q,
 356                                         struct diff_options *options,
 357                                         void *data)
 358{
 359        int i;
 360        int *needs_pushing = data;
 361
 362        for (i = 0; i < q->nr; i++) {
 363                struct diff_filepair *p = q->queue[i];
 364                if (!S_ISGITLINK(p->two->mode))
 365                        continue;
 366                if (submodule_needs_pushing(p->two->path, p->two->sha1)) {
 367                        *needs_pushing = 1;
 368                        break;
 369                }
 370        }
 371}
 372
 373
 374static void commit_need_pushing(struct commit *commit, struct commit_list *parent, int *needs_pushing)
 375{
 376        const unsigned char (*parents)[20];
 377        unsigned int i, n;
 378        struct rev_info rev;
 379
 380        n = commit_list_count(parent);
 381        parents = xmalloc(n * sizeof(*parents));
 382
 383        for (i = 0; i < n; i++) {
 384                hashcpy((unsigned char *)(parents + i), parent->item->object.sha1);
 385                parent = parent->next;
 386        }
 387
 388        init_revisions(&rev, NULL);
 389        rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 390        rev.diffopt.format_callback = collect_submodules_from_diff;
 391        rev.diffopt.format_callback_data = needs_pushing;
 392        diff_tree_combined(commit->object.sha1, parents, n, 1, &rev);
 393
 394        free(parents);
 395}
 396
 397int check_submodule_needs_pushing(unsigned char new_sha1[20], const char *remotes_name)
 398{
 399        struct rev_info rev;
 400        struct commit *commit;
 401        const char *argv[] = {NULL, NULL, "--not", "NULL", NULL};
 402        int argc = ARRAY_SIZE(argv) - 1;
 403        char *sha1_copy;
 404        int needs_pushing = 0;
 405        struct strbuf remotes_arg = STRBUF_INIT;
 406
 407        strbuf_addf(&remotes_arg, "--remotes=%s", remotes_name);
 408        init_revisions(&rev, NULL);
 409        sha1_copy = xstrdup(sha1_to_hex(new_sha1));
 410        argv[1] = sha1_copy;
 411        argv[3] = remotes_arg.buf;
 412        setup_revisions(argc, argv, &rev, NULL);
 413        if (prepare_revision_walk(&rev))
 414                die("revision walk setup failed");
 415
 416        while ((commit = get_revision(&rev)) && !needs_pushing)
 417                commit_need_pushing(commit, commit->parents, &needs_pushing);
 418
 419        free(sha1_copy);
 420        strbuf_release(&remotes_arg);
 421
 422        return needs_pushing;
 423}
 424
 425static int is_submodule_commit_present(const char *path, unsigned char sha1[20])
 426{
 427        int is_present = 0;
 428        if (!add_submodule_odb(path) && lookup_commit_reference(sha1)) {
 429                /* Even if the submodule is checked out and the commit is
 430                 * present, make sure it is reachable from a ref. */
 431                struct child_process cp;
 432                const char *argv[] = {"rev-list", "-n", "1", NULL, "--not", "--all", NULL};
 433                struct strbuf buf = STRBUF_INIT;
 434
 435                argv[3] = sha1_to_hex(sha1);
 436                memset(&cp, 0, sizeof(cp));
 437                cp.argv = argv;
 438                cp.env = local_repo_env;
 439                cp.git_cmd = 1;
 440                cp.no_stdin = 1;
 441                cp.out = -1;
 442                cp.dir = path;
 443                if (!run_command(&cp) && !strbuf_read(&buf, cp.out, 1024))
 444                        is_present = 1;
 445
 446                close(cp.out);
 447                strbuf_release(&buf);
 448        }
 449        return is_present;
 450}
 451
 452static void submodule_collect_changed_cb(struct diff_queue_struct *q,
 453                                         struct diff_options *options,
 454                                         void *data)
 455{
 456        int i;
 457        for (i = 0; i < q->nr; i++) {
 458                struct diff_filepair *p = q->queue[i];
 459                if (!S_ISGITLINK(p->two->mode))
 460                        continue;
 461
 462                if (S_ISGITLINK(p->one->mode)) {
 463                        /* NEEDSWORK: We should honor the name configured in
 464                         * the .gitmodules file of the commit we are examining
 465                         * here to be able to correctly follow submodules
 466                         * being moved around. */
 467                        struct string_list_item *path;
 468                        path = unsorted_string_list_lookup(&changed_submodule_paths, p->two->path);
 469                        if (!path && !is_submodule_commit_present(p->two->path, p->two->sha1))
 470                                string_list_append(&changed_submodule_paths, xstrdup(p->two->path));
 471                } else {
 472                        /* Submodule is new or was moved here */
 473                        /* NEEDSWORK: When the .git directories of submodules
 474                         * live inside the superprojects .git directory some
 475                         * day we should fetch new submodules directly into
 476                         * that location too when config or options request
 477                         * that so they can be checked out from there. */
 478                        continue;
 479                }
 480        }
 481}
 482
 483static int add_sha1_to_array(const char *ref, const unsigned char *sha1,
 484                             int flags, void *data)
 485{
 486        sha1_array_append(data, sha1);
 487        return 0;
 488}
 489
 490void check_for_new_submodule_commits(unsigned char new_sha1[20])
 491{
 492        if (!initialized_fetch_ref_tips) {
 493                for_each_ref(add_sha1_to_array, &ref_tips_before_fetch);
 494                initialized_fetch_ref_tips = 1;
 495        }
 496
 497        sha1_array_append(&ref_tips_after_fetch, new_sha1);
 498}
 499
 500static void add_sha1_to_argv(const unsigned char sha1[20], void *data)
 501{
 502        argv_array_push(data, sha1_to_hex(sha1));
 503}
 504
 505static void calculate_changed_submodule_paths(void)
 506{
 507        struct rev_info rev;
 508        struct commit *commit;
 509        struct argv_array argv = ARGV_ARRAY_INIT;
 510
 511        /* No need to check if there are no submodules configured */
 512        if (!config_name_for_path.nr)
 513                return;
 514
 515        init_revisions(&rev, NULL);
 516        argv_array_push(&argv, "--"); /* argv[0] program name */
 517        sha1_array_for_each_unique(&ref_tips_after_fetch,
 518                                   add_sha1_to_argv, &argv);
 519        argv_array_push(&argv, "--not");
 520        sha1_array_for_each_unique(&ref_tips_before_fetch,
 521                                   add_sha1_to_argv, &argv);
 522        setup_revisions(argv.argc, argv.argv, &rev, NULL);
 523        if (prepare_revision_walk(&rev))
 524                die("revision walk setup failed");
 525
 526        /*
 527         * Collect all submodules (whether checked out or not) for which new
 528         * commits have been recorded upstream in "changed_submodule_paths".
 529         */
 530        while ((commit = get_revision(&rev))) {
 531                struct commit_list *parent = commit->parents;
 532                while (parent) {
 533                        struct diff_options diff_opts;
 534                        diff_setup(&diff_opts);
 535                        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 536                        diff_opts.output_format |= DIFF_FORMAT_CALLBACK;
 537                        diff_opts.format_callback = submodule_collect_changed_cb;
 538                        if (diff_setup_done(&diff_opts) < 0)
 539                                die("diff_setup_done failed");
 540                        diff_tree_sha1(parent->item->object.sha1, commit->object.sha1, "", &diff_opts);
 541                        diffcore_std(&diff_opts);
 542                        diff_flush(&diff_opts);
 543                        parent = parent->next;
 544                }
 545        }
 546
 547        argv_array_clear(&argv);
 548        sha1_array_clear(&ref_tips_before_fetch);
 549        sha1_array_clear(&ref_tips_after_fetch);
 550        initialized_fetch_ref_tips = 0;
 551}
 552
 553int fetch_populated_submodules(int num_options, const char **options,
 554                               const char *prefix, int command_line_option,
 555                               int quiet)
 556{
 557        int i, result = 0, argc = 0, default_argc;
 558        struct child_process cp;
 559        const char **argv;
 560        struct string_list_item *name_for_path;
 561        const char *work_tree = get_git_work_tree();
 562        if (!work_tree)
 563                goto out;
 564
 565        if (!the_index.initialized)
 566                if (read_cache() < 0)
 567                        die("index file corrupt");
 568
 569        /* 6: "fetch" (options) --recurse-submodules-default default "--submodule-prefix" prefix NULL */
 570        argv = xcalloc(num_options + 6, sizeof(const char *));
 571        argv[argc++] = "fetch";
 572        for (i = 0; i < num_options; i++)
 573                argv[argc++] = options[i];
 574        argv[argc++] = "--recurse-submodules-default";
 575        default_argc = argc++;
 576        argv[argc++] = "--submodule-prefix";
 577
 578        memset(&cp, 0, sizeof(cp));
 579        cp.argv = argv;
 580        cp.env = local_repo_env;
 581        cp.git_cmd = 1;
 582        cp.no_stdin = 1;
 583
 584        calculate_changed_submodule_paths();
 585
 586        for (i = 0; i < active_nr; i++) {
 587                struct strbuf submodule_path = STRBUF_INIT;
 588                struct strbuf submodule_git_dir = STRBUF_INIT;
 589                struct strbuf submodule_prefix = STRBUF_INIT;
 590                struct cache_entry *ce = active_cache[i];
 591                const char *git_dir, *name, *default_argv;
 592
 593                if (!S_ISGITLINK(ce->ce_mode))
 594                        continue;
 595
 596                name = ce->name;
 597                name_for_path = unsorted_string_list_lookup(&config_name_for_path, ce->name);
 598                if (name_for_path)
 599                        name = name_for_path->util;
 600
 601                default_argv = "yes";
 602                if (command_line_option == RECURSE_SUBMODULES_DEFAULT) {
 603                        struct string_list_item *fetch_recurse_submodules_option;
 604                        fetch_recurse_submodules_option = unsorted_string_list_lookup(&config_fetch_recurse_submodules_for_name, name);
 605                        if (fetch_recurse_submodules_option) {
 606                                if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_OFF)
 607                                        continue;
 608                                if ((intptr_t)fetch_recurse_submodules_option->util == RECURSE_SUBMODULES_ON_DEMAND) {
 609                                        if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 610                                                continue;
 611                                        default_argv = "on-demand";
 612                                }
 613                        } else {
 614                                if ((config_fetch_recurse_submodules == RECURSE_SUBMODULES_OFF) ||
 615                                    gitmodules_is_unmerged)
 616                                        continue;
 617                                if (config_fetch_recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) {
 618                                        if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 619                                                continue;
 620                                        default_argv = "on-demand";
 621                                }
 622                        }
 623                } else if (command_line_option == RECURSE_SUBMODULES_ON_DEMAND) {
 624                        if (!unsorted_string_list_lookup(&changed_submodule_paths, ce->name))
 625                                continue;
 626                        default_argv = "on-demand";
 627                }
 628
 629                strbuf_addf(&submodule_path, "%s/%s", work_tree, ce->name);
 630                strbuf_addf(&submodule_git_dir, "%s/.git", submodule_path.buf);
 631                strbuf_addf(&submodule_prefix, "%s%s/", prefix, ce->name);
 632                git_dir = read_gitfile(submodule_git_dir.buf);
 633                if (!git_dir)
 634                        git_dir = submodule_git_dir.buf;
 635                if (is_directory(git_dir)) {
 636                        if (!quiet)
 637                                printf("Fetching submodule %s%s\n", prefix, ce->name);
 638                        cp.dir = submodule_path.buf;
 639                        argv[default_argc] = default_argv;
 640                        argv[argc] = submodule_prefix.buf;
 641                        if (run_command(&cp))
 642                                result = 1;
 643                }
 644                strbuf_release(&submodule_path);
 645                strbuf_release(&submodule_git_dir);
 646                strbuf_release(&submodule_prefix);
 647        }
 648        free(argv);
 649out:
 650        string_list_clear(&changed_submodule_paths, 1);
 651        return result;
 652}
 653
 654unsigned is_submodule_modified(const char *path, int ignore_untracked)
 655{
 656        ssize_t len;
 657        struct child_process cp;
 658        const char *argv[] = {
 659                "status",
 660                "--porcelain",
 661                NULL,
 662                NULL,
 663        };
 664        struct strbuf buf = STRBUF_INIT;
 665        unsigned dirty_submodule = 0;
 666        const char *line, *next_line;
 667        const char *git_dir;
 668
 669        strbuf_addf(&buf, "%s/.git", path);
 670        git_dir = read_gitfile(buf.buf);
 671        if (!git_dir)
 672                git_dir = buf.buf;
 673        if (!is_directory(git_dir)) {
 674                strbuf_release(&buf);
 675                /* The submodule is not checked out, so it is not modified */
 676                return 0;
 677
 678        }
 679        strbuf_reset(&buf);
 680
 681        if (ignore_untracked)
 682                argv[2] = "-uno";
 683
 684        memset(&cp, 0, sizeof(cp));
 685        cp.argv = argv;
 686        cp.env = local_repo_env;
 687        cp.git_cmd = 1;
 688        cp.no_stdin = 1;
 689        cp.out = -1;
 690        cp.dir = path;
 691        if (start_command(&cp))
 692                die("Could not run git status --porcelain");
 693
 694        len = strbuf_read(&buf, cp.out, 1024);
 695        line = buf.buf;
 696        while (len > 2) {
 697                if ((line[0] == '?') && (line[1] == '?')) {
 698                        dirty_submodule |= DIRTY_SUBMODULE_UNTRACKED;
 699                        if (dirty_submodule & DIRTY_SUBMODULE_MODIFIED)
 700                                break;
 701                } else {
 702                        dirty_submodule |= DIRTY_SUBMODULE_MODIFIED;
 703                        if (ignore_untracked ||
 704                            (dirty_submodule & DIRTY_SUBMODULE_UNTRACKED))
 705                                break;
 706                }
 707                next_line = strchr(line, '\n');
 708                if (!next_line)
 709                        break;
 710                next_line++;
 711                len -= (next_line - line);
 712                line = next_line;
 713        }
 714        close(cp.out);
 715
 716        if (finish_command(&cp))
 717                die("git status --porcelain failed");
 718
 719        strbuf_release(&buf);
 720        return dirty_submodule;
 721}
 722
 723static int find_first_merges(struct object_array *result, const char *path,
 724                struct commit *a, struct commit *b)
 725{
 726        int i, j;
 727        struct object_array merges;
 728        struct commit *commit;
 729        int contains_another;
 730
 731        char merged_revision[42];
 732        const char *rev_args[] = { "rev-list", "--merges", "--ancestry-path",
 733                                   "--all", merged_revision, NULL };
 734        struct rev_info revs;
 735        struct setup_revision_opt rev_opts;
 736
 737        memset(&merges, 0, sizeof(merges));
 738        memset(result, 0, sizeof(struct object_array));
 739        memset(&rev_opts, 0, sizeof(rev_opts));
 740
 741        /* get all revisions that merge commit a */
 742        snprintf(merged_revision, sizeof(merged_revision), "^%s",
 743                        sha1_to_hex(a->object.sha1));
 744        init_revisions(&revs, NULL);
 745        rev_opts.submodule = path;
 746        setup_revisions(sizeof(rev_args)/sizeof(char *)-1, rev_args, &revs, &rev_opts);
 747
 748        /* save all revisions from the above list that contain b */
 749        if (prepare_revision_walk(&revs))
 750                die("revision walk setup failed");
 751        while ((commit = get_revision(&revs)) != NULL) {
 752                struct object *o = &(commit->object);
 753                if (in_merge_bases(b, &commit, 1))
 754                        add_object_array(o, NULL, &merges);
 755        }
 756
 757        /* Now we've got all merges that contain a and b. Prune all
 758         * merges that contain another found merge and save them in
 759         * result.
 760         */
 761        for (i = 0; i < merges.nr; i++) {
 762                struct commit *m1 = (struct commit *) merges.objects[i].item;
 763
 764                contains_another = 0;
 765                for (j = 0; j < merges.nr; j++) {
 766                        struct commit *m2 = (struct commit *) merges.objects[j].item;
 767                        if (i != j && in_merge_bases(m2, &m1, 1)) {
 768                                contains_another = 1;
 769                                break;
 770                        }
 771                }
 772
 773                if (!contains_another)
 774                        add_object_array(merges.objects[i].item,
 775                                         merges.objects[i].name, result);
 776        }
 777
 778        free(merges.objects);
 779        return result->nr;
 780}
 781
 782static void print_commit(struct commit *commit)
 783{
 784        struct strbuf sb = STRBUF_INIT;
 785        struct pretty_print_context ctx = {0};
 786        ctx.date_mode = DATE_NORMAL;
 787        format_commit_message(commit, " %h: %m %s", &sb, &ctx);
 788        fprintf(stderr, "%s\n", sb.buf);
 789        strbuf_release(&sb);
 790}
 791
 792#define MERGE_WARNING(path, msg) \
 793        warning("Failed to merge submodule %s (%s)", path, msg);
 794
 795int merge_submodule(unsigned char result[20], const char *path,
 796                    const unsigned char base[20], const unsigned char a[20],
 797                    const unsigned char b[20])
 798{
 799        struct commit *commit_base, *commit_a, *commit_b;
 800        int parent_count;
 801        struct object_array merges;
 802
 803        int i;
 804
 805        /* store a in result in case we fail */
 806        hashcpy(result, a);
 807
 808        /* we can not handle deletion conflicts */
 809        if (is_null_sha1(base))
 810                return 0;
 811        if (is_null_sha1(a))
 812                return 0;
 813        if (is_null_sha1(b))
 814                return 0;
 815
 816        if (add_submodule_odb(path)) {
 817                MERGE_WARNING(path, "not checked out");
 818                return 0;
 819        }
 820
 821        if (!(commit_base = lookup_commit_reference(base)) ||
 822            !(commit_a = lookup_commit_reference(a)) ||
 823            !(commit_b = lookup_commit_reference(b))) {
 824                MERGE_WARNING(path, "commits not present");
 825                return 0;
 826        }
 827
 828        /* check whether both changes are forward */
 829        if (!in_merge_bases(commit_base, &commit_a, 1) ||
 830            !in_merge_bases(commit_base, &commit_b, 1)) {
 831                MERGE_WARNING(path, "commits don't follow merge-base");
 832                return 0;
 833        }
 834
 835        /* Case #1: a is contained in b or vice versa */
 836        if (in_merge_bases(commit_a, &commit_b, 1)) {
 837                hashcpy(result, b);
 838                return 1;
 839        }
 840        if (in_merge_bases(commit_b, &commit_a, 1)) {
 841                hashcpy(result, a);
 842                return 1;
 843        }
 844
 845        /*
 846         * Case #2: There are one or more merges that contain a and b in
 847         * the submodule. If there is only one, then present it as a
 848         * suggestion to the user, but leave it marked unmerged so the
 849         * user needs to confirm the resolution.
 850         */
 851
 852        /* find commit which merges them */
 853        parent_count = find_first_merges(&merges, path, commit_a, commit_b);
 854        switch (parent_count) {
 855        case 0:
 856                MERGE_WARNING(path, "merge following commits not found");
 857                break;
 858
 859        case 1:
 860                MERGE_WARNING(path, "not fast-forward");
 861                fprintf(stderr, "Found a possible merge resolution "
 862                                "for the submodule:\n");
 863                print_commit((struct commit *) merges.objects[0].item);
 864                fprintf(stderr,
 865                        "If this is correct simply add it to the index "
 866                        "for example\n"
 867                        "by using:\n\n"
 868                        "  git update-index --cacheinfo 160000 %s \"%s\"\n\n"
 869                        "which will accept this suggestion.\n",
 870                        sha1_to_hex(merges.objects[0].item->sha1), path);
 871                break;
 872
 873        default:
 874                MERGE_WARNING(path, "multiple merges found");
 875                for (i = 0; i < merges.nr; i++)
 876                        print_commit((struct commit *) merges.objects[i].item);
 877        }
 878
 879        free(merges.objects);
 880        return 0;
 881}