builtin / pull.con commit wt-status.h: drop stdio.h include (7a06fb0)
   1/*
   2 * Builtin "git pull"
   3 *
   4 * Based on git-pull.sh by Junio C Hamano
   5 *
   6 * Fetch one or more remote refs and merge it/them into the current HEAD.
   7 */
   8#define USE_THE_INDEX_COMPATIBILITY_MACROS
   9#include "cache.h"
  10#include "config.h"
  11#include "builtin.h"
  12#include "parse-options.h"
  13#include "exec-cmd.h"
  14#include "run-command.h"
  15#include "sha1-array.h"
  16#include "remote.h"
  17#include "dir.h"
  18#include "refs.h"
  19#include "refspec.h"
  20#include "revision.h"
  21#include "submodule.h"
  22#include "submodule-config.h"
  23#include "tempfile.h"
  24#include "lockfile.h"
  25#include "wt-status.h"
  26#include "commit-reach.h"
  27#include "sequencer.h"
  28
  29enum rebase_type {
  30        REBASE_INVALID = -1,
  31        REBASE_FALSE = 0,
  32        REBASE_TRUE,
  33        REBASE_PRESERVE,
  34        REBASE_MERGES,
  35        REBASE_INTERACTIVE
  36};
  37
  38/**
  39 * Parses the value of --rebase. If value is a false value, returns
  40 * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is
  41 * "merges", returns REBASE_MERGES. If value is "preserve", returns
  42 * REBASE_PRESERVE. If value is a invalid value, dies with a fatal error if
  43 * fatal is true, otherwise returns REBASE_INVALID.
  44 */
  45static enum rebase_type parse_config_rebase(const char *key, const char *value,
  46                int fatal)
  47{
  48        int v = git_parse_maybe_bool(value);
  49
  50        if (!v)
  51                return REBASE_FALSE;
  52        else if (v > 0)
  53                return REBASE_TRUE;
  54        else if (!strcmp(value, "preserve") || !strcmp(value, "p"))
  55                return REBASE_PRESERVE;
  56        else if (!strcmp(value, "merges") || !strcmp(value, "m"))
  57                return REBASE_MERGES;
  58        else if (!strcmp(value, "interactive") || !strcmp(value, "i"))
  59                return REBASE_INTERACTIVE;
  60        /*
  61         * Please update _git_config() in git-completion.bash when you
  62         * add new rebase modes.
  63         */
  64
  65        if (fatal)
  66                die(_("Invalid value for %s: %s"), key, value);
  67        else
  68                error(_("Invalid value for %s: %s"), key, value);
  69
  70        return REBASE_INVALID;
  71}
  72
  73/**
  74 * Callback for --rebase, which parses arg with parse_config_rebase().
  75 */
  76static int parse_opt_rebase(const struct option *opt, const char *arg, int unset)
  77{
  78        enum rebase_type *value = opt->value;
  79
  80        if (arg)
  81                *value = parse_config_rebase("--rebase", arg, 0);
  82        else
  83                *value = unset ? REBASE_FALSE : REBASE_TRUE;
  84        return *value == REBASE_INVALID ? -1 : 0;
  85}
  86
  87static const char * const pull_usage[] = {
  88        N_("git pull [<options>] [<repository> [<refspec>...]]"),
  89        NULL
  90};
  91
  92/* Shared options */
  93static int opt_verbosity;
  94static char *opt_progress;
  95static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
  96
  97/* Options passed to git-merge or git-rebase */
  98static enum rebase_type opt_rebase = -1;
  99static char *opt_diffstat;
 100static char *opt_log;
 101static char *opt_signoff;
 102static char *opt_squash;
 103static char *opt_commit;
 104static char *opt_edit;
 105static char *cleanup_arg;
 106static char *opt_ff;
 107static char *opt_verify_signatures;
 108static int opt_autostash = -1;
 109static int config_autostash;
 110static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
 111static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
 112static char *opt_gpg_sign;
 113static int opt_allow_unrelated_histories;
 114
 115/* Options passed to git-fetch */
 116static char *opt_all;
 117static char *opt_append;
 118static char *opt_upload_pack;
 119static int opt_force;
 120static char *opt_tags;
 121static char *opt_prune;
 122static char *max_children;
 123static int opt_dry_run;
 124static char *opt_keep;
 125static char *opt_depth;
 126static char *opt_unshallow;
 127static char *opt_update_shallow;
 128static char *opt_refmap;
 129static char *opt_ipv4;
 130static char *opt_ipv6;
 131
 132static struct option pull_options[] = {
 133        /* Shared options */
 134        OPT__VERBOSITY(&opt_verbosity),
 135        OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
 136                N_("force progress reporting"),
 137                PARSE_OPT_NOARG),
 138        { OPTION_CALLBACK, 0, "recurse-submodules",
 139                   &recurse_submodules, N_("on-demand"),
 140                   N_("control for recursive fetching of submodules"),
 141                   PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules },
 142
 143        /* Options passed to git-merge or git-rebase */
 144        OPT_GROUP(N_("Options related to merging")),
 145        { OPTION_CALLBACK, 'r', "rebase", &opt_rebase,
 146          "(false|true|merges|preserve|interactive)",
 147          N_("incorporate changes by rebasing rather than merging"),
 148          PARSE_OPT_OPTARG, parse_opt_rebase },
 149        OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
 150                N_("do not show a diffstat at the end of the merge"),
 151                PARSE_OPT_NOARG | PARSE_OPT_NONEG),
 152        OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
 153                N_("show a diffstat at the end of the merge"),
 154                PARSE_OPT_NOARG),
 155        OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
 156                N_("(synonym to --stat)"),
 157                PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
 158        OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
 159                N_("add (at most <n>) entries from shortlog to merge commit message"),
 160                PARSE_OPT_OPTARG),
 161        OPT_PASSTHRU(0, "signoff", &opt_signoff, NULL,
 162                N_("add Signed-off-by:"),
 163                PARSE_OPT_OPTARG),
 164        OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
 165                N_("create a single commit instead of doing a merge"),
 166                PARSE_OPT_NOARG),
 167        OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
 168                N_("perform a commit if the merge succeeds (default)"),
 169                PARSE_OPT_NOARG),
 170        OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
 171                N_("edit message before committing"),
 172                PARSE_OPT_NOARG),
 173        OPT_CLEANUP(&cleanup_arg),
 174        OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
 175                N_("allow fast-forward"),
 176                PARSE_OPT_NOARG),
 177        OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
 178                N_("abort if fast-forward is not possible"),
 179                PARSE_OPT_NOARG | PARSE_OPT_NONEG),
 180        OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
 181                N_("verify that the named commit has a valid GPG signature"),
 182                PARSE_OPT_NOARG),
 183        OPT_BOOL(0, "autostash", &opt_autostash,
 184                N_("automatically stash/stash pop before and after rebase")),
 185        OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
 186                N_("merge strategy to use"),
 187                0),
 188        OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
 189                N_("option=value"),
 190                N_("option for selected merge strategy"),
 191                0),
 192        OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
 193                N_("GPG sign commit"),
 194                PARSE_OPT_OPTARG),
 195        OPT_SET_INT(0, "allow-unrelated-histories",
 196                    &opt_allow_unrelated_histories,
 197                    N_("allow merging unrelated histories"), 1),
 198
 199        /* Options passed to git-fetch */
 200        OPT_GROUP(N_("Options related to fetching")),
 201        OPT_PASSTHRU(0, "all", &opt_all, NULL,
 202                N_("fetch from all remotes"),
 203                PARSE_OPT_NOARG),
 204        OPT_PASSTHRU('a', "append", &opt_append, NULL,
 205                N_("append to .git/FETCH_HEAD instead of overwriting"),
 206                PARSE_OPT_NOARG),
 207        OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
 208                N_("path to upload pack on remote end"),
 209                0),
 210        OPT__FORCE(&opt_force, N_("force overwrite of local branch"), 0),
 211        OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
 212                N_("fetch all tags and associated objects"),
 213                PARSE_OPT_NOARG),
 214        OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
 215                N_("prune remote-tracking branches no longer on remote"),
 216                PARSE_OPT_NOARG),
 217        OPT_PASSTHRU('j', "jobs", &max_children, N_("n"),
 218                N_("number of submodules pulled in parallel"),
 219                PARSE_OPT_OPTARG),
 220        OPT_BOOL(0, "dry-run", &opt_dry_run,
 221                N_("dry run")),
 222        OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
 223                N_("keep downloaded pack"),
 224                PARSE_OPT_NOARG),
 225        OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
 226                N_("deepen history of shallow clone"),
 227                0),
 228        OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
 229                N_("convert to a complete repository"),
 230                PARSE_OPT_NONEG | PARSE_OPT_NOARG),
 231        OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
 232                N_("accept refs that update .git/shallow"),
 233                PARSE_OPT_NOARG),
 234        OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
 235                N_("specify fetch refmap"),
 236                PARSE_OPT_NONEG),
 237        OPT_PASSTHRU('4',  "ipv4", &opt_ipv4, NULL,
 238                N_("use IPv4 addresses only"),
 239                PARSE_OPT_NOARG),
 240        OPT_PASSTHRU('6',  "ipv6", &opt_ipv6, NULL,
 241                N_("use IPv6 addresses only"),
 242                PARSE_OPT_NOARG),
 243
 244        OPT_END()
 245};
 246
 247/**
 248 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
 249 */
 250static void argv_push_verbosity(struct argv_array *arr)
 251{
 252        int verbosity;
 253
 254        for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
 255                argv_array_push(arr, "-v");
 256
 257        for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
 258                argv_array_push(arr, "-q");
 259}
 260
 261/**
 262 * Pushes "-f" switches into arr to match the opt_force level.
 263 */
 264static void argv_push_force(struct argv_array *arr)
 265{
 266        int force = opt_force;
 267        while (force-- > 0)
 268                argv_array_push(arr, "-f");
 269}
 270
 271/**
 272 * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv
 273 */
 274static void set_reflog_message(int argc, const char **argv)
 275{
 276        int i;
 277        struct strbuf msg = STRBUF_INIT;
 278
 279        for (i = 0; i < argc; i++) {
 280                if (i)
 281                        strbuf_addch(&msg, ' ');
 282                strbuf_addstr(&msg, argv[i]);
 283        }
 284
 285        setenv("GIT_REFLOG_ACTION", msg.buf, 0);
 286
 287        strbuf_release(&msg);
 288}
 289
 290/**
 291 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
 292 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
 293 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
 294 * error.
 295 */
 296static const char *config_get_ff(void)
 297{
 298        const char *value;
 299
 300        if (git_config_get_value("pull.ff", &value))
 301                return NULL;
 302
 303        switch (git_parse_maybe_bool(value)) {
 304        case 0:
 305                return "--no-ff";
 306        case 1:
 307                return "--ff";
 308        }
 309
 310        if (!strcmp(value, "only"))
 311                return "--ff-only";
 312
 313        die(_("Invalid value for pull.ff: %s"), value);
 314}
 315
 316/**
 317 * Returns the default configured value for --rebase. It first looks for the
 318 * value of "branch.$curr_branch.rebase", where $curr_branch is the current
 319 * branch, and if HEAD is detached or the configuration key does not exist,
 320 * looks for the value of "pull.rebase". If both configuration keys do not
 321 * exist, returns REBASE_FALSE.
 322 */
 323static enum rebase_type config_get_rebase(void)
 324{
 325        struct branch *curr_branch = branch_get("HEAD");
 326        const char *value;
 327
 328        if (curr_branch) {
 329                char *key = xstrfmt("branch.%s.rebase", curr_branch->name);
 330
 331                if (!git_config_get_value(key, &value)) {
 332                        enum rebase_type ret = parse_config_rebase(key, value, 1);
 333                        free(key);
 334                        return ret;
 335                }
 336
 337                free(key);
 338        }
 339
 340        if (!git_config_get_value("pull.rebase", &value))
 341                return parse_config_rebase("pull.rebase", value, 1);
 342
 343        return REBASE_FALSE;
 344}
 345
 346/**
 347 * Read config variables.
 348 */
 349static int git_pull_config(const char *var, const char *value, void *cb)
 350{
 351        if (!strcmp(var, "rebase.autostash")) {
 352                config_autostash = git_config_bool(var, value);
 353                return 0;
 354        } else if (!strcmp(var, "submodule.recurse")) {
 355                recurse_submodules = git_config_bool(var, value) ?
 356                        RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF;
 357                return 0;
 358        }
 359        return git_default_config(var, value, cb);
 360}
 361
 362/**
 363 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
 364 * into merge_heads.
 365 */
 366static void get_merge_heads(struct oid_array *merge_heads)
 367{
 368        const char *filename = git_path_fetch_head(the_repository);
 369        FILE *fp;
 370        struct strbuf sb = STRBUF_INIT;
 371        struct object_id oid;
 372
 373        fp = xfopen(filename, "r");
 374        while (strbuf_getline_lf(&sb, fp) != EOF) {
 375                const char *p;
 376                if (parse_oid_hex(sb.buf, &oid, &p))
 377                        continue;  /* invalid line: does not start with object ID */
 378                if (starts_with(p, "\tnot-for-merge\t"))
 379                        continue;  /* ref is not-for-merge */
 380                oid_array_append(merge_heads, &oid);
 381        }
 382        fclose(fp);
 383        strbuf_release(&sb);
 384}
 385
 386/**
 387 * Used by die_no_merge_candidates() as a for_each_remote() callback to
 388 * retrieve the name of the remote if the repository only has one remote.
 389 */
 390static int get_only_remote(struct remote *remote, void *cb_data)
 391{
 392        const char **remote_name = cb_data;
 393
 394        if (*remote_name)
 395                return -1;
 396
 397        *remote_name = remote->name;
 398        return 0;
 399}
 400
 401/**
 402 * Dies with the appropriate reason for why there are no merge candidates:
 403 *
 404 * 1. We fetched from a specific remote, and a refspec was given, but it ended
 405 *    up not fetching anything. This is usually because the user provided a
 406 *    wildcard refspec which had no matches on the remote end.
 407 *
 408 * 2. We fetched from a non-default remote, but didn't specify a branch to
 409 *    merge. We can't use the configured one because it applies to the default
 410 *    remote, thus the user must specify the branches to merge.
 411 *
 412 * 3. We fetched from the branch's or repo's default remote, but:
 413 *
 414 *    a. We are not on a branch, so there will never be a configured branch to
 415 *       merge with.
 416 *
 417 *    b. We are on a branch, but there is no configured branch to merge with.
 418 *
 419 * 4. We fetched from the branch's or repo's default remote, but the configured
 420 *    branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
 421 *    part of the configured fetch refspec.)
 422 */
 423static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
 424{
 425        struct branch *curr_branch = branch_get("HEAD");
 426        const char *remote = curr_branch ? curr_branch->remote_name : NULL;
 427
 428        if (*refspecs) {
 429                if (opt_rebase)
 430                        fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched."));
 431                else
 432                        fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
 433                fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
 434                                        "matches on the remote end."));
 435        } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
 436                fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
 437                        "a branch. Because this is not the default configured remote\n"
 438                        "for your current branch, you must specify a branch on the command line."),
 439                        repo);
 440        } else if (!curr_branch) {
 441                fprintf_ln(stderr, _("You are not currently on a branch."));
 442                if (opt_rebase)
 443                        fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
 444                else
 445                        fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
 446                fprintf_ln(stderr, _("See git-pull(1) for details."));
 447                fprintf(stderr, "\n");
 448                fprintf_ln(stderr, "    git pull %s %s", _("<remote>"), _("<branch>"));
 449                fprintf(stderr, "\n");
 450        } else if (!curr_branch->merge_nr) {
 451                const char *remote_name = NULL;
 452
 453                if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
 454                        remote_name = _("<remote>");
 455
 456                fprintf_ln(stderr, _("There is no tracking information for the current branch."));
 457                if (opt_rebase)
 458                        fprintf_ln(stderr, _("Please specify which branch you want to rebase against."));
 459                else
 460                        fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
 461                fprintf_ln(stderr, _("See git-pull(1) for details."));
 462                fprintf(stderr, "\n");
 463                fprintf_ln(stderr, "    git pull %s %s", _("<remote>"), _("<branch>"));
 464                fprintf(stderr, "\n");
 465                fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:"));
 466                fprintf(stderr, "\n");
 467                fprintf_ln(stderr, "    git branch --set-upstream-to=%s/%s %s\n",
 468                                remote_name, _("<branch>"), curr_branch->name);
 469        } else
 470                fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
 471                        "from the remote, but no such ref was fetched."),
 472                        *curr_branch->merge_name);
 473        exit(1);
 474}
 475
 476/**
 477 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
 478 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
 479 * is not provided in argv, it is set to NULL.
 480 */
 481static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
 482                const char ***refspecs)
 483{
 484        if (argc > 0) {
 485                *repo = *argv++;
 486                argc--;
 487        } else
 488                *repo = NULL;
 489        *refspecs = argv;
 490}
 491
 492/**
 493 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
 494 * repository and refspecs to fetch, or NULL if they are not provided.
 495 */
 496static int run_fetch(const char *repo, const char **refspecs)
 497{
 498        struct argv_array args = ARGV_ARRAY_INIT;
 499        int ret;
 500
 501        argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
 502
 503        /* Shared options */
 504        argv_push_verbosity(&args);
 505        if (opt_progress)
 506                argv_array_push(&args, opt_progress);
 507
 508        /* Options passed to git-fetch */
 509        if (opt_all)
 510                argv_array_push(&args, opt_all);
 511        if (opt_append)
 512                argv_array_push(&args, opt_append);
 513        if (opt_upload_pack)
 514                argv_array_push(&args, opt_upload_pack);
 515        argv_push_force(&args);
 516        if (opt_tags)
 517                argv_array_push(&args, opt_tags);
 518        if (opt_prune)
 519                argv_array_push(&args, opt_prune);
 520        if (recurse_submodules != RECURSE_SUBMODULES_DEFAULT)
 521                switch (recurse_submodules) {
 522                case RECURSE_SUBMODULES_ON:
 523                        argv_array_push(&args, "--recurse-submodules=on");
 524                        break;
 525                case RECURSE_SUBMODULES_OFF:
 526                        argv_array_push(&args, "--recurse-submodules=no");
 527                        break;
 528                case RECURSE_SUBMODULES_ON_DEMAND:
 529                        argv_array_push(&args, "--recurse-submodules=on-demand");
 530                        break;
 531                default:
 532                        BUG("submodule recursion option not understood");
 533                }
 534        if (max_children)
 535                argv_array_push(&args, max_children);
 536        if (opt_dry_run)
 537                argv_array_push(&args, "--dry-run");
 538        if (opt_keep)
 539                argv_array_push(&args, opt_keep);
 540        if (opt_depth)
 541                argv_array_push(&args, opt_depth);
 542        if (opt_unshallow)
 543                argv_array_push(&args, opt_unshallow);
 544        if (opt_update_shallow)
 545                argv_array_push(&args, opt_update_shallow);
 546        if (opt_refmap)
 547                argv_array_push(&args, opt_refmap);
 548        if (opt_ipv4)
 549                argv_array_push(&args, opt_ipv4);
 550        if (opt_ipv6)
 551                argv_array_push(&args, opt_ipv6);
 552
 553        if (repo) {
 554                argv_array_push(&args, repo);
 555                argv_array_pushv(&args, refspecs);
 556        } else if (*refspecs)
 557                BUG("refspecs without repo?");
 558        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 559        argv_array_clear(&args);
 560        return ret;
 561}
 562
 563/**
 564 * "Pulls into void" by branching off merge_head.
 565 */
 566static int pull_into_void(const struct object_id *merge_head,
 567                const struct object_id *curr_head)
 568{
 569        if (opt_verify_signatures) {
 570                struct commit *commit;
 571
 572                commit = lookup_commit(the_repository, merge_head);
 573                if (!commit)
 574                        die(_("unable to access commit %s"),
 575                            oid_to_hex(merge_head));
 576
 577                verify_merge_signature(commit, opt_verbosity);
 578        }
 579
 580        /*
 581         * Two-way merge: we treat the index as based on an empty tree,
 582         * and try to fast-forward to HEAD. This ensures we will not lose
 583         * index/worktree changes that the user already made on the unborn
 584         * branch.
 585         */
 586        if (checkout_fast_forward(the_repository,
 587                                  the_hash_algo->empty_tree,
 588                                  merge_head, 0))
 589                return 1;
 590
 591        if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR))
 592                return 1;
 593
 594        return 0;
 595}
 596
 597static int rebase_submodules(void)
 598{
 599        struct child_process cp = CHILD_PROCESS_INIT;
 600
 601        cp.git_cmd = 1;
 602        cp.no_stdin = 1;
 603        argv_array_pushl(&cp.args, "submodule", "update",
 604                                   "--recursive", "--rebase", NULL);
 605        argv_push_verbosity(&cp.args);
 606
 607        return run_command(&cp);
 608}
 609
 610static int update_submodules(void)
 611{
 612        struct child_process cp = CHILD_PROCESS_INIT;
 613
 614        cp.git_cmd = 1;
 615        cp.no_stdin = 1;
 616        argv_array_pushl(&cp.args, "submodule", "update",
 617                                   "--recursive", "--checkout", NULL);
 618        argv_push_verbosity(&cp.args);
 619
 620        return run_command(&cp);
 621}
 622
 623/**
 624 * Runs git-merge, returning its exit status.
 625 */
 626static int run_merge(void)
 627{
 628        int ret;
 629        struct argv_array args = ARGV_ARRAY_INIT;
 630
 631        argv_array_pushl(&args, "merge", NULL);
 632
 633        /* Shared options */
 634        argv_push_verbosity(&args);
 635        if (opt_progress)
 636                argv_array_push(&args, opt_progress);
 637
 638        /* Options passed to git-merge */
 639        if (opt_diffstat)
 640                argv_array_push(&args, opt_diffstat);
 641        if (opt_log)
 642                argv_array_push(&args, opt_log);
 643        if (opt_signoff)
 644                argv_array_push(&args, opt_signoff);
 645        if (opt_squash)
 646                argv_array_push(&args, opt_squash);
 647        if (opt_commit)
 648                argv_array_push(&args, opt_commit);
 649        if (opt_edit)
 650                argv_array_push(&args, opt_edit);
 651        if (cleanup_arg)
 652                argv_array_pushf(&args, "--cleanup=%s", cleanup_arg);
 653        if (opt_ff)
 654                argv_array_push(&args, opt_ff);
 655        if (opt_verify_signatures)
 656                argv_array_push(&args, opt_verify_signatures);
 657        argv_array_pushv(&args, opt_strategies.argv);
 658        argv_array_pushv(&args, opt_strategy_opts.argv);
 659        if (opt_gpg_sign)
 660                argv_array_push(&args, opt_gpg_sign);
 661        if (opt_allow_unrelated_histories > 0)
 662                argv_array_push(&args, "--allow-unrelated-histories");
 663
 664        argv_array_push(&args, "FETCH_HEAD");
 665        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 666        argv_array_clear(&args);
 667        return ret;
 668}
 669
 670/**
 671 * Returns remote's upstream branch for the current branch. If remote is NULL,
 672 * the current branch's configured default remote is used. Returns NULL if
 673 * `remote` does not name a valid remote, HEAD does not point to a branch,
 674 * remote is not the branch's configured remote or the branch does not have any
 675 * configured upstream branch.
 676 */
 677static const char *get_upstream_branch(const char *remote)
 678{
 679        struct remote *rm;
 680        struct branch *curr_branch;
 681        const char *curr_branch_remote;
 682
 683        rm = remote_get(remote);
 684        if (!rm)
 685                return NULL;
 686
 687        curr_branch = branch_get("HEAD");
 688        if (!curr_branch)
 689                return NULL;
 690
 691        curr_branch_remote = remote_for_branch(curr_branch, NULL);
 692        assert(curr_branch_remote);
 693
 694        if (strcmp(curr_branch_remote, rm->name))
 695                return NULL;
 696
 697        return branch_get_upstream(curr_branch, NULL);
 698}
 699
 700/**
 701 * Derives the remote-tracking branch from the remote and refspec.
 702 *
 703 * FIXME: The current implementation assumes the default mapping of
 704 * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>.
 705 */
 706static const char *get_tracking_branch(const char *remote, const char *refspec)
 707{
 708        struct refspec_item spec;
 709        const char *spec_src;
 710        const char *merge_branch;
 711
 712        refspec_item_init_or_die(&spec, refspec, REFSPEC_FETCH);
 713        spec_src = spec.src;
 714        if (!*spec_src || !strcmp(spec_src, "HEAD"))
 715                spec_src = "HEAD";
 716        else if (skip_prefix(spec_src, "heads/", &spec_src))
 717                ;
 718        else if (skip_prefix(spec_src, "refs/heads/", &spec_src))
 719                ;
 720        else if (starts_with(spec_src, "refs/") ||
 721                starts_with(spec_src, "tags/") ||
 722                starts_with(spec_src, "remotes/"))
 723                spec_src = "";
 724
 725        if (*spec_src) {
 726                if (!strcmp(remote, "."))
 727                        merge_branch = mkpath("refs/heads/%s", spec_src);
 728                else
 729                        merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src);
 730        } else
 731                merge_branch = NULL;
 732
 733        refspec_item_clear(&spec);
 734        return merge_branch;
 735}
 736
 737/**
 738 * Given the repo and refspecs, sets fork_point to the point at which the
 739 * current branch forked from its remote-tracking branch. Returns 0 on success,
 740 * -1 on failure.
 741 */
 742static int get_rebase_fork_point(struct object_id *fork_point, const char *repo,
 743                const char *refspec)
 744{
 745        int ret;
 746        struct branch *curr_branch;
 747        const char *remote_branch;
 748        struct child_process cp = CHILD_PROCESS_INIT;
 749        struct strbuf sb = STRBUF_INIT;
 750
 751        curr_branch = branch_get("HEAD");
 752        if (!curr_branch)
 753                return -1;
 754
 755        if (refspec)
 756                remote_branch = get_tracking_branch(repo, refspec);
 757        else
 758                remote_branch = get_upstream_branch(repo);
 759
 760        if (!remote_branch)
 761                return -1;
 762
 763        argv_array_pushl(&cp.args, "merge-base", "--fork-point",
 764                        remote_branch, curr_branch->name, NULL);
 765        cp.no_stdin = 1;
 766        cp.no_stderr = 1;
 767        cp.git_cmd = 1;
 768
 769        ret = capture_command(&cp, &sb, GIT_MAX_HEXSZ);
 770        if (ret)
 771                goto cleanup;
 772
 773        ret = get_oid_hex(sb.buf, fork_point);
 774        if (ret)
 775                goto cleanup;
 776
 777cleanup:
 778        strbuf_release(&sb);
 779        return ret ? -1 : 0;
 780}
 781
 782/**
 783 * Sets merge_base to the octopus merge base of curr_head, merge_head and
 784 * fork_point. Returns 0 if a merge base is found, 1 otherwise.
 785 */
 786static int get_octopus_merge_base(struct object_id *merge_base,
 787                const struct object_id *curr_head,
 788                const struct object_id *merge_head,
 789                const struct object_id *fork_point)
 790{
 791        struct commit_list *revs = NULL, *result;
 792
 793        commit_list_insert(lookup_commit_reference(the_repository, curr_head),
 794                           &revs);
 795        commit_list_insert(lookup_commit_reference(the_repository, merge_head),
 796                           &revs);
 797        if (!is_null_oid(fork_point))
 798                commit_list_insert(lookup_commit_reference(the_repository, fork_point),
 799                                   &revs);
 800
 801        result = get_octopus_merge_bases(revs);
 802        free_commit_list(revs);
 803        reduce_heads_replace(&result);
 804
 805        if (!result)
 806                return 1;
 807
 808        oidcpy(merge_base, &result->item->object.oid);
 809        free_commit_list(result);
 810        return 0;
 811}
 812
 813/**
 814 * Given the current HEAD oid, the merge head returned from git-fetch and the
 815 * fork point calculated by get_rebase_fork_point(), runs git-rebase with the
 816 * appropriate arguments and returns its exit status.
 817 */
 818static int run_rebase(const struct object_id *curr_head,
 819                const struct object_id *merge_head,
 820                const struct object_id *fork_point)
 821{
 822        int ret;
 823        struct object_id oct_merge_base;
 824        struct argv_array args = ARGV_ARRAY_INIT;
 825
 826        if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point))
 827                if (!is_null_oid(fork_point) && oideq(&oct_merge_base, fork_point))
 828                        fork_point = NULL;
 829
 830        argv_array_push(&args, "rebase");
 831
 832        /* Shared options */
 833        argv_push_verbosity(&args);
 834
 835        /* Options passed to git-rebase */
 836        if (opt_rebase == REBASE_MERGES)
 837                argv_array_push(&args, "--rebase-merges");
 838        else if (opt_rebase == REBASE_PRESERVE)
 839                argv_array_push(&args, "--preserve-merges");
 840        else if (opt_rebase == REBASE_INTERACTIVE)
 841                argv_array_push(&args, "--interactive");
 842        if (opt_diffstat)
 843                argv_array_push(&args, opt_diffstat);
 844        argv_array_pushv(&args, opt_strategies.argv);
 845        argv_array_pushv(&args, opt_strategy_opts.argv);
 846        if (opt_gpg_sign)
 847                argv_array_push(&args, opt_gpg_sign);
 848        if (opt_autostash == 0)
 849                argv_array_push(&args, "--no-autostash");
 850        else if (opt_autostash == 1)
 851                argv_array_push(&args, "--autostash");
 852        if (opt_verify_signatures &&
 853            !strcmp(opt_verify_signatures, "--verify-signatures"))
 854                warning(_("ignoring --verify-signatures for rebase"));
 855
 856        argv_array_push(&args, "--onto");
 857        argv_array_push(&args, oid_to_hex(merge_head));
 858
 859        if (fork_point && !is_null_oid(fork_point))
 860                argv_array_push(&args, oid_to_hex(fork_point));
 861        else
 862                argv_array_push(&args, oid_to_hex(merge_head));
 863
 864        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 865        argv_array_clear(&args);
 866        return ret;
 867}
 868
 869int cmd_pull(int argc, const char **argv, const char *prefix)
 870{
 871        const char *repo, **refspecs;
 872        struct oid_array merge_heads = OID_ARRAY_INIT;
 873        struct object_id orig_head, curr_head;
 874        struct object_id rebase_fork_point;
 875        int autostash;
 876
 877        if (!getenv("GIT_REFLOG_ACTION"))
 878                set_reflog_message(argc, argv);
 879
 880        git_config(git_pull_config, NULL);
 881
 882        argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 883
 884        if (cleanup_arg)
 885                /*
 886                 * this only checks the validity of cleanup_arg; we don't need
 887                 * a valid value for use_editor
 888                 */
 889                get_cleanup_mode(cleanup_arg, 0);
 890
 891        parse_repo_refspecs(argc, argv, &repo, &refspecs);
 892
 893        if (!opt_ff)
 894                opt_ff = xstrdup_or_null(config_get_ff());
 895
 896        if (opt_rebase < 0)
 897                opt_rebase = config_get_rebase();
 898
 899        if (read_cache_unmerged())
 900                die_resolve_conflict("pull");
 901
 902        if (file_exists(git_path_merge_head(the_repository)))
 903                die_conclude_merge();
 904
 905        if (get_oid("HEAD", &orig_head))
 906                oidclr(&orig_head);
 907
 908        if (!opt_rebase && opt_autostash != -1)
 909                die(_("--[no-]autostash option is only valid with --rebase."));
 910
 911        autostash = config_autostash;
 912        if (opt_rebase) {
 913                if (opt_autostash != -1)
 914                        autostash = opt_autostash;
 915
 916                if (is_null_oid(&orig_head) && !is_cache_unborn())
 917                        die(_("Updating an unborn branch with changes added to the index."));
 918
 919                if (!autostash)
 920                        require_clean_work_tree(the_repository,
 921                                N_("pull with rebase"),
 922                                _("please commit or stash them."), 1, 0);
 923
 924                if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs))
 925                        oidclr(&rebase_fork_point);
 926        }
 927
 928        if (run_fetch(repo, refspecs))
 929                return 1;
 930
 931        if (opt_dry_run)
 932                return 0;
 933
 934        if (get_oid("HEAD", &curr_head))
 935                oidclr(&curr_head);
 936
 937        if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) &&
 938                        !oideq(&orig_head, &curr_head)) {
 939                /*
 940                 * The fetch involved updating the current branch.
 941                 *
 942                 * The working tree and the index file are still based on
 943                 * orig_head commit, but we are merging into curr_head.
 944                 * Update the working tree to match curr_head.
 945                 */
 946
 947                warning(_("fetch updated the current branch head.\n"
 948                        "fast-forwarding your working tree from\n"
 949                        "commit %s."), oid_to_hex(&orig_head));
 950
 951                if (checkout_fast_forward(the_repository, &orig_head,
 952                                          &curr_head, 0))
 953                        die(_("Cannot fast-forward your working tree.\n"
 954                                "After making sure that you saved anything precious from\n"
 955                                "$ git diff %s\n"
 956                                "output, run\n"
 957                                "$ git reset --hard\n"
 958                                "to recover."), oid_to_hex(&orig_head));
 959        }
 960
 961        get_merge_heads(&merge_heads);
 962
 963        if (!merge_heads.nr)
 964                die_no_merge_candidates(repo, refspecs);
 965
 966        if (is_null_oid(&orig_head)) {
 967                if (merge_heads.nr > 1)
 968                        die(_("Cannot merge multiple branches into empty head."));
 969                return pull_into_void(merge_heads.oid, &curr_head);
 970        }
 971        if (opt_rebase && merge_heads.nr > 1)
 972                die(_("Cannot rebase onto multiple branches."));
 973
 974        if (opt_rebase) {
 975                int ret = 0;
 976                if ((recurse_submodules == RECURSE_SUBMODULES_ON ||
 977                     recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) &&
 978                    submodule_touches_in_range(the_repository, &rebase_fork_point, &curr_head))
 979                        die(_("cannot rebase with locally recorded submodule modifications"));
 980                if (!autostash) {
 981                        struct commit_list *list = NULL;
 982                        struct commit *merge_head, *head;
 983
 984                        head = lookup_commit_reference(the_repository,
 985                                                       &orig_head);
 986                        commit_list_insert(head, &list);
 987                        merge_head = lookup_commit_reference(the_repository,
 988                                                             &merge_heads.oid[0]);
 989                        if (is_descendant_of(merge_head, list)) {
 990                                /* we can fast-forward this without invoking rebase */
 991                                opt_ff = "--ff-only";
 992                                ret = run_merge();
 993                        }
 994                }
 995                ret = run_rebase(&curr_head, merge_heads.oid, &rebase_fork_point);
 996
 997                if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
 998                             recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
 999                        ret = rebase_submodules();
1000
1001                return ret;
1002        } else {
1003                int ret = run_merge();
1004                if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON ||
1005                             recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND))
1006                        ret = update_submodules();
1007                return ret;
1008        }
1009}