110e71948148f51d29288daf040667f4db12f5d1
   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#include "cache.h"
   9#include "builtin.h"
  10#include "parse-options.h"
  11#include "exec_cmd.h"
  12#include "run-command.h"
  13#include "sha1-array.h"
  14#include "remote.h"
  15#include "dir.h"
  16
  17static const char * const pull_usage[] = {
  18        N_("git pull [options] [<repository> [<refspec>...]]"),
  19        NULL
  20};
  21
  22/* Shared options */
  23static int opt_verbosity;
  24static char *opt_progress;
  25
  26/* Options passed to git-merge */
  27static char *opt_diffstat;
  28static char *opt_log;
  29static char *opt_squash;
  30static char *opt_commit;
  31static char *opt_edit;
  32static char *opt_ff;
  33static char *opt_verify_signatures;
  34static struct argv_array opt_strategies = ARGV_ARRAY_INIT;
  35static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT;
  36static char *opt_gpg_sign;
  37
  38/* Options passed to git-fetch */
  39static char *opt_all;
  40static char *opt_append;
  41static char *opt_upload_pack;
  42static int opt_force;
  43static char *opt_tags;
  44static char *opt_prune;
  45static char *opt_recurse_submodules;
  46static int opt_dry_run;
  47static char *opt_keep;
  48static char *opt_depth;
  49static char *opt_unshallow;
  50static char *opt_update_shallow;
  51static char *opt_refmap;
  52
  53static struct option pull_options[] = {
  54        /* Shared options */
  55        OPT__VERBOSITY(&opt_verbosity),
  56        OPT_PASSTHRU(0, "progress", &opt_progress, NULL,
  57                N_("force progress reporting"),
  58                PARSE_OPT_NOARG),
  59
  60        /* Options passed to git-merge */
  61        OPT_GROUP(N_("Options related to merging")),
  62        OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL,
  63                N_("do not show a diffstat at the end of the merge"),
  64                PARSE_OPT_NOARG | PARSE_OPT_NONEG),
  65        OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL,
  66                N_("show a diffstat at the end of the merge"),
  67                PARSE_OPT_NOARG),
  68        OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL,
  69                N_("(synonym to --stat)"),
  70                PARSE_OPT_NOARG | PARSE_OPT_HIDDEN),
  71        OPT_PASSTHRU(0, "log", &opt_log, N_("n"),
  72                N_("add (at most <n>) entries from shortlog to merge commit message"),
  73                PARSE_OPT_OPTARG),
  74        OPT_PASSTHRU(0, "squash", &opt_squash, NULL,
  75                N_("create a single commit instead of doing a merge"),
  76                PARSE_OPT_NOARG),
  77        OPT_PASSTHRU(0, "commit", &opt_commit, NULL,
  78                N_("perform a commit if the merge succeeds (default)"),
  79                PARSE_OPT_NOARG),
  80        OPT_PASSTHRU(0, "edit", &opt_edit, NULL,
  81                N_("edit message before committing"),
  82                PARSE_OPT_NOARG),
  83        OPT_PASSTHRU(0, "ff", &opt_ff, NULL,
  84                N_("allow fast-forward"),
  85                PARSE_OPT_NOARG),
  86        OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL,
  87                N_("abort if fast-forward is not possible"),
  88                PARSE_OPT_NOARG | PARSE_OPT_NONEG),
  89        OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL,
  90                N_("verify that the named commit has a valid GPG signature"),
  91                PARSE_OPT_NOARG),
  92        OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
  93                N_("merge strategy to use"),
  94                0),
  95        OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts,
  96                N_("option=value"),
  97                N_("option for selected merge strategy"),
  98                0),
  99        OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"),
 100                N_("GPG sign commit"),
 101                PARSE_OPT_OPTARG),
 102
 103        /* Options passed to git-fetch */
 104        OPT_GROUP(N_("Options related to fetching")),
 105        OPT_PASSTHRU(0, "all", &opt_all, NULL,
 106                N_("fetch from all remotes"),
 107                PARSE_OPT_NOARG),
 108        OPT_PASSTHRU('a', "append", &opt_append, NULL,
 109                N_("append to .git/FETCH_HEAD instead of overwriting"),
 110                PARSE_OPT_NOARG),
 111        OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"),
 112                N_("path to upload pack on remote end"),
 113                0),
 114        OPT__FORCE(&opt_force, N_("force overwrite of local branch")),
 115        OPT_PASSTHRU('t', "tags", &opt_tags, NULL,
 116                N_("fetch all tags and associated objects"),
 117                PARSE_OPT_NOARG),
 118        OPT_PASSTHRU('p', "prune", &opt_prune, NULL,
 119                N_("prune remote-tracking branches no longer on remote"),
 120                PARSE_OPT_NOARG),
 121        OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules,
 122                N_("on-demand"),
 123                N_("control recursive fetching of submodules"),
 124                PARSE_OPT_OPTARG),
 125        OPT_BOOL(0, "dry-run", &opt_dry_run,
 126                N_("dry run")),
 127        OPT_PASSTHRU('k', "keep", &opt_keep, NULL,
 128                N_("keep downloaded pack"),
 129                PARSE_OPT_NOARG),
 130        OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"),
 131                N_("deepen history of shallow clone"),
 132                0),
 133        OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL,
 134                N_("convert to a complete repository"),
 135                PARSE_OPT_NONEG | PARSE_OPT_NOARG),
 136        OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL,
 137                N_("accept refs that update .git/shallow"),
 138                PARSE_OPT_NOARG),
 139        OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"),
 140                N_("specify fetch refmap"),
 141                PARSE_OPT_NONEG),
 142
 143        OPT_END()
 144};
 145
 146/**
 147 * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level.
 148 */
 149static void argv_push_verbosity(struct argv_array *arr)
 150{
 151        int verbosity;
 152
 153        for (verbosity = opt_verbosity; verbosity > 0; verbosity--)
 154                argv_array_push(arr, "-v");
 155
 156        for (verbosity = opt_verbosity; verbosity < 0; verbosity++)
 157                argv_array_push(arr, "-q");
 158}
 159
 160/**
 161 * Pushes "-f" switches into arr to match the opt_force level.
 162 */
 163static void argv_push_force(struct argv_array *arr)
 164{
 165        int force = opt_force;
 166        while (force-- > 0)
 167                argv_array_push(arr, "-f");
 168}
 169
 170/**
 171 * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If
 172 * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns
 173 * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an
 174 * error.
 175 */
 176static const char *config_get_ff(void)
 177{
 178        const char *value;
 179
 180        if (git_config_get_value("pull.ff", &value))
 181                return NULL;
 182
 183        switch (git_config_maybe_bool("pull.ff", value)) {
 184        case 0:
 185                return "--no-ff";
 186        case 1:
 187                return "--ff";
 188        }
 189
 190        if (!strcmp(value, "only"))
 191                return "--ff-only";
 192
 193        die(_("Invalid value for pull.ff: %s"), value);
 194}
 195
 196/**
 197 * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge
 198 * into merge_heads.
 199 */
 200static void get_merge_heads(struct sha1_array *merge_heads)
 201{
 202        const char *filename = git_path("FETCH_HEAD");
 203        FILE *fp;
 204        struct strbuf sb = STRBUF_INIT;
 205        unsigned char sha1[GIT_SHA1_RAWSZ];
 206
 207        if (!(fp = fopen(filename, "r")))
 208                die_errno(_("could not open '%s' for reading"), filename);
 209        while (strbuf_getline(&sb, fp, '\n') != EOF) {
 210                if (get_sha1_hex(sb.buf, sha1))
 211                        continue;  /* invalid line: does not start with SHA1 */
 212                if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t"))
 213                        continue;  /* ref is not-for-merge */
 214                sha1_array_append(merge_heads, sha1);
 215        }
 216        fclose(fp);
 217        strbuf_release(&sb);
 218}
 219
 220/**
 221 * Used by die_no_merge_candidates() as a for_each_remote() callback to
 222 * retrieve the name of the remote if the repository only has one remote.
 223 */
 224static int get_only_remote(struct remote *remote, void *cb_data)
 225{
 226        const char **remote_name = cb_data;
 227
 228        if (*remote_name)
 229                return -1;
 230
 231        *remote_name = remote->name;
 232        return 0;
 233}
 234
 235/**
 236 * Dies with the appropriate reason for why there are no merge candidates:
 237 *
 238 * 1. We fetched from a specific remote, and a refspec was given, but it ended
 239 *    up not fetching anything. This is usually because the user provided a
 240 *    wildcard refspec which had no matches on the remote end.
 241 *
 242 * 2. We fetched from a non-default remote, but didn't specify a branch to
 243 *    merge. We can't use the configured one because it applies to the default
 244 *    remote, thus the user must specify the branches to merge.
 245 *
 246 * 3. We fetched from the branch's or repo's default remote, but:
 247 *
 248 *    a. We are not on a branch, so there will never be a configured branch to
 249 *       merge with.
 250 *
 251 *    b. We are on a branch, but there is no configured branch to merge with.
 252 *
 253 * 4. We fetched from the branch's or repo's default remote, but the configured
 254 *    branch to merge didn't get fetched. (Either it doesn't exist, or wasn't
 255 *    part of the configured fetch refspec.)
 256 */
 257static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs)
 258{
 259        struct branch *curr_branch = branch_get("HEAD");
 260        const char *remote = curr_branch ? curr_branch->remote_name : NULL;
 261
 262        if (*refspecs) {
 263                fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched."));
 264                fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n"
 265                                        "matches on the remote end."));
 266        } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) {
 267                fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n"
 268                        "a branch. Because this is not the default configured remote\n"
 269                        "for your current branch, you must specify a branch on the command line."),
 270                        repo);
 271        } else if (!curr_branch) {
 272                fprintf_ln(stderr, _("You are not currently on a branch."));
 273                fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
 274                fprintf_ln(stderr, _("See git-pull(1) for details."));
 275                fprintf(stderr, "\n");
 276                fprintf_ln(stderr, "    git pull <remote> <branch>");
 277                fprintf(stderr, "\n");
 278        } else if (!curr_branch->merge_nr) {
 279                const char *remote_name = NULL;
 280
 281                if (for_each_remote(get_only_remote, &remote_name) || !remote_name)
 282                        remote_name = "<remote>";
 283
 284                fprintf_ln(stderr, _("There is no tracking information for the current branch."));
 285                fprintf_ln(stderr, _("Please specify which branch you want to merge with."));
 286                fprintf_ln(stderr, _("See git-pull(1) for details."));
 287                fprintf(stderr, "\n");
 288                fprintf_ln(stderr, "    git pull <remote> <branch>");
 289                fprintf(stderr, "\n");
 290                fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:\n"
 291                                "\n"
 292                                "    git branch --set-upstream-to=%s/<branch> %s\n"),
 293                                remote_name, curr_branch->name);
 294        } else
 295                fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n"
 296                        "from the remote, but no such ref was fetched."),
 297                        *curr_branch->merge_name);
 298        exit(1);
 299}
 300
 301/**
 302 * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo`
 303 * as a string and `refspecs` as a null-terminated array of strings. If `repo`
 304 * is not provided in argv, it is set to NULL.
 305 */
 306static void parse_repo_refspecs(int argc, const char **argv, const char **repo,
 307                const char ***refspecs)
 308{
 309        if (argc > 0) {
 310                *repo = *argv++;
 311                argc--;
 312        } else
 313                *repo = NULL;
 314        *refspecs = argv;
 315}
 316
 317/**
 318 * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the
 319 * repository and refspecs to fetch, or NULL if they are not provided.
 320 */
 321static int run_fetch(const char *repo, const char **refspecs)
 322{
 323        struct argv_array args = ARGV_ARRAY_INIT;
 324        int ret;
 325
 326        argv_array_pushl(&args, "fetch", "--update-head-ok", NULL);
 327
 328        /* Shared options */
 329        argv_push_verbosity(&args);
 330        if (opt_progress)
 331                argv_array_push(&args, opt_progress);
 332
 333        /* Options passed to git-fetch */
 334        if (opt_all)
 335                argv_array_push(&args, opt_all);
 336        if (opt_append)
 337                argv_array_push(&args, opt_append);
 338        if (opt_upload_pack)
 339                argv_array_push(&args, opt_upload_pack);
 340        argv_push_force(&args);
 341        if (opt_tags)
 342                argv_array_push(&args, opt_tags);
 343        if (opt_prune)
 344                argv_array_push(&args, opt_prune);
 345        if (opt_recurse_submodules)
 346                argv_array_push(&args, opt_recurse_submodules);
 347        if (opt_dry_run)
 348                argv_array_push(&args, "--dry-run");
 349        if (opt_keep)
 350                argv_array_push(&args, opt_keep);
 351        if (opt_depth)
 352                argv_array_push(&args, opt_depth);
 353        if (opt_unshallow)
 354                argv_array_push(&args, opt_unshallow);
 355        if (opt_update_shallow)
 356                argv_array_push(&args, opt_update_shallow);
 357        if (opt_refmap)
 358                argv_array_push(&args, opt_refmap);
 359
 360        if (repo) {
 361                argv_array_push(&args, repo);
 362                argv_array_pushv(&args, refspecs);
 363        } else if (*refspecs)
 364                die("BUG: refspecs without repo?");
 365        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 366        argv_array_clear(&args);
 367        return ret;
 368}
 369
 370/**
 371 * Runs git-merge, returning its exit status.
 372 */
 373static int run_merge(void)
 374{
 375        int ret;
 376        struct argv_array args = ARGV_ARRAY_INIT;
 377
 378        argv_array_pushl(&args, "merge", NULL);
 379
 380        /* Shared options */
 381        argv_push_verbosity(&args);
 382        if (opt_progress)
 383                argv_array_push(&args, opt_progress);
 384
 385        /* Options passed to git-merge */
 386        if (opt_diffstat)
 387                argv_array_push(&args, opt_diffstat);
 388        if (opt_log)
 389                argv_array_push(&args, opt_log);
 390        if (opt_squash)
 391                argv_array_push(&args, opt_squash);
 392        if (opt_commit)
 393                argv_array_push(&args, opt_commit);
 394        if (opt_edit)
 395                argv_array_push(&args, opt_edit);
 396        if (opt_ff)
 397                argv_array_push(&args, opt_ff);
 398        if (opt_verify_signatures)
 399                argv_array_push(&args, opt_verify_signatures);
 400        argv_array_pushv(&args, opt_strategies.argv);
 401        argv_array_pushv(&args, opt_strategy_opts.argv);
 402        if (opt_gpg_sign)
 403                argv_array_push(&args, opt_gpg_sign);
 404
 405        argv_array_push(&args, "FETCH_HEAD");
 406        ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
 407        argv_array_clear(&args);
 408        return ret;
 409}
 410
 411int cmd_pull(int argc, const char **argv, const char *prefix)
 412{
 413        const char *repo, **refspecs;
 414        struct sha1_array merge_heads = SHA1_ARRAY_INIT;
 415        unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ];
 416
 417        if (!getenv("_GIT_USE_BUILTIN_PULL")) {
 418                const char *path = mkpath("%s/git-pull", git_exec_path());
 419
 420                if (sane_execvp(path, (char **)argv) < 0)
 421                        die_errno("could not exec %s", path);
 422        }
 423
 424        argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0);
 425
 426        parse_repo_refspecs(argc, argv, &repo, &refspecs);
 427
 428        if (!opt_ff)
 429                opt_ff = xstrdup_or_null(config_get_ff());
 430
 431        git_config(git_default_config, NULL);
 432
 433        if (read_cache_unmerged())
 434                die_resolve_conflict("Pull");
 435
 436        if (file_exists(git_path("MERGE_HEAD")))
 437                die_conclude_merge();
 438
 439        if (get_sha1("HEAD", orig_head))
 440                hashclr(orig_head);
 441
 442        if (run_fetch(repo, refspecs))
 443                return 1;
 444
 445        if (opt_dry_run)
 446                return 0;
 447
 448        if (get_sha1("HEAD", curr_head))
 449                hashclr(curr_head);
 450
 451        if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
 452                        hashcmp(orig_head, curr_head)) {
 453                /*
 454                 * The fetch involved updating the current branch.
 455                 *
 456                 * The working tree and the index file are still based on
 457                 * orig_head commit, but we are merging into curr_head.
 458                 * Update the working tree to match curr_head.
 459                 */
 460
 461                warning(_("fetch updated the current branch head.\n"
 462                        "fast-forwarding your working tree from\n"
 463                        "commit %s."), sha1_to_hex(orig_head));
 464
 465                if (checkout_fast_forward(orig_head, curr_head, 0))
 466                        die(_("Cannot fast-forward your working tree.\n"
 467                                "After making sure that you saved anything precious from\n"
 468                                "$ git diff %s\n"
 469                                "output, run\n"
 470                                "$ git reset --hard\n"
 471                                "to recover."), sha1_to_hex(orig_head));
 472        }
 473
 474        get_merge_heads(&merge_heads);
 475
 476        if (!merge_heads.nr)
 477                die_no_merge_candidates(repo, refspecs);
 478
 479        return run_merge();
 480}