diff options
Diffstat (limited to 'builtin/pull.c')
| -rw-r--r-- | builtin/pull.c | 882 |
1 files changed, 882 insertions, 0 deletions
diff --git a/builtin/pull.c b/builtin/pull.c new file mode 100644 index 0000000000..722a83c51b --- /dev/null +++ b/builtin/pull.c @@ -0,0 +1,882 @@ +/* + * Builtin "git pull" + * + * Based on git-pull.sh by Junio C Hamano + * + * Fetch one or more remote refs and merge it/them into the current HEAD. + */ +#include "cache.h" +#include "builtin.h" +#include "parse-options.h" +#include "exec_cmd.h" +#include "run-command.h" +#include "sha1-array.h" +#include "remote.h" +#include "dir.h" +#include "refs.h" +#include "revision.h" +#include "lockfile.h" + +enum rebase_type { + REBASE_INVALID = -1, + REBASE_FALSE = 0, + REBASE_TRUE, + REBASE_PRESERVE +}; + +/** + * Parses the value of --rebase. If value is a false value, returns + * REBASE_FALSE. If value is a true value, returns REBASE_TRUE. If value is + * "preserve", returns REBASE_PRESERVE. If value is a invalid value, dies with + * a fatal error if fatal is true, otherwise returns REBASE_INVALID. + */ +static enum rebase_type parse_config_rebase(const char *key, const char *value, + int fatal) +{ + int v = git_config_maybe_bool("pull.rebase", value); + + if (!v) + return REBASE_FALSE; + else if (v > 0) + return REBASE_TRUE; + else if (!strcmp(value, "preserve")) + return REBASE_PRESERVE; + + if (fatal) + die(_("Invalid value for %s: %s"), key, value); + else + error(_("Invalid value for %s: %s"), key, value); + + return REBASE_INVALID; +} + +/** + * Callback for --rebase, which parses arg with parse_config_rebase(). + */ +static int parse_opt_rebase(const struct option *opt, const char *arg, int unset) +{ + enum rebase_type *value = opt->value; + + if (arg) + *value = parse_config_rebase("--rebase", arg, 0); + else + *value = unset ? REBASE_FALSE : REBASE_TRUE; + return *value == REBASE_INVALID ? -1 : 0; +} + +static const char * const pull_usage[] = { + N_("git pull [options] [<repository> [<refspec>...]]"), + NULL +}; + +/* Shared options */ +static int opt_verbosity; +static char *opt_progress; + +/* Options passed to git-merge or git-rebase */ +static enum rebase_type opt_rebase = -1; +static char *opt_diffstat; +static char *opt_log; +static char *opt_squash; +static char *opt_commit; +static char *opt_edit; +static char *opt_ff; +static char *opt_verify_signatures; +static struct argv_array opt_strategies = ARGV_ARRAY_INIT; +static struct argv_array opt_strategy_opts = ARGV_ARRAY_INIT; +static char *opt_gpg_sign; + +/* Options passed to git-fetch */ +static char *opt_all; +static char *opt_append; +static char *opt_upload_pack; +static int opt_force; +static char *opt_tags; +static char *opt_prune; +static char *opt_recurse_submodules; +static int opt_dry_run; +static char *opt_keep; +static char *opt_depth; +static char *opt_unshallow; +static char *opt_update_shallow; +static char *opt_refmap; + +static struct option pull_options[] = { + /* Shared options */ + OPT__VERBOSITY(&opt_verbosity), + OPT_PASSTHRU(0, "progress", &opt_progress, NULL, + N_("force progress reporting"), + PARSE_OPT_NOARG), + + /* Options passed to git-merge or git-rebase */ + OPT_GROUP(N_("Options related to merging")), + { OPTION_CALLBACK, 'r', "rebase", &opt_rebase, + N_("false|true|preserve"), + N_("incorporate changes by rebasing rather than merging"), + PARSE_OPT_OPTARG, parse_opt_rebase }, + OPT_PASSTHRU('n', NULL, &opt_diffstat, NULL, + N_("do not show a diffstat at the end of the merge"), + PARSE_OPT_NOARG | PARSE_OPT_NONEG), + OPT_PASSTHRU(0, "stat", &opt_diffstat, NULL, + N_("show a diffstat at the end of the merge"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "summary", &opt_diffstat, NULL, + N_("(synonym to --stat)"), + PARSE_OPT_NOARG | PARSE_OPT_HIDDEN), + OPT_PASSTHRU(0, "log", &opt_log, N_("n"), + N_("add (at most <n>) entries from shortlog to merge commit message"), + PARSE_OPT_OPTARG), + OPT_PASSTHRU(0, "squash", &opt_squash, NULL, + N_("create a single commit instead of doing a merge"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "commit", &opt_commit, NULL, + N_("perform a commit if the merge succeeds (default)"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "edit", &opt_edit, NULL, + N_("edit message before committing"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "ff", &opt_ff, NULL, + N_("allow fast-forward"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "ff-only", &opt_ff, NULL, + N_("abort if fast-forward is not possible"), + PARSE_OPT_NOARG | PARSE_OPT_NONEG), + OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL, + N_("verify that the named commit has a valid GPG signature"), + PARSE_OPT_NOARG), + OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"), + N_("merge strategy to use"), + 0), + OPT_PASSTHRU_ARGV('X', "strategy-option", &opt_strategy_opts, + N_("option=value"), + N_("option for selected merge strategy"), + 0), + OPT_PASSTHRU('S', "gpg-sign", &opt_gpg_sign, N_("key-id"), + N_("GPG sign commit"), + PARSE_OPT_OPTARG), + + /* Options passed to git-fetch */ + OPT_GROUP(N_("Options related to fetching")), + OPT_PASSTHRU(0, "all", &opt_all, NULL, + N_("fetch from all remotes"), + PARSE_OPT_NOARG), + OPT_PASSTHRU('a', "append", &opt_append, NULL, + N_("append to .git/FETCH_HEAD instead of overwriting"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "upload-pack", &opt_upload_pack, N_("path"), + N_("path to upload pack on remote end"), + 0), + OPT__FORCE(&opt_force, N_("force overwrite of local branch")), + OPT_PASSTHRU('t', "tags", &opt_tags, NULL, + N_("fetch all tags and associated objects"), + PARSE_OPT_NOARG), + OPT_PASSTHRU('p', "prune", &opt_prune, NULL, + N_("prune remote-tracking branches no longer on remote"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "recurse-submodules", &opt_recurse_submodules, + N_("on-demand"), + N_("control recursive fetching of submodules"), + PARSE_OPT_OPTARG), + OPT_BOOL(0, "dry-run", &opt_dry_run, + N_("dry run")), + OPT_PASSTHRU('k', "keep", &opt_keep, NULL, + N_("keep downloaded pack"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "depth", &opt_depth, N_("depth"), + N_("deepen history of shallow clone"), + 0), + OPT_PASSTHRU(0, "unshallow", &opt_unshallow, NULL, + N_("convert to a complete repository"), + PARSE_OPT_NONEG | PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "update-shallow", &opt_update_shallow, NULL, + N_("accept refs that update .git/shallow"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "refmap", &opt_refmap, N_("refmap"), + N_("specify fetch refmap"), + PARSE_OPT_NONEG), + + OPT_END() +}; + +/** + * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level. + */ +static void argv_push_verbosity(struct argv_array *arr) +{ + int verbosity; + + for (verbosity = opt_verbosity; verbosity > 0; verbosity--) + argv_array_push(arr, "-v"); + + for (verbosity = opt_verbosity; verbosity < 0; verbosity++) + argv_array_push(arr, "-q"); +} + +/** + * Pushes "-f" switches into arr to match the opt_force level. + */ +static void argv_push_force(struct argv_array *arr) +{ + int force = opt_force; + while (force-- > 0) + argv_array_push(arr, "-f"); +} + +/** + * Sets the GIT_REFLOG_ACTION environment variable to the concatenation of argv + */ +static void set_reflog_message(int argc, const char **argv) +{ + int i; + struct strbuf msg = STRBUF_INIT; + + for (i = 0; i < argc; i++) { + if (i) + strbuf_addch(&msg, ' '); + strbuf_addstr(&msg, argv[i]); + } + + setenv("GIT_REFLOG_ACTION", msg.buf, 0); + + strbuf_release(&msg); +} + +/** + * If pull.ff is unset, returns NULL. If pull.ff is "true", returns "--ff". If + * pull.ff is "false", returns "--no-ff". If pull.ff is "only", returns + * "--ff-only". Otherwise, if pull.ff is set to an invalid value, die with an + * error. + */ +static const char *config_get_ff(void) +{ + const char *value; + + if (git_config_get_value("pull.ff", &value)) + return NULL; + + switch (git_config_maybe_bool("pull.ff", value)) { + case 0: + return "--no-ff"; + case 1: + return "--ff"; + } + + if (!strcmp(value, "only")) + return "--ff-only"; + + die(_("Invalid value for pull.ff: %s"), value); +} + +/** + * Returns the default configured value for --rebase. It first looks for the + * value of "branch.$curr_branch.rebase", where $curr_branch is the current + * branch, and if HEAD is detached or the configuration key does not exist, + * looks for the value of "pull.rebase". If both configuration keys do not + * exist, returns REBASE_FALSE. + */ +static enum rebase_type config_get_rebase(void) +{ + struct branch *curr_branch = branch_get("HEAD"); + const char *value; + + if (curr_branch) { + char *key = xstrfmt("branch.%s.rebase", curr_branch->name); + + if (!git_config_get_value(key, &value)) { + enum rebase_type ret = parse_config_rebase(key, value, 1); + free(key); + return ret; + } + + free(key); + } + + if (!git_config_get_value("pull.rebase", &value)) + return parse_config_rebase("pull.rebase", value, 1); + + return REBASE_FALSE; +} + +/** + * Returns 1 if there are unstaged changes, 0 otherwise. + */ +static int has_unstaged_changes(const char *prefix) +{ + struct rev_info rev_info; + int result; + + init_revisions(&rev_info, prefix); + DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES); + DIFF_OPT_SET(&rev_info.diffopt, QUICK); + diff_setup_done(&rev_info.diffopt); + result = run_diff_files(&rev_info, 0); + return diff_result_code(&rev_info.diffopt, result); +} + +/** + * Returns 1 if there are uncommitted changes, 0 otherwise. + */ +static int has_uncommitted_changes(const char *prefix) +{ + struct rev_info rev_info; + int result; + + if (is_cache_unborn()) + return 0; + + init_revisions(&rev_info, prefix); + DIFF_OPT_SET(&rev_info.diffopt, IGNORE_SUBMODULES); + DIFF_OPT_SET(&rev_info.diffopt, QUICK); + add_head_to_pending(&rev_info); + diff_setup_done(&rev_info.diffopt); + result = run_diff_index(&rev_info, 1); + return diff_result_code(&rev_info.diffopt, result); +} + +/** + * If the work tree has unstaged or uncommitted changes, dies with the + * appropriate message. + */ +static void die_on_unclean_work_tree(const char *prefix) +{ + struct lock_file *lock_file = xcalloc(1, sizeof(*lock_file)); + int do_die = 0; + + hold_locked_index(lock_file, 0); + refresh_cache(REFRESH_QUIET); + update_index_if_able(&the_index, lock_file); + rollback_lock_file(lock_file); + + if (has_unstaged_changes(prefix)) { + error(_("Cannot pull with rebase: You have unstaged changes.")); + do_die = 1; + } + + if (has_uncommitted_changes(prefix)) { + if (do_die) + error(_("Additionally, your index contains uncommitted changes.")); + else + error(_("Cannot pull with rebase: Your index contains uncommitted changes.")); + do_die = 1; + } + + if (do_die) + exit(1); +} + +/** + * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge + * into merge_heads. + */ +static void get_merge_heads(struct sha1_array *merge_heads) +{ + const char *filename = git_path("FETCH_HEAD"); + FILE *fp; + struct strbuf sb = STRBUF_INIT; + unsigned char sha1[GIT_SHA1_RAWSZ]; + + if (!(fp = fopen(filename, "r"))) + die_errno(_("could not open '%s' for reading"), filename); + while (strbuf_getline(&sb, fp, '\n') != EOF) { + if (get_sha1_hex(sb.buf, sha1)) + continue; /* invalid line: does not start with SHA1 */ + if (starts_with(sb.buf + GIT_SHA1_HEXSZ, "\tnot-for-merge\t")) + continue; /* ref is not-for-merge */ + sha1_array_append(merge_heads, sha1); + } + fclose(fp); + strbuf_release(&sb); +} + +/** + * Used by die_no_merge_candidates() as a for_each_remote() callback to + * retrieve the name of the remote if the repository only has one remote. + */ +static int get_only_remote(struct remote *remote, void *cb_data) +{ + const char **remote_name = cb_data; + + if (*remote_name) + return -1; + + *remote_name = remote->name; + return 0; +} + +/** + * Dies with the appropriate reason for why there are no merge candidates: + * + * 1. We fetched from a specific remote, and a refspec was given, but it ended + * up not fetching anything. This is usually because the user provided a + * wildcard refspec which had no matches on the remote end. + * + * 2. We fetched from a non-default remote, but didn't specify a branch to + * merge. We can't use the configured one because it applies to the default + * remote, thus the user must specify the branches to merge. + * + * 3. We fetched from the branch's or repo's default remote, but: + * + * a. We are not on a branch, so there will never be a configured branch to + * merge with. + * + * b. We are on a branch, but there is no configured branch to merge with. + * + * 4. We fetched from the branch's or repo's default remote, but the configured + * branch to merge didn't get fetched. (Either it doesn't exist, or wasn't + * part of the configured fetch refspec.) + */ +static void NORETURN die_no_merge_candidates(const char *repo, const char **refspecs) +{ + struct branch *curr_branch = branch_get("HEAD"); + const char *remote = curr_branch ? curr_branch->remote_name : NULL; + + if (*refspecs) { + if (opt_rebase) + fprintf_ln(stderr, _("There is no candidate for rebasing against among the refs that you just fetched.")); + else + fprintf_ln(stderr, _("There are no candidates for merging among the refs that you just fetched.")); + fprintf_ln(stderr, _("Generally this means that you provided a wildcard refspec which had no\n" + "matches on the remote end.")); + } else if (repo && curr_branch && (!remote || strcmp(repo, remote))) { + fprintf_ln(stderr, _("You asked to pull from the remote '%s', but did not specify\n" + "a branch. Because this is not the default configured remote\n" + "for your current branch, you must specify a branch on the command line."), + repo); + } else if (!curr_branch) { + fprintf_ln(stderr, _("You are not currently on a branch.")); + if (opt_rebase) + fprintf_ln(stderr, _("Please specify which branch you want to rebase against.")); + else + fprintf_ln(stderr, _("Please specify which branch you want to merge with.")); + fprintf_ln(stderr, _("See git-pull(1) for details.")); + fprintf(stderr, "\n"); + fprintf_ln(stderr, " git pull <remote> <branch>"); + fprintf(stderr, "\n"); + } else if (!curr_branch->merge_nr) { + const char *remote_name = NULL; + + if (for_each_remote(get_only_remote, &remote_name) || !remote_name) + remote_name = "<remote>"; + + fprintf_ln(stderr, _("There is no tracking information for the current branch.")); + if (opt_rebase) + fprintf_ln(stderr, _("Please specify which branch you want to rebase against.")); + else + fprintf_ln(stderr, _("Please specify which branch you want to merge with.")); + fprintf_ln(stderr, _("See git-pull(1) for details.")); + fprintf(stderr, "\n"); + fprintf_ln(stderr, " git pull <remote> <branch>"); + fprintf(stderr, "\n"); + fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:\n" + "\n" + " git branch --set-upstream-to=%s/<branch> %s\n"), + remote_name, curr_branch->name); + } else + fprintf_ln(stderr, _("Your configuration specifies to merge with the ref '%s'\n" + "from the remote, but no such ref was fetched."), + *curr_branch->merge_name); + exit(1); +} + +/** + * Parses argv into [<repo> [<refspecs>...]], returning their values in `repo` + * as a string and `refspecs` as a null-terminated array of strings. If `repo` + * is not provided in argv, it is set to NULL. + */ +static void parse_repo_refspecs(int argc, const char **argv, const char **repo, + const char ***refspecs) +{ + if (argc > 0) { + *repo = *argv++; + argc--; + } else + *repo = NULL; + *refspecs = argv; +} + +/** + * Runs git-fetch, returning its exit status. `repo` and `refspecs` are the + * repository and refspecs to fetch, or NULL if they are not provided. + */ +static int run_fetch(const char *repo, const char **refspecs) +{ + struct argv_array args = ARGV_ARRAY_INIT; + int ret; + + argv_array_pushl(&args, "fetch", "--update-head-ok", NULL); + + /* Shared options */ + argv_push_verbosity(&args); + if (opt_progress) + argv_array_push(&args, opt_progress); + + /* Options passed to git-fetch */ + if (opt_all) + argv_array_push(&args, opt_all); + if (opt_append) + argv_array_push(&args, opt_append); + if (opt_upload_pack) + argv_array_push(&args, opt_upload_pack); + argv_push_force(&args); + if (opt_tags) + argv_array_push(&args, opt_tags); + if (opt_prune) + argv_array_push(&args, opt_prune); + if (opt_recurse_submodules) + argv_array_push(&args, opt_recurse_submodules); + if (opt_dry_run) + argv_array_push(&args, "--dry-run"); + if (opt_keep) + argv_array_push(&args, opt_keep); + if (opt_depth) + argv_array_push(&args, opt_depth); + if (opt_unshallow) + argv_array_push(&args, opt_unshallow); + if (opt_update_shallow) + argv_array_push(&args, opt_update_shallow); + if (opt_refmap) + argv_array_push(&args, opt_refmap); + + if (repo) { + argv_array_push(&args, repo); + argv_array_pushv(&args, refspecs); + } else if (*refspecs) + die("BUG: refspecs without repo?"); + ret = run_command_v_opt(args.argv, RUN_GIT_CMD); + argv_array_clear(&args); + return ret; +} + +/** + * "Pulls into void" by branching off merge_head. + */ +static int pull_into_void(const unsigned char *merge_head, + const unsigned char *curr_head) +{ + /* + * Two-way merge: we treat the index as based on an empty tree, + * and try to fast-forward to HEAD. This ensures we will not lose + * index/worktree changes that the user already made on the unborn + * branch. + */ + if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0)) + return 1; + + if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR)) + return 1; + + return 0; +} + +/** + * Runs git-merge, returning its exit status. + */ +static int run_merge(void) +{ + int ret; + struct argv_array args = ARGV_ARRAY_INIT; + + argv_array_pushl(&args, "merge", NULL); + + /* Shared options */ + argv_push_verbosity(&args); + if (opt_progress) + argv_array_push(&args, opt_progress); + + /* Options passed to git-merge */ + if (opt_diffstat) + argv_array_push(&args, opt_diffstat); + if (opt_log) + argv_array_push(&args, opt_log); + if (opt_squash) + argv_array_push(&args, opt_squash); + if (opt_commit) + argv_array_push(&args, opt_commit); + if (opt_edit) + argv_array_push(&args, opt_edit); + if (opt_ff) + argv_array_push(&args, opt_ff); + if (opt_verify_signatures) + argv_array_push(&args, opt_verify_signatures); + argv_array_pushv(&args, opt_strategies.argv); + argv_array_pushv(&args, opt_strategy_opts.argv); + if (opt_gpg_sign) + argv_array_push(&args, opt_gpg_sign); + + argv_array_push(&args, "FETCH_HEAD"); + ret = run_command_v_opt(args.argv, RUN_GIT_CMD); + argv_array_clear(&args); + return ret; +} + +/** + * Returns remote's upstream branch for the current branch. If remote is NULL, + * the current branch's configured default remote is used. Returns NULL if + * `remote` does not name a valid remote, HEAD does not point to a branch, + * remote is not the branch's configured remote or the branch does not have any + * configured upstream branch. + */ +static const char *get_upstream_branch(const char *remote) +{ + struct remote *rm; + struct branch *curr_branch; + const char *curr_branch_remote; + + rm = remote_get(remote); + if (!rm) + return NULL; + + curr_branch = branch_get("HEAD"); + if (!curr_branch) + return NULL; + + curr_branch_remote = remote_for_branch(curr_branch, NULL); + assert(curr_branch_remote); + + if (strcmp(curr_branch_remote, rm->name)) + return NULL; + + return branch_get_upstream(curr_branch, NULL); +} + +/** + * Derives the remote tracking branch from the remote and refspec. + * + * FIXME: The current implementation assumes the default mapping of + * refs/heads/<branch_name> to refs/remotes/<remote_name>/<branch_name>. + */ +static const char *get_tracking_branch(const char *remote, const char *refspec) +{ + struct refspec *spec; + const char *spec_src; + const char *merge_branch; + + spec = parse_fetch_refspec(1, &refspec); + spec_src = spec->src; + if (!*spec_src || !strcmp(spec_src, "HEAD")) + spec_src = "HEAD"; + else if (skip_prefix(spec_src, "heads/", &spec_src)) + ; + else if (skip_prefix(spec_src, "refs/heads/", &spec_src)) + ; + else if (starts_with(spec_src, "refs/") || + starts_with(spec_src, "tags/") || + starts_with(spec_src, "remotes/")) + spec_src = ""; + + if (*spec_src) { + if (!strcmp(remote, ".")) + merge_branch = mkpath("refs/heads/%s", spec_src); + else + merge_branch = mkpath("refs/remotes/%s/%s", remote, spec_src); + } else + merge_branch = NULL; + + free_refspec(1, spec); + return merge_branch; +} + +/** + * Given the repo and refspecs, sets fork_point to the point at which the + * current branch forked from its remote tracking branch. Returns 0 on success, + * -1 on failure. + */ +static int get_rebase_fork_point(unsigned char *fork_point, const char *repo, + const char *refspec) +{ + int ret; + struct branch *curr_branch; + const char *remote_branch; + struct child_process cp = CHILD_PROCESS_INIT; + struct strbuf sb = STRBUF_INIT; + + curr_branch = branch_get("HEAD"); + if (!curr_branch) + return -1; + + if (refspec) + remote_branch = get_tracking_branch(repo, refspec); + else + remote_branch = get_upstream_branch(repo); + + if (!remote_branch) + return -1; + + argv_array_pushl(&cp.args, "merge-base", "--fork-point", + remote_branch, curr_branch->name, NULL); + cp.no_stdin = 1; + cp.no_stderr = 1; + cp.git_cmd = 1; + + ret = capture_command(&cp, &sb, GIT_SHA1_HEXSZ); + if (ret) + goto cleanup; + + ret = get_sha1_hex(sb.buf, fork_point); + if (ret) + goto cleanup; + +cleanup: + strbuf_release(&sb); + return ret ? -1 : 0; +} + +/** + * Sets merge_base to the octopus merge base of curr_head, merge_head and + * fork_point. Returns 0 if a merge base is found, 1 otherwise. + */ +static int get_octopus_merge_base(unsigned char *merge_base, + const unsigned char *curr_head, + const unsigned char *merge_head, + const unsigned char *fork_point) +{ + struct commit_list *revs = NULL, *result; + + commit_list_insert(lookup_commit_reference(curr_head), &revs); + commit_list_insert(lookup_commit_reference(merge_head), &revs); + if (!is_null_sha1(fork_point)) + commit_list_insert(lookup_commit_reference(fork_point), &revs); + + result = reduce_heads(get_octopus_merge_bases(revs)); + free_commit_list(revs); + if (!result) + return 1; + + hashcpy(merge_base, result->item->object.sha1); + return 0; +} + +/** + * Given the current HEAD SHA1, the merge head returned from git-fetch and the + * fork point calculated by get_rebase_fork_point(), runs git-rebase with the + * appropriate arguments and returns its exit status. + */ +static int run_rebase(const unsigned char *curr_head, + const unsigned char *merge_head, + const unsigned char *fork_point) +{ + int ret; + unsigned char oct_merge_base[GIT_SHA1_RAWSZ]; + struct argv_array args = ARGV_ARRAY_INIT; + + if (!get_octopus_merge_base(oct_merge_base, curr_head, merge_head, fork_point)) + if (!is_null_sha1(fork_point) && !hashcmp(oct_merge_base, fork_point)) + fork_point = NULL; + + argv_array_push(&args, "rebase"); + + /* Shared options */ + argv_push_verbosity(&args); + + /* Options passed to git-rebase */ + if (opt_rebase == REBASE_PRESERVE) + argv_array_push(&args, "--preserve-merges"); + if (opt_diffstat) + argv_array_push(&args, opt_diffstat); + argv_array_pushv(&args, opt_strategies.argv); + argv_array_pushv(&args, opt_strategy_opts.argv); + if (opt_gpg_sign) + argv_array_push(&args, opt_gpg_sign); + + argv_array_push(&args, "--onto"); + argv_array_push(&args, sha1_to_hex(merge_head)); + + if (fork_point && !is_null_sha1(fork_point)) + argv_array_push(&args, sha1_to_hex(fork_point)); + else + argv_array_push(&args, sha1_to_hex(merge_head)); + + ret = run_command_v_opt(args.argv, RUN_GIT_CMD); + argv_array_clear(&args); + return ret; +} + +int cmd_pull(int argc, const char **argv, const char *prefix) +{ + const char *repo, **refspecs; + struct sha1_array merge_heads = SHA1_ARRAY_INIT; + unsigned char orig_head[GIT_SHA1_RAWSZ], curr_head[GIT_SHA1_RAWSZ]; + unsigned char rebase_fork_point[GIT_SHA1_RAWSZ]; + + if (!getenv("GIT_REFLOG_ACTION")) + set_reflog_message(argc, argv); + + argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0); + + parse_repo_refspecs(argc, argv, &repo, &refspecs); + + if (!opt_ff) + opt_ff = xstrdup_or_null(config_get_ff()); + + if (opt_rebase < 0) + opt_rebase = config_get_rebase(); + + git_config(git_default_config, NULL); + + if (read_cache_unmerged()) + die_resolve_conflict("Pull"); + + if (file_exists(git_path("MERGE_HEAD"))) + die_conclude_merge(); + + if (get_sha1("HEAD", orig_head)) + hashclr(orig_head); + + if (opt_rebase) { + if (is_null_sha1(orig_head) && !is_cache_unborn()) + die(_("Updating an unborn branch with changes added to the index.")); + + die_on_unclean_work_tree(prefix); + + if (get_rebase_fork_point(rebase_fork_point, repo, *refspecs)) + hashclr(rebase_fork_point); + } + + if (run_fetch(repo, refspecs)) + return 1; + + if (opt_dry_run) + return 0; + + if (get_sha1("HEAD", curr_head)) + hashclr(curr_head); + + if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) && + hashcmp(orig_head, curr_head)) { + /* + * The fetch involved updating the current branch. + * + * The working tree and the index file are still based on + * orig_head commit, but we are merging into curr_head. + * Update the working tree to match curr_head. + */ + + warning(_("fetch updated the current branch head.\n" + "fast-forwarding your working tree from\n" + "commit %s."), sha1_to_hex(orig_head)); + + if (checkout_fast_forward(orig_head, curr_head, 0)) + die(_("Cannot fast-forward your working tree.\n" + "After making sure that you saved anything precious from\n" + "$ git diff %s\n" + "output, run\n" + "$ git reset --hard\n" + "to recover."), sha1_to_hex(orig_head)); + } + + get_merge_heads(&merge_heads); + + if (!merge_heads.nr) + die_no_merge_candidates(repo, refspecs); + + if (is_null_sha1(orig_head)) { + if (merge_heads.nr > 1) + die(_("Cannot merge multiple branches into empty head.")); + return pull_into_void(*merge_heads.sha1, curr_head); + } else if (opt_rebase) { + if (merge_heads.nr > 1) + die(_("Cannot rebase onto multiple branches.")); + return run_rebase(curr_head, *merge_heads.sha1, rebase_fork_point); + } else + return run_merge(); +} |