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Diffstat (limited to 'builtin/pull.c')
| -rw-r--r-- | builtin/pull.c | 1160 |
1 files changed, 1160 insertions, 0 deletions
diff --git a/builtin/pull.c b/builtin/pull.c new file mode 100644 index 0000000..be2b2c9 --- /dev/null +++ b/builtin/pull.c @@ -0,0 +1,1160 @@ +/* + * 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. + */ +#define USE_THE_INDEX_VARIABLE +#include "builtin.h" +#include "advice.h" +#include "config.h" +#include "gettext.h" +#include "hex.h" +#include "merge.h" +#include "object-name.h" +#include "parse-options.h" +#include "exec-cmd.h" +#include "run-command.h" +#include "oid-array.h" +#include "remote.h" +#include "dir.h" +#include "path.h" +#include "read-cache-ll.h" +#include "rebase.h" +#include "refs.h" +#include "refspec.h" +#include "revision.h" +#include "submodule.h" +#include "submodule-config.h" +#include "tempfile.h" +#include "lockfile.h" +#include "wt-status.h" +#include "commit-reach.h" +#include "sequencer.h" +#include "packfile.h" + +/** + * 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 + * "merges", returns REBASE_MERGES. 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) +{ + enum rebase_type v = rebase_parse_value(value); + if (v != REBASE_INVALID) + return v; + + 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; +static int recurse_submodules = RECURSE_SUBMODULES_DEFAULT; +static int recurse_submodules_cli = RECURSE_SUBMODULES_DEFAULT; + +/* 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_signoff; +static char *opt_squash; +static char *opt_commit; +static char *opt_edit; +static char *cleanup_arg; +static char *opt_ff; +static char *opt_verify_signatures; +static char *opt_verify; +static int opt_autostash = -1; +static int config_autostash; +static int check_trust_level = 1; +static struct strvec opt_strategies = STRVEC_INIT; +static struct strvec opt_strategy_opts = STRVEC_INIT; +static char *opt_gpg_sign; +static int opt_allow_unrelated_histories; + +/* 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 *max_children; +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 char *opt_ipv4; +static char *opt_ipv6; +static int opt_show_forced_updates = -1; +static char *set_upstream; +static struct strvec opt_fetch = STRVEC_INIT; + +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), + OPT_CALLBACK_F(0, "recurse-submodules", + &recurse_submodules_cli, N_("on-demand"), + N_("control for recursive fetching of submodules"), + PARSE_OPT_OPTARG, option_fetch_parse_recurse_submodules), + + /* Options passed to git-merge or git-rebase */ + OPT_GROUP(N_("Options related to merging")), + OPT_CALLBACK_F('r', "rebase", &opt_rebase, + "(false|true|merges|interactive)", + 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, "signoff", &opt_signoff, NULL, + N_("add a Signed-off-by trailer"), + 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_CLEANUP(&cleanup_arg), + 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", &opt_verify, NULL, + N_("control use of pre-merge-commit and commit-msg hooks"), + PARSE_OPT_NOARG), + OPT_PASSTHRU(0, "verify-signatures", &opt_verify_signatures, NULL, + N_("verify that the named commit has a valid GPG signature"), + PARSE_OPT_NOARG), + OPT_BOOL(0, "autostash", &opt_autostash, + N_("automatically stash/stash pop before and after")), + 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), + OPT_SET_INT(0, "allow-unrelated-histories", + &opt_allow_unrelated_histories, + N_("allow merging unrelated histories"), 1), + + /* 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"), 0), + 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('j', "jobs", &max_children, N_("n"), + N_("number of submodules pulled in parallel"), + 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_ARGV(0, "shallow-since", &opt_fetch, N_("time"), + N_("deepen history of shallow repository based on time"), + 0), + OPT_PASSTHRU_ARGV(0, "shallow-exclude", &opt_fetch, N_("revision"), + N_("deepen history of shallow clone, excluding rev"), + 0), + OPT_PASSTHRU_ARGV(0, "deepen", &opt_fetch, N_("n"), + 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_PASSTHRU_ARGV('o', "server-option", &opt_fetch, + N_("server-specific"), + N_("option to transmit"), + 0), + OPT_PASSTHRU('4', "ipv4", &opt_ipv4, NULL, + N_("use IPv4 addresses only"), + PARSE_OPT_NOARG), + OPT_PASSTHRU('6', "ipv6", &opt_ipv6, NULL, + N_("use IPv6 addresses only"), + PARSE_OPT_NOARG), + OPT_PASSTHRU_ARGV(0, "negotiation-tip", &opt_fetch, N_("revision"), + N_("report that we have only objects reachable from this object"), + 0), + OPT_BOOL(0, "show-forced-updates", &opt_show_forced_updates, + N_("check for forced-updates on all updated branches")), + OPT_PASSTHRU(0, "set-upstream", &set_upstream, NULL, + N_("set upstream for git pull/fetch"), + PARSE_OPT_NOARG), + + OPT_END() +}; + +/** + * Pushes "-q" or "-v" switches into arr to match the opt_verbosity level. + */ +static void argv_push_verbosity(struct strvec *arr) +{ + int verbosity; + + for (verbosity = opt_verbosity; verbosity > 0; verbosity--) + strvec_push(arr, "-v"); + + for (verbosity = opt_verbosity; verbosity < 0; verbosity++) + strvec_push(arr, "-q"); +} + +/** + * Pushes "-f" switches into arr to match the opt_force level. + */ +static void argv_push_force(struct strvec *arr) +{ + int force = opt_force; + while (force-- > 0) + strvec_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_parse_maybe_bool(value)) { + case 0: + return "--no-ff"; + case 1: + return "--ff"; + } + + if (!strcmp(value, "only")) + return "--ff-only"; + + die(_("invalid value for '%s': '%s'"), "pull.ff", 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(int *rebase_unspecified) +{ + 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); + + *rebase_unspecified = 1; + + return REBASE_FALSE; +} + +/** + * Read config variables. + */ +static int git_pull_config(const char *var, const char *value, + const struct config_context *ctx, void *cb) +{ + if (!strcmp(var, "rebase.autostash")) { + config_autostash = git_config_bool(var, value); + return 0; + } else if (!strcmp(var, "submodule.recurse")) { + recurse_submodules = git_config_bool(var, value) ? + RECURSE_SUBMODULES_ON : RECURSE_SUBMODULES_OFF; + return 0; + } else if (!strcmp(var, "gpg.mintrustlevel")) { + check_trust_level = 0; + } + + return git_default_config(var, value, ctx, cb); +} + +/** + * Appends merge candidates from FETCH_HEAD that are not marked not-for-merge + * into merge_heads. + */ +static void get_merge_heads(struct oid_array *merge_heads) +{ + const char *filename = git_path_fetch_head(the_repository); + FILE *fp; + struct strbuf sb = STRBUF_INIT; + struct object_id oid; + + fp = xfopen(filename, "r"); + while (strbuf_getline_lf(&sb, fp) != EOF) { + const char *p; + if (parse_oid_hex(sb.buf, &oid, &p)) + continue; /* invalid line: does not start with object ID */ + if (starts_with(p, "\tnot-for-merge\t")) + continue; /* ref is not-for-merge */ + oid_array_append(merge_heads, &oid); + } + 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 %s %s", _("<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 %s %s", _("<remote>"), _("<branch>")); + fprintf(stderr, "\n"); + fprintf_ln(stderr, _("If you wish to set tracking information for this branch you can do so with:")); + fprintf(stderr, "\n"); + fprintf_ln(stderr, " git branch --set-upstream-to=%s/%s %s\n", + remote_name, _("<branch>"), 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 child_process cmd = CHILD_PROCESS_INIT; + + strvec_pushl(&cmd.args, "fetch", "--update-head-ok", NULL); + + /* Shared options */ + argv_push_verbosity(&cmd.args); + if (opt_progress) + strvec_push(&cmd.args, opt_progress); + + /* Options passed to git-fetch */ + if (opt_all) + strvec_push(&cmd.args, opt_all); + if (opt_append) + strvec_push(&cmd.args, opt_append); + if (opt_upload_pack) + strvec_push(&cmd.args, opt_upload_pack); + argv_push_force(&cmd.args); + if (opt_tags) + strvec_push(&cmd.args, opt_tags); + if (opt_prune) + strvec_push(&cmd.args, opt_prune); + if (recurse_submodules_cli != RECURSE_SUBMODULES_DEFAULT) + switch (recurse_submodules_cli) { + case RECURSE_SUBMODULES_ON: + strvec_push(&cmd.args, "--recurse-submodules=on"); + break; + case RECURSE_SUBMODULES_OFF: + strvec_push(&cmd.args, "--recurse-submodules=no"); + break; + case RECURSE_SUBMODULES_ON_DEMAND: + strvec_push(&cmd.args, "--recurse-submodules=on-demand"); + break; + default: + BUG("submodule recursion option not understood"); + } + if (max_children) + strvec_push(&cmd.args, max_children); + if (opt_dry_run) + strvec_push(&cmd.args, "--dry-run"); + if (opt_keep) + strvec_push(&cmd.args, opt_keep); + if (opt_depth) + strvec_push(&cmd.args, opt_depth); + if (opt_unshallow) + strvec_push(&cmd.args, opt_unshallow); + if (opt_update_shallow) + strvec_push(&cmd.args, opt_update_shallow); + if (opt_refmap) + strvec_push(&cmd.args, opt_refmap); + if (opt_ipv4) + strvec_push(&cmd.args, opt_ipv4); + if (opt_ipv6) + strvec_push(&cmd.args, opt_ipv6); + if (opt_show_forced_updates > 0) + strvec_push(&cmd.args, "--show-forced-updates"); + else if (opt_show_forced_updates == 0) + strvec_push(&cmd.args, "--no-show-forced-updates"); + if (set_upstream) + strvec_push(&cmd.args, set_upstream); + strvec_pushv(&cmd.args, opt_fetch.v); + + if (repo) { + strvec_push(&cmd.args, repo); + strvec_pushv(&cmd.args, refspecs); + } else if (*refspecs) + BUG("refspecs without repo?"); + cmd.git_cmd = 1; + cmd.close_object_store = 1; + return run_command(&cmd); +} + +/** + * "Pulls into void" by branching off merge_head. + */ +static int pull_into_void(const struct object_id *merge_head, + const struct object_id *curr_head) +{ + if (opt_verify_signatures) { + struct commit *commit; + + commit = lookup_commit(the_repository, merge_head); + if (!commit) + die(_("unable to access commit %s"), + oid_to_hex(merge_head)); + + verify_merge_signature(commit, opt_verbosity, + check_trust_level); + } + + /* + * 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(the_repository, + the_hash_algo->empty_tree, + 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; +} + +static int rebase_submodules(void) +{ + struct child_process cp = CHILD_PROCESS_INIT; + + cp.git_cmd = 1; + cp.no_stdin = 1; + strvec_pushl(&cp.args, "submodule", "update", + "--recursive", "--rebase", NULL); + argv_push_verbosity(&cp.args); + + return run_command(&cp); +} + +static int update_submodules(void) +{ + struct child_process cp = CHILD_PROCESS_INIT; + + cp.git_cmd = 1; + cp.no_stdin = 1; + strvec_pushl(&cp.args, "submodule", "update", + "--recursive", "--checkout", NULL); + argv_push_verbosity(&cp.args); + + return run_command(&cp); +} + +/** + * Runs git-merge, returning its exit status. + */ +static int run_merge(void) +{ + struct child_process cmd = CHILD_PROCESS_INIT; + + strvec_pushl(&cmd.args, "merge", NULL); + + /* Shared options */ + argv_push_verbosity(&cmd.args); + if (opt_progress) + strvec_push(&cmd.args, opt_progress); + + /* Options passed to git-merge */ + if (opt_diffstat) + strvec_push(&cmd.args, opt_diffstat); + if (opt_log) + strvec_push(&cmd.args, opt_log); + if (opt_signoff) + strvec_push(&cmd.args, opt_signoff); + if (opt_squash) + strvec_push(&cmd.args, opt_squash); + if (opt_commit) + strvec_push(&cmd.args, opt_commit); + if (opt_edit) + strvec_push(&cmd.args, opt_edit); + if (cleanup_arg) + strvec_pushf(&cmd.args, "--cleanup=%s", cleanup_arg); + if (opt_ff) + strvec_push(&cmd.args, opt_ff); + if (opt_verify) + strvec_push(&cmd.args, opt_verify); + if (opt_verify_signatures) + strvec_push(&cmd.args, opt_verify_signatures); + strvec_pushv(&cmd.args, opt_strategies.v); + strvec_pushv(&cmd.args, opt_strategy_opts.v); + if (opt_gpg_sign) + strvec_push(&cmd.args, opt_gpg_sign); + if (opt_autostash == 0) + strvec_push(&cmd.args, "--no-autostash"); + else if (opt_autostash == 1) + strvec_push(&cmd.args, "--autostash"); + if (opt_allow_unrelated_histories > 0) + strvec_push(&cmd.args, "--allow-unrelated-histories"); + + strvec_push(&cmd.args, "FETCH_HEAD"); + cmd.git_cmd = 1; + return run_command(&cmd); +} + +/** + * 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_item spec; + const char *spec_src; + const char *merge_branch; + + refspec_item_init_or_die(&spec, refspec, REFSPEC_FETCH); + 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; + + refspec_item_clear(&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(struct object_id *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; + + strvec_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_MAX_HEXSZ); + if (ret) + goto cleanup; + + ret = get_oid_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(struct object_id *merge_base, + const struct object_id *curr_head, + const struct object_id *merge_head, + const struct object_id *fork_point) +{ + struct commit_list *revs = NULL, *result; + + commit_list_insert(lookup_commit_reference(the_repository, curr_head), + &revs); + commit_list_insert(lookup_commit_reference(the_repository, merge_head), + &revs); + if (!is_null_oid(fork_point)) + commit_list_insert(lookup_commit_reference(the_repository, fork_point), + &revs); + + result = get_octopus_merge_bases(revs); + free_commit_list(revs); + reduce_heads_replace(&result); + + if (!result) + return 1; + + oidcpy(merge_base, &result->item->object.oid); + free_commit_list(result); + return 0; +} + +/** + * Given the current HEAD oid, the merge head returned from git-fetch and the + * fork point calculated by get_rebase_fork_point(), compute the <newbase> and + * <upstream> arguments to use for the upcoming git-rebase invocation. + */ +static int get_rebase_newbase_and_upstream(struct object_id *newbase, + struct object_id *upstream, + const struct object_id *curr_head, + const struct object_id *merge_head, + const struct object_id *fork_point) +{ + struct object_id oct_merge_base; + + if (!get_octopus_merge_base(&oct_merge_base, curr_head, merge_head, fork_point)) + if (!is_null_oid(fork_point) && oideq(&oct_merge_base, fork_point)) + fork_point = NULL; + + if (fork_point && !is_null_oid(fork_point)) + oidcpy(upstream, fork_point); + else + oidcpy(upstream, merge_head); + + oidcpy(newbase, merge_head); + + return 0; +} + +/** + * Given the <newbase> and <upstream> calculated by + * get_rebase_newbase_and_upstream(), runs git-rebase with the + * appropriate arguments and returns its exit status. + */ +static int run_rebase(const struct object_id *newbase, + const struct object_id *upstream) +{ + struct child_process cmd = CHILD_PROCESS_INIT; + + strvec_push(&cmd.args, "rebase"); + + /* Shared options */ + argv_push_verbosity(&cmd.args); + + /* Options passed to git-rebase */ + if (opt_rebase == REBASE_MERGES) + strvec_push(&cmd.args, "--rebase-merges"); + else if (opt_rebase == REBASE_INTERACTIVE) + strvec_push(&cmd.args, "--interactive"); + if (opt_diffstat) + strvec_push(&cmd.args, opt_diffstat); + strvec_pushv(&cmd.args, opt_strategies.v); + strvec_pushv(&cmd.args, opt_strategy_opts.v); + if (opt_gpg_sign) + strvec_push(&cmd.args, opt_gpg_sign); + if (opt_signoff) + strvec_push(&cmd.args, opt_signoff); + if (opt_autostash == 0) + strvec_push(&cmd.args, "--no-autostash"); + else if (opt_autostash == 1) + strvec_push(&cmd.args, "--autostash"); + if (opt_verify_signatures && + !strcmp(opt_verify_signatures, "--verify-signatures")) + warning(_("ignoring --verify-signatures for rebase")); + + strvec_push(&cmd.args, "--onto"); + strvec_push(&cmd.args, oid_to_hex(newbase)); + + strvec_push(&cmd.args, oid_to_hex(upstream)); + + cmd.git_cmd = 1; + return run_command(&cmd); +} + +static int get_can_ff(struct object_id *orig_head, + struct oid_array *merge_heads) +{ + int ret; + struct commit_list *list = NULL; + struct commit *merge_head, *head; + struct object_id *orig_merge_head; + + if (merge_heads->nr > 1) + return 0; + + orig_merge_head = &merge_heads->oid[0]; + head = lookup_commit_reference(the_repository, orig_head); + commit_list_insert(head, &list); + merge_head = lookup_commit_reference(the_repository, orig_merge_head); + ret = repo_is_descendant_of(the_repository, merge_head, list); + free_commit_list(list); + return ret; +} + +/* + * Is orig_head a descendant of _all_ merge_heads? + * Unfortunately is_descendant_of() cannot be used as it asks + * if orig_head is a descendant of at least one of them. + */ +static int already_up_to_date(struct object_id *orig_head, + struct oid_array *merge_heads) +{ + int i; + struct commit *ours; + + ours = lookup_commit_reference(the_repository, orig_head); + for (i = 0; i < merge_heads->nr; i++) { + struct commit_list *list = NULL; + struct commit *theirs; + int ok; + + theirs = lookup_commit_reference(the_repository, &merge_heads->oid[i]); + commit_list_insert(theirs, &list); + ok = repo_is_descendant_of(the_repository, ours, list); + free_commit_list(list); + if (!ok) + return 0; + } + return 1; +} + +static void show_advice_pull_non_ff(void) +{ + advise(_("You have divergent branches and need to specify how to reconcile them.\n" + "You can do so by running one of the following commands sometime before\n" + "your next pull:\n" + "\n" + " git config pull.rebase false # merge\n" + " git config pull.rebase true # rebase\n" + " git config pull.ff only # fast-forward only\n" + "\n" + "You can replace \"git config\" with \"git config --global\" to set a default\n" + "preference for all repositories. You can also pass --rebase, --no-rebase,\n" + "or --ff-only on the command line to override the configured default per\n" + "invocation.\n")); +} + +int cmd_pull(int argc, const char **argv, const char *prefix) +{ + const char *repo, **refspecs; + struct oid_array merge_heads = OID_ARRAY_INIT; + struct object_id orig_head, curr_head; + struct object_id rebase_fork_point; + int rebase_unspecified = 0; + int can_ff; + int divergent; + int ret; + + if (!getenv("GIT_REFLOG_ACTION")) + set_reflog_message(argc, argv); + + git_config(git_pull_config, NULL); + if (the_repository->gitdir) { + prepare_repo_settings(the_repository); + the_repository->settings.command_requires_full_index = 0; + } + + argc = parse_options(argc, argv, prefix, pull_options, pull_usage, 0); + + if (recurse_submodules_cli != RECURSE_SUBMODULES_DEFAULT) + recurse_submodules = recurse_submodules_cli; + + if (cleanup_arg) + /* + * this only checks the validity of cleanup_arg; we don't need + * a valid value for use_editor + */ + get_cleanup_mode(cleanup_arg, 0); + + parse_repo_refspecs(argc, argv, &repo, &refspecs); + + if (!opt_ff) { + opt_ff = xstrdup_or_null(config_get_ff()); + /* + * A subtle point: opt_ff was set on the line above via + * reading from config. opt_rebase, in contrast, is set + * before this point via command line options. The setting + * of opt_rebase via reading from config (using + * config_get_rebase()) does not happen until later. We + * are relying on the next if-condition happening before + * the config_get_rebase() call so that an explicit + * "--rebase" can override a config setting of + * pull.ff=only. + */ + if (opt_rebase >= 0 && opt_ff && !strcmp(opt_ff, "--ff-only")) + opt_ff = "--ff"; + } + + if (opt_rebase < 0) + opt_rebase = config_get_rebase(&rebase_unspecified); + + if (repo_read_index_unmerged(the_repository)) + die_resolve_conflict("pull"); + + if (file_exists(git_path_merge_head(the_repository))) + die_conclude_merge(); + + if (repo_get_oid(the_repository, "HEAD", &orig_head)) + oidclr(&orig_head); + + if (opt_rebase) { + if (opt_autostash == -1) + opt_autostash = config_autostash; + + if (is_null_oid(&orig_head) && !is_index_unborn(&the_index)) + die(_("Updating an unborn branch with changes added to the index.")); + + if (!opt_autostash) + require_clean_work_tree(the_repository, + N_("pull with rebase"), + _("Please commit or stash them."), 1, 0); + + if (get_rebase_fork_point(&rebase_fork_point, repo, *refspecs)) + oidclr(&rebase_fork_point); + } + + if (run_fetch(repo, refspecs)) + return 1; + + if (opt_dry_run) + return 0; + + if (repo_get_oid(the_repository, "HEAD", &curr_head)) + oidclr(&curr_head); + + if (!is_null_oid(&orig_head) && !is_null_oid(&curr_head) && + !oideq(&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."), oid_to_hex(&orig_head)); + + if (checkout_fast_forward(the_repository, &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."), oid_to_hex(&orig_head)); + } + + get_merge_heads(&merge_heads); + + if (!merge_heads.nr) + die_no_merge_candidates(repo, refspecs); + + if (is_null_oid(&orig_head)) { + if (merge_heads.nr > 1) + die(_("Cannot merge multiple branches into empty head.")); + ret = pull_into_void(merge_heads.oid, &curr_head); + goto cleanup; + } + if (merge_heads.nr > 1) { + if (opt_rebase) + die(_("Cannot rebase onto multiple branches.")); + if (opt_ff && !strcmp(opt_ff, "--ff-only")) + die(_("Cannot fast-forward to multiple branches.")); + } + + can_ff = get_can_ff(&orig_head, &merge_heads); + divergent = !can_ff && !already_up_to_date(&orig_head, &merge_heads); + + /* ff-only takes precedence over rebase */ + if (opt_ff && !strcmp(opt_ff, "--ff-only")) { + if (divergent) + die_ff_impossible(); + opt_rebase = REBASE_FALSE; + } + /* If no action specified and we can't fast forward, then warn. */ + if (!opt_ff && rebase_unspecified && divergent) { + show_advice_pull_non_ff(); + die(_("Need to specify how to reconcile divergent branches.")); + } + + if (opt_rebase) { + struct object_id newbase; + struct object_id upstream; + get_rebase_newbase_and_upstream(&newbase, &upstream, &curr_head, + merge_heads.oid, &rebase_fork_point); + + if ((recurse_submodules == RECURSE_SUBMODULES_ON || + recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND) && + submodule_touches_in_range(the_repository, &upstream, &curr_head)) + die(_("cannot rebase with locally recorded submodule modifications")); + + if (can_ff) { + /* we can fast-forward this without invoking rebase */ + opt_ff = "--ff-only"; + ret = run_merge(); + } else { + ret = run_rebase(&newbase, &upstream); + } + + if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON || + recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)) + ret = rebase_submodules(); + + goto cleanup; + } else { + ret = run_merge(); + if (!ret && (recurse_submodules == RECURSE_SUBMODULES_ON || + recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)) + ret = update_submodules(); + goto cleanup; + } + +cleanup: + oid_array_clear(&merge_heads); + return ret; +} |