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-rw-r--r--builtin/pull.c1160
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diff --git a/builtin/pull.c b/builtin/pull.c
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--- /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;
+}