#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>...]]"),
static int opt_verbosity;
static char *opt_progress;
-/* Options passed to git-merge */
+/* 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 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),
N_("force progress reporting"),
PARSE_OPT_NOARG),
- /* Options passed to git-merge */
+ /* 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),
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()
};
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`
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);
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.
*/
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_USE_BUILTIN_PULL")) {
- const char *path = mkpath("%s/git-pull", git_exec_path());
-
- if (sane_execvp(path, (char **)argv) < 0)
- die_errno("could not exec %s", path);
- }
+ 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;
- return run_merge();
+ 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();
}