#include "run-command.h"
#include "sha1-array.h"
#include "remote.h"
+#include "dir.h"
+#include "refs.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;
static char *opt_diffstat;
static char *opt_log;
static char *opt_squash;
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),
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
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());
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());
+ 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 (get_rebase_fork_point(rebase_fork_point, repo, *refspecs))
+ hashclr(rebase_fork_point);
+
if (run_fetch(repo, refspecs))
return 1;
if (opt_dry_run)
return 0;
+ if (get_sha1("HEAD", curr_head))
+ hashclr(curr_head);
+
+ if (!is_null_sha1(orig_head) && !is_null_sha1(curr_head) &&
+ hashcmp(orig_head, curr_head)) {
+ /*
+ * The fetch involved updating the current branch.
+ *
+ * The working tree and the index file are still based on
+ * orig_head commit, but we are merging into curr_head.
+ * Update the working tree to match curr_head.
+ */
+
+ warning(_("fetch updated the current branch head.\n"
+ "fast-forwarding your working tree from\n"
+ "commit %s."), sha1_to_hex(orig_head));
+
+ if (checkout_fast_forward(orig_head, curr_head, 0))
+ die(_("Cannot fast-forward your working tree.\n"
+ "After making sure that you saved anything precious from\n"
+ "$ git diff %s\n"
+ "output, run\n"
+ "$ git reset --hard\n"
+ "to recover."), sha1_to_hex(orig_head));
+ }
+
get_merge_heads(&merge_heads);
if (!merge_heads.nr)
die_no_merge_candidates(repo, refspecs);
- return run_merge();
+ 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();
}