Merge branch 'hn/url-push-tracking' into seen

When the push remote is specified as a URL, the fetch refspec of a
uniquely matching configured remote is now used to find and update
the remote-tracking branch (e.g., '@{push}').

* hn/url-push-tracking:
  remote: resolve URL-valued push tracking remotes
  remote: pass repository to push tracking helper

Author: gitster

Documentation/revisions.adoc

@@ -127,6 +127,9 @@ some output processing may assume ref names in UTF-8.
   `git push` were run while `branchname` was checked out (or the current
   `HEAD` if no branchname is specified). Like for '@\{upstream\}', we report
   the remote-tracking branch that corresponds to that branch at the remote.
+  If the push remote is specified as a URL, the fetch refspec of a uniquely
+  matching configured remote is used to find and update the remote-tracking
+  branch.
 +
 Here's an example to make it more clear:
 +

remote.c

@@ -1887,12 +1887,38 @@ const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
 	return branch->merge[0]->dst;
 }
 
-static char *tracking_for_push_dest(struct remote *remote,
+struct remote *repo_remote_for_push_tracking(struct repository *repo,
+					     struct remote *remote)
+{
+	struct remote *first_match = NULL;
+	struct remote_state *remote_state = repo->remote_state;
+
+	if (remote->origin != REMOTE_UNCONFIGURED || remote->url.nr != 1)
+		return remote;
+
+	for (int i = 0; i < remote_state->remotes_nr; i++) {
+		struct remote *candidate = remote_state->remotes[i];
+
+		if (!candidate || candidate == remote ||
+		    !remote_is_configured(candidate, 0) ||
+		    !remote_has_url(candidate, remote->url.v[0]))
+			continue;
+		if (first_match)
+			return remote;
+		first_match = candidate;
+	}
+
+	return first_match ? first_match : remote;
+}
+
+static char *tracking_for_push_dest(struct repository *repo,
+				    struct remote *remote,
 				    const char *refname,
 				    struct strbuf *err)
 {
 	char *ret;
 
+	remote = repo_remote_for_push_tracking(repo, remote);
 	ret = apply_refspecs(&remote->fetch, refname);
 	if (!ret)
 		return error_buf(err,
@@ -1925,21 +1951,21 @@ static char *branch_get_push_1(struct repository *repo,
 					 _("push refspecs for '%s' do not include '%s'"),
 					 remote->name, branch->name);
 
-		ret = tracking_for_push_dest(remote, dst, err);
+		ret = tracking_for_push_dest(repo, remote, dst, err);
 		free(dst);
 		return ret;
 	}
 
 	if (remote->mirror)
-		return tracking_for_push_dest(remote, branch->refname, err);
+		return tracking_for_push_dest(repo, remote, branch->refname, err);
 
 	switch (repo_config_values(repo)->push_default) {
 	case PUSH_DEFAULT_NOTHING:
 		return error_buf(err, _("push has no destination (push.default is 'nothing')"));
 
 	case PUSH_DEFAULT_MATCHING:
 	case PUSH_DEFAULT_CURRENT:
-		return tracking_for_push_dest(remote, branch->refname, err);
+		return tracking_for_push_dest(repo, remote, branch->refname, err);
 
 	case PUSH_DEFAULT_UPSTREAM:
 		return xstrdup_or_null(branch_get_upstream(branch, err));
@@ -1953,7 +1979,7 @@ static char *branch_get_push_1(struct repository *repo,
 			up = branch_get_upstream(branch, err);
 			if (!up)
 				return NULL;
-			cur = tracking_for_push_dest(remote, branch->refname, err);
+			cur = tracking_for_push_dest(repo, remote, branch->refname, err);
 			if (!cur)
 				return NULL;
 			if (strcmp(cur, up)) {

remote.h

@@ -345,6 +345,8 @@ char *remote_ref_for_branch(struct branch *branch, int for_push);
 
 const char *repo_default_remote(struct repository *repo);
 const char *repo_remote_from_url(struct repository *repo, const char *url);
+struct remote *repo_remote_for_push_tracking(struct repository *repo,
+					     struct remote *remote);
 
 /* returns true if the given branch has merge configuration given. */
 int branch_has_merge_config(struct branch *branch);

t/t5505-remote.sh

@@ -24,6 +24,28 @@ setup_repository () {
 	)
 }
 
+setup_url_pushremote () {
+	rm -rf fork.git client &&
+	git clone --bare one fork.git &&
+	git clone one client &&
+	fork_url="$TRASH_DIRECTORY/fork.git" &&
+	(
+		cd client &&
+		git checkout -b topic --track origin/main &&
+		git commit --allow-empty -m topic-change &&
+		git config push.default current &&
+		git config status.compareBranches "@{upstream} @{push}" &&
+		git config branch.topic.pushRemote "$fork_url" &&
+		git push
+	)
+}
+
+check_status () {
+	git -C client status >actual &&
+	cat >expected &&
+	test_cmp expected actual
+}
+
 tokens_match () {
 	echo "$1" | tr ' ' '\012' | sort | sed -e '/^$/d' >expect &&
 	echo "$2" | tr ' ' '\012' | sort | sed -e '/^$/d' >actual &&
@@ -1018,6 +1040,88 @@ test_expect_success 'rename a remote renames repo remote.pushDefault but keeps g
 	)
 '
 
+test_expect_success 'URL-valued pushRemote without matching remote is not trackable' '
+	setup_url_pushremote &&
+
+	check_status <<-EOF
+	On branch topic
+	Your branch is ahead of ${SQ}origin/main${SQ} by 1 commit.
+	  (use "git push" to publish your local commits)
+
+	nothing to commit, working tree clean
+	EOF
+'
+
+test_expect_success 'adding fork remote makes URL-valued pushRemote trackable' '
+	setup_url_pushremote &&
+
+	(
+		cd client &&
+		git remote rename origin upstream &&
+		git remote add -f origin "$fork_url"
+	) &&
+
+	check_status <<-EOF
+	On branch topic
+	Your branch is ahead of ${SQ}upstream/main${SQ} by 1 commit.
+
+	Your branch is up to date with ${SQ}origin/topic${SQ}.
+
+	nothing to commit, working tree clean
+	EOF
+'
+
+test_expect_success 'up-to-date URL push refreshes stale tracking branch' '
+	setup_url_pushremote &&
+	(
+		cd client &&
+		git remote rename origin upstream &&
+		git remote add -f origin "$fork_url" &&
+		git commit --allow-empty -m another-topic-change &&
+		git -C ../fork.git fetch ../client topic:topic
+	) &&
+
+	check_status <<-EOF &&
+	On branch topic
+	Your branch is ahead of ${SQ}upstream/main${SQ} by 2 commits.
+
+	Your branch is ahead of ${SQ}origin/topic${SQ} by 1 commit.
+	  (use "git push" to publish your local commits)
+
+	nothing to commit, working tree clean
+	EOF
+
+	git -C client push >actual 2>&1 &&
+	test_grep "Everything up-to-date" actual &&
+
+	check_status <<-EOF
+	On branch topic
+	Your branch is ahead of ${SQ}upstream/main${SQ} by 2 commits.
+
+	Your branch is up to date with ${SQ}origin/topic${SQ}.
+
+	nothing to commit, working tree clean
+	EOF
+'
+
+test_expect_success 'duplicate remote URL leaves URL-valued pushRemote ambiguous' '
+	setup_url_pushremote &&
+	(
+		cd client &&
+		git remote rename origin upstream &&
+		git remote add -f origin "$fork_url" &&
+		git remote add duplicate "$fork_url"
+	) &&
+
+	check_status <<-EOF
+	On branch topic
+	Your branch is ahead of ${SQ}upstream/main${SQ} by 1 commit.
+	  (use "git push" to publish your local commits)
+
+	nothing to commit, working tree clean
+	EOF
+'
+
 test_expect_success 'rename handles remote without fetch refspec' '
 	git clone --bare one no-refspec.git &&
 	# confirm assumption that bare clone does not create refspec

transport.c

@@ -1597,8 +1597,11 @@ int transport_push(struct repository *r,
 	if (!(flags & (TRANSPORT_PUSH_DRY_RUN |
 		       TRANSPORT_RECURSE_SUBMODULES_ONLY))) {
 		struct ref *ref;
+		struct remote *tracking_remote = repo_remote_for_push_tracking(
+			r, transport->remote);
+
 		for (ref = remote_refs; ref; ref = ref->next)
-			transport_update_tracking_ref(transport->remote, ref, verbose);
+			transport_update_tracking_ref(tracking_remote, ref, verbose);
 	}
 
 	if (porcelain && !push_ret)