fetch: add --no-update-remote-refs

To allow running "git fetch" in the background, we want to ensure
that users still see when the remote refs update in their user-
facing fetch commands. Use a new --no-update-remote-refs option
to prevent storing these updates to refs/remotes.

Signed-off-by: Derrick Stolee <[email protected]>

Author: derrickstolee

Documentation/fetch-options.txt

@@ -250,6 +250,11 @@ endif::git-pull[]
 	'git-pull' the --ff-only option will still check for forced updates
 	before attempting a fast-forward update. See linkgit:git-config[1].
 
+--no-update-remote-refs::
+	By default, git updates the `refs/remotes/` refspace with the refs
+	advertised by the remotes during a `git fetch` command. With this
+	option, those refs will be ignored.
+
 -4::
 --ipv4::
 	Use IPv4 addresses only, ignoring IPv6 addresses.

builtin/fetch.c

@@ -79,6 +79,7 @@ static struct refspec refmap = REFSPEC_INIT_FETCH;
 static struct list_objects_filter_options filter_options;
 static struct string_list server_options = STRING_LIST_INIT_DUP;
 static struct string_list negotiation_tip = STRING_LIST_INIT_NODUP;
+static int update_remote_refs = 1;
 
 static int git_fetch_config(const char *k, const char *v, void *cb)
 {
@@ -200,6 +201,8 @@ static struct option builtin_fetch_options[] = {
 		 N_("run 'gc --auto' after fetching")),
 	OPT_BOOL(0, "show-forced-updates", &fetch_show_forced_updates,
 		 N_("check for forced-updates on all updated branches")),
+	OPT_BOOL(0, "update-remote-refs", &update_remote_refs,
+		 N_("update the refs/remotes/ refspace")),
 	OPT_END()
 };
 
@@ -745,6 +748,9 @@ static int update_local_ref(struct ref *ref,
 	const char *pretty_ref = prettify_refname(ref->name);
 	int fast_forward = 0;
 
+	if (!update_remote_refs && starts_with(ref->name, "refs/remotes/"))
+		return 0;
+
 	type = oid_object_info(the_repository, &ref->new_oid, NULL);
 	if (type < 0)
 		die(_("object %s not found"), oid_to_hex(&ref->new_oid));