remote set-head: set followRemoteHEAD to "warn" if "always"

When running "remote set-head" manually it is unlikely, that the user
would actually like to have "fetch" always update the remote/HEAD. On
the contrary, it is more likely, that the user would expect remote/HEAD
to stay the way they manually set it, and just forgot about having
"followRemoteHEAD" set to "always".

When "followRemoteHEAD" is set to "always" make running "remote
set-head" change the config to "warn".

Signed-off-by: Bence Ferdinandy <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

builtin/remote.c

@@ -1433,6 +1433,7 @@ static int set_head(int argc, const char **argv, const char *prefix)
 		b_local_head = STRBUF_INIT;
 	char *head_name = NULL;
 	struct ref_store *refs = get_main_ref_store(the_repository);
+	struct remote *remote;
 
 	struct option options[] = {
 		OPT_BOOL('a', "auto", &opt_a,
@@ -1443,8 +1444,10 @@ static int set_head(int argc, const char **argv, const char *prefix)
 	};
 	argc = parse_options(argc, argv, prefix, options,
 			     builtin_remote_sethead_usage, 0);
-	if (argc)
+	if (argc) {
 		strbuf_addf(&b_head, "refs/remotes/%s/HEAD", argv[0]);
+		remote = remote_get(argv[0]);
+	}
 
 	if (!opt_a && !opt_d && argc == 2) {
 		head_name = xstrdup(argv[1]);
@@ -1483,6 +1486,13 @@ static int set_head(int argc, const char **argv, const char *prefix)
 	}
 	if (opt_a)
 		report_set_head_auto(argv[0], head_name, &b_local_head, was_detached);
+	if (remote->follow_remote_head == FOLLOW_REMOTE_ALWAYS) {
+		struct strbuf config_name = STRBUF_INIT;
+		strbuf_addf(&config_name,
+			"remote.%s.followremotehead", remote->name);
+		git_config_set(config_name.buf, "warn");
+		strbuf_release(&config_name);
+	}
 
 cleanup:
 	free(head_name);

t/t5505-remote.sh

@@ -505,6 +505,17 @@ test_expect_success 'set-head --auto has no problem w/multiple HEADs' '
 	)
 '
 
+test_expect_success 'set-head changes followRemoteHEAD always to warn' '
+	(
+		cd test &&
+		git config set remote.origin.followRemoteHEAD "always" &&
+		git remote set-head --auto origin &&
+		git config get remote.origin.followRemoteHEAD >actual &&
+		echo "warn" >expect &&
+		test_cmp expect actual
+	)
+'
+
 cat >test/expect <<\EOF
 refs/remotes/origin/side2
 EOF