Merge branch 'bf/fetch-set-head-config' into jch

"git fetch" honors "remote.<remote>.followRemoteHEAD" settings to
tweak the remote-tracking HEAD in "refs/remotes/<remote>/HEAD".

* bf/fetch-set-head-config:
  remote set-head: set followRemoteHEAD to "warn" if "always"
  fetch set_head: add warn-if-not-$branch option
  fetch set_head: move warn advice into advise_if_enabled

Author: gitster

Documentation/config/remote.txt

@@ -106,10 +106,12 @@ remote.<name>.followRemoteHEAD::
 	How linkgit:git-fetch[1] should handle updates to `remotes/<name>/HEAD`.
 	The default value is "create", which will create `remotes/<name>/HEAD`
 	if it exists on the remote, but not locally, but will not touch an
-	already existing local reference.  Setting to "warn" will print
+	already existing local reference. Setting to "warn" will print
 	a message if the remote has a different value, than the local one and
-	in case there is no local reference, it behaves like "create". Setting
-	to "always" will silently update it to the value on the remote.
+	in case there is no local reference, it behaves like "create".
+	A variant on "warn" is "warn-if-not-$branch", which behaves like
+	"warn", but if `HEAD` on the remote is `$branch` it will be silent.
+	Setting to "always" will silently update it to the value on the remote.
 	Finally, setting it to "never" will never change or create the local
 	reference.
 +

advice.c

@@ -53,6 +53,7 @@ static struct {
 	[ADVICE_COMMIT_BEFORE_MERGE]			= { "commitBeforeMerge" },
 	[ADVICE_DETACHED_HEAD]				= { "detachedHead" },
 	[ADVICE_DIVERGING]				= { "diverging" },
+	[ADVICE_FETCH_SET_HEAD_WARN]			= { "fetchRemoteHEADWarn" },
 	[ADVICE_FETCH_SHOW_FORCED_UPDATES]		= { "fetchShowForcedUpdates" },
 	[ADVICE_FORCE_DELETE_BRANCH]			= { "forceDeleteBranch" },
 	[ADVICE_GRAFT_FILE_DEPRECATED]			= { "graftFileDeprecated" },

advice.h

@@ -20,6 +20,7 @@ enum advice_type {
 	ADVICE_COMMIT_BEFORE_MERGE,
 	ADVICE_DETACHED_HEAD,
 	ADVICE_DIVERGING,
+	ADVICE_FETCH_SET_HEAD_WARN,
 	ADVICE_FETCH_SHOW_FORCED_UPDATES,
 	ADVICE_FORCE_DELETE_BRANCH,
 	ADVICE_GRAFT_FILE_DEPRECATED,

builtin/fetch.c

@@ -1579,6 +1579,19 @@ static const char *strip_refshead(const char *name){
 	return name;
 }
 
+static void set_head_advice_msg(const char *remote, const char *head_name)
+{
+	const char message_advice_set_head[] =
+	N_("Run 'git remote set-head %s %s' to follow the change, or set\n"
+	   "'remote.%s.followRemoteHEAD' configuration option to a different value\n"
+	   "if you do not want to see this message. Specifically running\n"
+	   "'git config set remote.%s.followRemoteHEAD %s' will disable the warning\n"
+	   "until the remote changes HEAD to something else.");
+
+	advise_if_enabled(ADVICE_FETCH_SET_HEAD_WARN, _(message_advice_set_head),
+			remote, head_name, remote, remote, head_name);
+}
+
 static void report_set_head(const char *remote, const char *head_name,
 			struct strbuf *buf_prev, int updateres) {
 	struct strbuf buf_prefix = STRBUF_INIT;
@@ -1590,20 +1603,19 @@ static void report_set_head(const char *remote, const char *head_name,
 	if (prev_head && strcmp(prev_head, head_name)) {
 		printf("'HEAD' at '%s' is '%s', but we have '%s' locally.\n",
 			remote, head_name, prev_head);
-		printf("Run 'git remote set-head %s %s' to follow the change.\n",
-			remote, head_name);
+		set_head_advice_msg(remote, head_name);
 	}
 	else if (updateres && buf_prev->len) {
 		printf("'HEAD' at '%s' is '%s', "
 			"but we have a detached HEAD pointing to '%s' locally.\n",
 			remote, head_name, buf_prev->buf);
-		printf("Run 'git remote set-head %s %s' to follow the change.\n",
-			remote, head_name);
+		set_head_advice_msg(remote, head_name);
 	}
 	strbuf_release(&buf_prefix);
 }
 
-static int set_head(const struct ref *remote_refs, int follow_remote_head)
+static int set_head(const struct ref *remote_refs, int follow_remote_head,
+		const char *no_warn_branch)
 {
 	int result = 0, create_only, is_bare, was_detached;
 	struct strbuf b_head = STRBUF_INIT, b_remote_head = STRBUF_INIT,
@@ -1660,7 +1672,9 @@ static int set_head(const struct ref *remote_refs, int follow_remote_head)
 		result = 1;
 		goto cleanup;
 	}
-	if (follow_remote_head == FOLLOW_REMOTE_WARN && verbosity >= 0)
+	if (verbosity >= 0 &&
+		follow_remote_head == FOLLOW_REMOTE_WARN &&
+		(!no_warn_branch || strcmp(no_warn_branch, head_name)))
 		report_set_head(remote, head_name, &b_local_head, was_detached);
 
 cleanup:
@@ -1889,7 +1903,8 @@ static int do_fetch(struct transport *transport,
 				  "you need to specify exactly one branch with the --set-upstream option"));
 		}
 	}
-	if (set_head(remote_refs, transport->remote->follow_remote_head))
+	if (set_head(remote_refs, transport->remote->follow_remote_head,
+		transport->remote->no_warn_branch))
 		;
 		/*
 		 * Way too many cases where this can go wrong

builtin/remote.c

@@ -1438,6 +1438,7 @@ 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,
@@ -1448,8 +1449,10 @@ 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]);
@@ -1488,6 +1491,13 @@ 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);

remote.c

@@ -515,14 +515,23 @@ static int handle_config(const char *key, const char *value,
 		return parse_transport_option(key, value,
 					      &remote->server_options);
 	} else if (!strcmp(subkey, "followremotehead")) {
+		const char *no_warn_branch;
 		if (!strcmp(value, "never"))
 			remote->follow_remote_head = FOLLOW_REMOTE_NEVER;
 		else if (!strcmp(value, "create"))
 			remote->follow_remote_head = FOLLOW_REMOTE_CREATE;
-		else if (!strcmp(value, "warn"))
+		else if (!strcmp(value, "warn")) {
 			remote->follow_remote_head = FOLLOW_REMOTE_WARN;
-		else if (!strcmp(value, "always"))
+			remote->no_warn_branch = NULL;
+		} else if (skip_prefix(value, "warn-if-not-", &no_warn_branch)) {
+			remote->follow_remote_head = FOLLOW_REMOTE_WARN;
+			remote->no_warn_branch = no_warn_branch;
+		} else if (!strcmp(value, "always")) {
 			remote->follow_remote_head = FOLLOW_REMOTE_ALWAYS;
+		} else {
+			warning(_("unrecognized followRemoteHEAD value '%s' ignored"),
+				value);
+		}
 	}
 	return 0;
 }

remote.h

@@ -116,6 +116,7 @@ struct remote {
 	struct string_list server_options;
 
 	enum follow_remote_head_settings follow_remote_head;
+	const char *no_warn_branch;
 };
 
 /**

t/t5505-remote.sh

@@ -504,6 +504,17 @@ 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

t/t5510-fetch.sh

@@ -123,7 +123,6 @@ test_expect_success "fetch test followRemoteHEAD warn no change" '
 		git fetch >output &&
 		echo "${SQ}HEAD${SQ} at ${SQ}origin${SQ} is ${SQ}main${SQ}," \
 			"but we have ${SQ}other${SQ} locally." >expect &&
-		echo "Run ${SQ}git remote set-head origin main${SQ} to follow the change." >>expect &&
 		test_cmp expect output &&
 		head=$(git rev-parse refs/remotes/origin/HEAD) &&
 		branch=$(git rev-parse refs/remotes/origin/other) &&
@@ -160,7 +159,6 @@ test_expect_success "fetch test followRemoteHEAD warn detached" '
 		echo "${SQ}HEAD${SQ} at ${SQ}origin${SQ} is ${SQ}main${SQ}," \
 			"but we have a detached HEAD pointing to" \
 			"${SQ}${HEAD}${SQ} locally." >expect &&
-		echo "Run ${SQ}git remote set-head origin main${SQ} to follow the change." >>expect &&
 		test_cmp expect output
 	)
 '
@@ -183,6 +181,44 @@ test_expect_success "fetch test followRemoteHEAD warn quiet" '
 	)
 '
 
+test_expect_success "fetch test followRemoteHEAD warn-if-not-branch branch is same" '
+	test_when_finished "git config unset remote.origin.followRemoteHEAD" &&
+	(
+		cd "$D" &&
+		cd two &&
+		git rev-parse --verify refs/remotes/origin/other &&
+		git remote set-head origin other &&
+		git rev-parse --verify refs/remotes/origin/HEAD &&
+		git rev-parse --verify refs/remotes/origin/main &&
+		git config set remote.origin.followRemoteHEAD "warn-if-not-main" &&
+		actual=$(git fetch) &&
+		test "z" = "z$actual" &&
+		head=$(git rev-parse refs/remotes/origin/HEAD) &&
+		branch=$(git rev-parse refs/remotes/origin/other) &&
+		test "z$head" = "z$branch"
+	)
+'
+
+test_expect_success "fetch test followRemoteHEAD warn-if-not-branch branch is different" '
+	test_when_finished "git config unset remote.origin.followRemoteHEAD" &&
+	(
+		cd "$D" &&
+		cd two &&
+		git rev-parse --verify refs/remotes/origin/other &&
+		git remote set-head origin other &&
+		git rev-parse --verify refs/remotes/origin/HEAD &&
+		git rev-parse --verify refs/remotes/origin/main &&
+		git config set remote.origin.followRemoteHEAD "warn-if-not-some/different-branch" &&
+		git fetch >actual &&
+		echo "${SQ}HEAD${SQ} at ${SQ}origin${SQ} is ${SQ}main${SQ}," \
+			"but we have ${SQ}other${SQ} locally." >expect &&
+		test_cmp expect actual &&
+		head=$(git rev-parse refs/remotes/origin/HEAD) &&
+		branch=$(git rev-parse refs/remotes/origin/other) &&
+		test "z$head" = "z$branch"
+	)
+'
+
 test_expect_success "fetch test followRemoteHEAD always" '
 	test_when_finished "git config unset remote.origin.followRemoteHEAD" &&
 	(