gvfs: allow overriding core.gvfs

We found a user who had set "core.gvfs = false" in their global
config. This should not have been necessary, but it also should not
have caused a problem. However, it did.

The reason is that gvfs_load_config_value() is called from config.c
when reading config key/value pairs from all the config files. The
local config should override the global config, and this is done by
config.c reading the global config first then reading the local
config. However, our logic only allowed writing the core_gvfs
variable once.

Put the guards against multiple assignments of core_gvfs into
gvfs_config_is_set() instead, because that will fix the problem
_and_ keep multiple calls to gvfs_config_is_set() from slowing down.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>

gvfs.c

@@ -14,9 +14,6 @@ static int early_core_gvfs_config(const char *var, const char *value, void *data
 
 void gvfs_load_config_value(const char *value)
 {
-	if (gvfs_config_loaded)
-		return;
-
 	if (value)
 		core_gvfs = git_config_bool_or_int("core.gvfs", value, &core_gvfs_is_bool);
 	else if (startup_info->have_repository == 0)
@@ -27,12 +24,13 @@ void gvfs_load_config_value(const char *value)
 	/* Turn on all bits if a bool was set in the settings */
 	if (core_gvfs_is_bool && core_gvfs)
 		core_gvfs = -1;
-
-	gvfs_config_loaded = 1;
 }
 
 int gvfs_config_is_set(int mask)
 {
-	gvfs_load_config_value(NULL);
+	if (!gvfs_config_loaded)
+		gvfs_load_config_value(NULL);
+
+	gvfs_config_loaded = 1;
 	return (core_gvfs & mask) == mask;
 }

t/t0021-conversion.sh

@@ -352,6 +352,10 @@ test_expect_success "filter: smudge filters blocked when under GVFS" '
 	test_config filter.empty-in-repo.smudge "echo smudged && cat" &&
 	test_config core.gvfs 64 &&
 
+	test_must_fail git checkout &&
+
+	# ensure the local core.gvfs setting overwrites the global setting
+	git config --global core.gvfs false &&
 	test_must_fail git checkout
 '