hook: allow event = "" to overwrite previous values

Add the ability for empty events to clear previously set multivalue
variables, so the newly added "hook.*.event" behave like the other
multivalued keys.

Suggested-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 10 deletions

diff --git a/hook.c b/hook.c
index 35c24bf33d..fee0a7ab4f 100644
--- a/hook.c
+++ b/hook.c
@@ -147,18 +147,27 @@ static int hook_config_lookup_all(const char *key, const char *value,
 	hook_name = xmemdupz(name, name_len);
 
 	if (!strcmp(subkey, "event")) {
-		struct string_list *hooks =
-			strmap_get(&data->event_hooks, value);
+		if (!*value) {
+			/* Empty values reset previous events for this hook. */
+			struct hashmap_iter iter;
+			struct strmap_entry *e;
 
-		if (!hooks) {
-			hooks = xcalloc(1, sizeof(*hooks));
-			string_list_init_dup(hooks);
-			strmap_put(&data->event_hooks, value, hooks);
-		}
+			strmap_for_each_entry(&data->event_hooks, &iter, e)
+				unsorted_string_list_remove(e->value, hook_name);
+		} else {
+			struct string_list *hooks =
+				strmap_get(&data->event_hooks, value);
+
+			if (!hooks) {
+				hooks = xcalloc(1, sizeof(*hooks));
+				string_list_init_dup(hooks);
+				strmap_put(&data->event_hooks, value, hooks);
+			}
 
-		/* Re-insert if necessary to preserve last-seen order. */
-		unsorted_string_list_remove(hooks, hook_name);
-		string_list_append(hooks, hook_name);
+			/* Re-insert if necessary to preserve last-seen order. */
+			unsorted_string_list_remove(hooks, hook_name);
+			string_list_append(hooks, hook_name);
+		}
 	} else if (!strcmp(subkey, "command")) {
 		/* Store command overwriting the old value */
 		char *old = strmap_put(&data->commands, hook_name,