[ISSUE #10253] Fix stale wildcardGroupMap entries caused by incorrect parsing during LiteTopic wildcard unregistration (#10254)

Author: Kris20030907

broker/src/main/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImpl.java

@@ -400,7 +400,7 @@ private void markWildcardGroup(String topic, String group) {
 
     private void unmarkWildcardGroupIfNecessary(String lmqName) {
         if (!LiteUtil.isLiteTopicQueue(lmqName)) { // must be topic@group
-            String[] topicAtGroup = StringUtils.split(lmqName);
+            String[] topicAtGroup = StringUtils.split(lmqName, "@");
             if (null == topicAtGroup || topicAtGroup.length != 2) {
                 return;
             }

broker/src/test/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImplTest.java

@@ -307,6 +307,34 @@ public void testAddCompleteSubscription_WildcardGroup() {
         assertEquals(1, registry.getActiveSubscriptionNum());
     }
 
+    /**
+     * Test removeCompleteSubscription cleans wildcard group metadata
+     */
+    @Test
+    public void testRemoveCompleteSubscription_WildcardGroupMetadataCleanup() {
+        String clientId = "testClient";
+        String group = "testGroup";
+        String topic = "testTopic";
+        Set<String> lmqNameAll = new HashSet<>();
+        lmqNameAll.add("lmq1");
+
+        SubscriptionGroupConfig groupConfig = new SubscriptionGroupConfig();
+        groupConfig.setGroupName(group);
+        groupConfig.setWildcardLiteGroup(true);
+        when(mockSubscriptionGroupManager.findSubscriptionGroupConfig(group)).thenReturn(groupConfig);
+
+        registry.addCompleteSubscription(clientId, group, topic, lmqNameAll, 1L);
+
+        assertTrue(registry.wildcardGroupMap.containsKey(topic));
+        assertTrue(registry.wildcardGroupMap.get(topic).contains(group));
+
+        registry.removeCompleteSubscription(clientId);
+
+        assertFalse(registry.wildcardGroupMap.containsKey(topic));
+        assertNull(registry.getLiteSubscription(clientId));
+        assertEquals(0, registry.getActiveSubscriptionNum());
+    }
+
     /**
      * Test addCompleteSubscription updates complete subscription
      */