[ISSUE #10835] fix(common): reject malformed topic config atomically

common/src/main/java/org/apache/rocketmq/common/TopicConfig.java

@@ -111,29 +111,38 @@ public String encode() {
 
     public boolean decode(final String in) {
         String[] strs = in.split(SEPARATOR);
-        if (strs.length >= 5) {
-            this.topicName = strs[0];
-
-            this.readQueueNums = Integer.parseInt(strs[1]);
-
-            this.writeQueueNums = Integer.parseInt(strs[2]);
-
-            this.perm = Integer.parseInt(strs[3]);
+        if (strs.length < 5) {
+            return false;
+        }
 
-            this.topicFilterType = TopicFilterType.valueOf(strs[4]);
+        int decodedReadQueueNums;
+        int decodedWriteQueueNums;
+        int decodedPerm;
+        TopicFilterType decodedFilterType;
+        try {
+            decodedReadQueueNums = Integer.parseInt(strs[1]);
+            decodedWriteQueueNums = Integer.parseInt(strs[2]);
+            decodedPerm = Integer.parseInt(strs[3]);
+            decodedFilterType = TopicFilterType.valueOf(strs[4]);
+        } catch (IllegalArgumentException e) {
+            return false;
+        }
 
-            if (strs.length >= 6) {
-                try {
-                    this.attributes = JSON.parseObject(strs[5], ATTRIBUTES_TYPE_REFERENCE.getType());
-                } catch (Exception e) {
-                    // ignore exception when parse failed, cause map's key/value can have ' ' char.
-                }
+        this.topicName = strs[0];
+        this.readQueueNums = decodedReadQueueNums;
+        this.writeQueueNums = decodedWriteQueueNums;
+        this.perm = decodedPerm;
+        this.topicFilterType = decodedFilterType;
+
+        if (strs.length >= 6) {
+            try {
+                this.attributes = JSON.parseObject(strs[5], ATTRIBUTES_TYPE_REFERENCE.getType());
+            } catch (Exception e) {
+                // ignore exception when parse failed, cause map's key/value can have ' ' char.
             }
-
-            return true;
         }
 
-        return false;
+        return true;
     }
 
     public String getTopicName() {

common/src/test/java/org/apache/rocketmq/common/TopicConfigTest.java

@@ -75,4 +75,16 @@ public void testDecodeWhenCompatible() {
 
         assertThat(decodeTopicConfig).isEqualTo(topicConfig);
     }
-}
+
+    @Test
+    public void testDecodeMalformedConfigDoesNotMutateState() {
+        TopicConfig topicConfig = new TopicConfig("original", 4, 4, perm);
+
+        boolean decoded = topicConfig.decode("changed invalid 8 6 SINGLE_TAG");
+
+        assertThat(decoded).isFalse();
+        assertThat(topicConfig.getTopicName()).isEqualTo("original");
+        assertThat(topicConfig.getReadQueueNums()).isEqualTo(4);
+        assertThat(topicConfig.getWriteQueueNums()).isEqualTo(4);
+    }
+}