TestCI bugfix investigation

.github/workflows/temp_maven_build_debug.yml

@@ -0,0 +1,26 @@
+# This workflow is copied from maven_build.yml and is temporarily used to throubleshoot failure that appears only in CI
+
+name: Java CI with Maven
+
+on:
+    push:
+        branches: [ main ]
+    pull_request:
+        branches: [ main ]
+
+jobs:
+    test:
+        runs-on: ubuntu-latest
+        name: Temp test of CI
+        steps:
+            - name: Check out repository
+              uses: actions/checkout@v2
+
+            - name: Set up JDK
+              uses: actions/setup-java@v1
+              with:
+                  java-version: 17
+                  architecture: x64
+            - name: Test with Maven
+              run: ./mvnw -Dtest=SharedSubscriptionTest test -pl broker --file pom.xml
+

broker/src/test/java/io/moquette/integration/mqtt5/SharedSubscriptionTest.java

@@ -193,6 +193,7 @@ private static void verifyPubPayload(MqttMessage received, String expectedPayloa
         MqttPublishMessage pub = (MqttPublishMessage) received;
         String payload = pub.payload().asByteBuf().toString(StandardCharsets.UTF_8);
         assertEquals(expectedPayload, payload);
+        assertTrue(pub.release(), "received message must be deallocated");
     }
 
     @NotNull