Propagate vendor extensions to collection/map container metadata in annotation reader

src/main/java/org/datanucleus/api/jdo/metadata/JDOAnnotationReader.java

@@ -2112,6 +2112,12 @@ else if (contmd instanceof MapMetaData)
                     ordermd.setParent(mmd);
                     mmd.setOrderMetaData(ordermd);
                 }
+
+                // Propagate vendor extensions to container metadata (for cache, etc.)
+                if (extensions != null)
+                {
+                    contmd.addExtensions(extensions);
+                }
             }
             if (joinmd != null)
             {

src/test/java/org/datanucleus/api/jdo/metadata/JDOAnnotationReaderCollectionExtensionTest.java

@@ -0,0 +1,61 @@
+package org.datanucleus.api.jdo.metadata;
+
+import java.util.List;
+
+import javax.jdo.annotations.Extension;
+import javax.jdo.annotations.PersistenceCapable;
+import javax.jdo.annotations.Persistent;
+
+import junit.framework.TestCase;
+
+import org.datanucleus.ClassLoaderResolver;
+import org.datanucleus.PersistenceNucleusContextImpl;
+import org.datanucleus.metadata.AbstractClassMetaData;
+import org.datanucleus.metadata.AbstractMemberMetaData;
+import org.datanucleus.metadata.MetaDataManager;
+
+/**
+ * Tests that vendor extensions on collection/map fields are propagated to
+ * the container (CollectionMetaData / MapMetaData) by the annotation reader.
+ */
+public class JDOAnnotationReaderCollectionExtensionTest extends TestCase
+{
+    public JDOAnnotationReaderCollectionExtensionTest(String name)
+    {
+        super(name);
+    }
+
+    /**
+     * Model class with a collection field annotated with a vendor extension.
+     */
+    @PersistenceCapable
+    public static class ExtensionCollectionModel
+    {
+        @Persistent
+        @Extension(vendorName = "datanucleus", key = "cache", value = "false")
+        List<String> tags;
+    }
+
+    /**
+     * Verify that @Extension(key="cache", value="false") on a collection field
+     * reaches the CollectionMetaData.
+     */
+    public void testExtensionPropagatedToCollectionMetaData()
+    {
+        PersistenceNucleusContextImpl ctx = new PersistenceNucleusContextImpl("JDO", null);
+        MetaDataManager mgr = new JDOMetaDataManager(ctx);
+        ClassLoaderResolver clr = ctx.getClassLoaderResolver(getClass().getClassLoader());
+
+        mgr.loadClasses(new String[] { ExtensionCollectionModel.class.getName() }, getClass().getClassLoader());
+
+        AbstractClassMetaData cmd = mgr.getMetaDataForClass(ExtensionCollectionModel.class, clr);
+        AbstractMemberMetaData mmd = cmd.getMetaDataForMember("tags");
+
+        assertNotNull("Member metadata for 'tags' should not be null", mmd);
+        assertNotNull("Collection metadata should not be null", mmd.getCollection());
+        assertTrue("Collection metadata should have 'cache' extension",
+                mmd.getCollection().hasExtension("cache"));
+        assertEquals("Collection 'cache' extension should be 'false'",
+                "false", mmd.getCollection().getValueForExtension("cache"));
+    }
+}