fix for GRAILS-6378 "IllegalArgumentException: object is not an instance of declaring class"

Author: graemerocher

src/java/org/codehaus/groovy/grails/orm/hibernate/cfg/GrailsHibernateUtil.java

@@ -324,6 +324,21 @@ public static void incrementVersion(Object target) {
         }
     }
 
+    /**
+     * Ensures the meta class is correct for a given class
+     * 
+     * @param target The GroovyObject
+     * @param persistentClass The persistent class
+     */
+    public static void ensureCorrectGroovyMetaClass(Object target, Class persistentClass) {
+		if(target instanceof GroovyObject) {
+			GroovyObject go = ((GroovyObject)target);
+			if(!go.getMetaClass().getTheClass().equals(persistentClass)) {
+				go.setMetaClass(GroovySystem.getMetaClassRegistry().getMetaClass(persistentClass));
+			}
+		}
+	}
+    
     /**
      * Unwraps and initializes a HibernateProxy.
      * @param proxy The proxy

src/java/org/codehaus/groovy/grails/orm/hibernate/proxy/GroovyAwareJavassistLazyInitializer.java

@@ -14,6 +14,9 @@
  */
 package org.codehaus.groovy.grails.orm.hibernate.proxy;
 
+import groovy.lang.GroovyObject;
+import groovy.lang.GroovySystem;
+
 import java.io.Serializable;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -26,6 +29,7 @@
 import javassist.util.proxy.ProxyObject;
 
 import org.apache.commons.logging.LogFactory;
+import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsHibernateUtil;
 import org.codehaus.groovy.grails.plugins.orm.hibernate.HibernatePluginSupport;
 import org.hibernate.HibernateException;
 import org.hibernate.engine.SessionImplementor;
@@ -209,6 +213,7 @@ public Object invoke(
             }
             if (result == INVOKE_IMPLEMENTATION) {
                 Object target = getImplementation();
+                GrailsHibernateUtil.ensureCorrectGroovyMetaClass(target,persistentClass);
                 final Object returnValue;
                 try {
                     if (ReflectHelper.isPublic(persistentClass, thisMethod)) {
@@ -240,7 +245,8 @@ public Object invoke(
         return proceed.invoke(proxy, args);
     }
 
-    @Override
+
+	@Override
     protected Object serializableProxy() {
         return new SerializableProxy(
                 getEntityName(),

src/java/org/codehaus/groovy/grails/orm/hibernate/proxy/HibernateProxyHandler.java

@@ -19,6 +19,7 @@
 import java.lang.reflect.InvocationTargetException;
 
 import org.apache.commons.beanutils.PropertyUtils;
+import org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsHibernateUtil;
 import org.codehaus.groovy.grails.support.proxy.ProxyHandler;
 import org.hibernate.Hibernate;
 import org.hibernate.collection.AbstractPersistentCollection;
@@ -79,7 +80,10 @@ public Object unwrapProxy(final HibernateProxy proxy) {
 		if(lazyInitializer.isUninitialized()) {
 		    lazyInitializer.initialize();
 		}
-		return lazyInitializer.getImplementation();
+		final Object obj = lazyInitializer.getImplementation();
+		if(obj != null)
+			GrailsHibernateUtil.ensureCorrectGroovyMetaClass(obj,obj.getClass());
+		return obj;
 	}
 
 	public HibernateProxy getAssociationProxy(Object obj, String associationName) {