fix dirty check for empty hstore #96

src/integration-test/groovy/net/kaleidos/hibernate/hstore/PostgresqlHstoreMapDomainIntegrationSpec.groovy

@@ -93,4 +93,41 @@ class PostgresqlHstoreMapDomainIntegrationSpec extends Specification {
             [foo: "bar"]           | "foo"     | "bar"
             ["foo,bar": "baz,qux"] | "foo,bar" | "baz,qux"
     }
+
+    @Unroll
+    void 'save a domain class with a empty map and validate that is not dirty right after retrieval'() {
+        setup:
+        def testHstoreMap = new TestHstoreMap(testAttributes: [:])
+
+        when: 'I save an instance'
+        testHstoreMap.save()
+
+        and: 'The instance is saved'
+        assert !testHstoreMap.hasErrors()
+
+        and: 'I retrieve it and check for dirty properties'
+        def retrievedTestHstoreMap = testHstoreMap.get(testHstoreMap.id)
+
+        then: 'It shouldn\'t be dirty right after db retrieval'
+        !retrievedTestHstoreMap.isDirty()
+    }
+
+    @Unroll
+    void 'save a domain class, modify it and validate that it\'s dirty'() {
+        setup:
+        def testHstoreMap = new TestHstoreMap(testAttributes: [:])
+
+        when: 'I save an instance'
+        testHstoreMap.save()
+
+        and: 'The instance is saved'
+        assert !testHstoreMap.hasErrors()
+
+        and: 'I retrieve it and modify a property'
+        def retrievedTestHstoreMap = testHstoreMap.get(testHstoreMap.id)
+        retrievedTestHstoreMap.testAttributes << [foo: 'bar']
+
+        then: 'It shouldn be dirty'
+        retrievedTestHstoreMap.isDirty()
+    }
 }

src/main/groovy/net/kaleidos/hibernate/usertype/HstoreMapType.groovy

@@ -51,7 +51,7 @@ class HstoreMapType implements UserType {
     }
 
     Object deepCopy(Object value) throws HibernateException {
-        value ? new HashMap(value as Map) : null
+        value == null ? null : new HashMap(value as Map)
     }
 
     boolean isMutable() {