Fix quickFix for PROPERTY_TYPE_MISMATCH_ON_OVERRIDE

idea/src/org/jetbrains/jet/plugin/quickfix/ChangeVariableTypeFix.java

@@ -106,9 +106,6 @@ public class ChangeVariableTypeFix extends JetIntentionAction<JetVariableDeclara
                 if (property != null) {
                     BindingContext context = KotlinCacheManagerUtil.getDeclarationsBindingContext(property);
                     JetType lowerBoundOfOverriddenPropertiesTypes = QuickFixUtil.findLowerBoundOfOverriddenCallablesReturnTypes(context, property);
-                    if (lowerBoundOfOverriddenPropertiesTypes != null) {
-                        actions.add(new ChangeVariableTypeFix(property, lowerBoundOfOverriddenPropertiesTypes));
-                    }
 
                     PropertyDescriptor descriptor = (PropertyDescriptor) context.get(BindingContext.DECLARATION_TO_DESCRIPTOR, property);
                     assert descriptor != null : "Descriptor of property not available in binding context";
@@ -116,18 +113,31 @@ public class ChangeVariableTypeFix extends JetIntentionAction<JetVariableDeclara
                     assert propertyType != null : "Property type cannot be null if it mismatch something";
 
                     List<PropertyDescriptor> overriddenMismatchingProperties = new LinkedList<PropertyDescriptor>();
+                    boolean canChangeOverriddenPropertyType = true;
                     for (PropertyDescriptor overriddenProperty: descriptor.getOverriddenDescriptors()) {
                         JetType overriddenPropertyType = overriddenProperty.getReturnType();
-                        if (overriddenPropertyType != null && !JetTypeChecker.INSTANCE.isSubtypeOf(propertyType, overriddenPropertyType)) {
-                            overriddenMismatchingProperties.add(overriddenProperty);
+                        if (overriddenPropertyType != null) {
+                            if (!JetTypeChecker.INSTANCE.isSubtypeOf(propertyType, overriddenPropertyType)) {
+                                overriddenMismatchingProperties.add(overriddenProperty);
+                            }
+                            else if (overriddenProperty.isVar() && !JetTypeChecker.INSTANCE.equalTypes(overriddenPropertyType, propertyType)) {
+                                canChangeOverriddenPropertyType = false;
+                            }
+                            if (overriddenProperty.isVar() && lowerBoundOfOverriddenPropertiesTypes != null &&
+                                !JetTypeChecker.INSTANCE.equalTypes(lowerBoundOfOverriddenPropertiesTypes, overriddenPropertyType)) {
+                                lowerBoundOfOverriddenPropertiesTypes = null;
+                            }
                         }
                     }
 
-                    if (overriddenMismatchingProperties.size() == 1) {
-                        JetProperty overriddenProperty =
-                                (JetProperty) BindingContextUtils.descriptorToDeclaration(context, overriddenMismatchingProperties.get(0));
-                        if (overriddenProperty != null) {
-                            actions.add(new ChangeVariableTypeFix(overriddenProperty, propertyType));
+                    if (lowerBoundOfOverriddenPropertiesTypes != null) {
+                        actions.add(new ChangeVariableTypeFix(property, lowerBoundOfOverriddenPropertiesTypes));
+                    }
+
+                    if (overriddenMismatchingProperties.size() == 1 && canChangeOverriddenPropertyType) {
+                        PsiElement overriddenProperty = BindingContextUtils.descriptorToDeclaration(context, overriddenMismatchingProperties.get(0));
+                        if (overriddenProperty instanceof JetProperty) {
+                            actions.add(new ChangeVariableTypeFix((JetProperty) overriddenProperty, propertyType));
                         }
                     }
                 }

idea/testData/quickfix/override/typeMismatchOnOverride/afterChangeOverriddenPropertyType2.kt

@@ -0,0 +1,12 @@
+// "Change 'A.x' type to 'String'" "true"
+trait A {
+    var x: String
+}
+
+trait B {
+    var x: String
+}
+
+trait C : A, B {
+    override var x: String<caret>
+}

idea/testData/quickfix/override/typeMismatchOnOverride/beforeCantChangeOverriddenPropertyTypeToMatchOverridingProperty.kt

@@ -0,0 +1,13 @@
+// "Change 'A.x' type to 'String'" "false"
+// ERROR: <html>Var-property type is 'jet.String', which is not a type of overridden<br/><b>internal</b> <b>abstract</b> <b>var</b> x: jet.Int <i>defined in</i> A</html>
+trait A {
+    var x: Int
+}
+
+trait B {
+    var x: Any
+}
+
+trait C : A, B {
+    override var x: String<caret>
+}

idea/testData/quickfix/override/typeMismatchOnOverride/beforeCantChangePropertyTypeToMatchOverridenProperties.kt

@@ -0,0 +1,13 @@
+// "Change 'C.x' type to 'String'" "false"
+// ERROR: <html>Var-property type is 'jet.Int', which is not a type of overridden<br/><b>internal</b> <b>abstract</b> <b>var</b> x: jet.String <i>defined in</i> A</html>
+trait A {
+    var x: String
+}
+
+trait B {
+    var x: Any
+}
+
+trait C : A, B {
+    override var x: Int<caret>
+}

idea/testData/quickfix/override/typeMismatchOnOverride/beforeChangeOverriddenPropertyType2.kt

@@ -0,0 +1,12 @@
+// "Change 'A.x' type to 'String'" "true"
+trait A {
+    var x: Int
+}
+
+trait B {
+    var x: String
+}
+
+trait C : A, B {
+    override var x: String<caret>
+}

idea/tests/org/jetbrains/jet/plugin/quickfix/QuickFixTestGenerated.java

@@ -1023,9 +1023,24 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                 doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeCantChangeMultipleOverriddenPropertiesTypes.kt");
             }
             
-            @TestMetadata("beforeChangeOverriddenPropertyType.kt")
-            public void testChangeOverriddenPropertyType() throws Exception {
-                doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeChangeOverriddenPropertyType.kt");
+            @TestMetadata("beforeCantChangeOverriddenPropertyTypeToMatchOverridingProperty.kt")
+            public void testCantChangeOverriddenPropertyTypeToMatchOverridingProperty() throws Exception {
+                doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeCantChangeOverriddenPropertyTypeToMatchOverridingProperty.kt");
+            }
+            
+            @TestMetadata("beforeCantChangePropertyTypeToMatchOverridenProperties.kt")
+            public void testCantChangePropertyTypeToMatchOverridenProperties() throws Exception {
+                doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeCantChangePropertyTypeToMatchOverridenProperties.kt");
+            }
+            
+            @TestMetadata("beforeChangeOverriddenPropertyType1.kt")
+            public void testChangeOverriddenPropertyType1() throws Exception {
+                doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeChangeOverriddenPropertyType1.kt");
+            }
+            
+            @TestMetadata("beforeChangeOverriddenPropertyType2.kt")
+            public void testChangeOverriddenPropertyType2() throws Exception {
+                doTest("idea/testData/quickfix/override/typeMismatchOnOverride/beforeChangeOverriddenPropertyType2.kt");
             }
             
             @TestMetadata("beforeChangeOverridingPropertyTypeToFunctionType.kt")