Change Signature: Rename parameter in overriding functions

#KT-4045 Fixed

idea/src/org/jetbrains/jet/plugin/refactoring/changeSignature/JetParameterInfo.java

@@ -21,15 +21,12 @@ import com.intellij.psi.PsiElement;
 import com.intellij.refactoring.changeSignature.ParameterInfo;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
 import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetFunction;
 import org.jetbrains.jet.lang.psi.JetParameter;
-import org.jetbrains.jet.lang.resolve.BindingContext;
-import org.jetbrains.jet.lang.resolve.name.Name;
-import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lexer.JetTokens;
-import org.jetbrains.jet.plugin.caches.resolve.ResolvePackage;
 import org.jetbrains.jet.renderer.DescriptorRenderer;
 
 import java.util.List;
@@ -76,30 +73,20 @@ public class JetParameterInfo implements ParameterInfo {
     }
 
     public String getInheritedName(boolean isInherited, @Nullable PsiElement inheritedFunction, @NotNull JetMethodDescriptor baseFunction) {
-        if (!(inheritedFunction instanceof JetFunction))
-            return name;
+        if (!(isInherited && inheritedFunction instanceof JetFunction)) return name;
+
+        FunctionDescriptor baseFunctionDescriptor = baseFunction.getDescriptor();
+        assert baseFunctionDescriptor != null : "No descriptor for " + baseFunction.getMethod().getText();
 
         JetFunction inheritedJetFunction = (JetFunction) inheritedFunction;
         List<JetParameter> inheritedParameters = inheritedJetFunction.getValueParameters();
 
-        if (!isInherited || oldIndex < 0 || oldIndex >= baseFunction.getParametersCount() || oldIndex >= inheritedParameters.size())
-            return name;
+        if (oldIndex < 0 || oldIndex >= baseFunction.getParametersCount() || oldIndex >= inheritedParameters.size()) return name;
 
-        JetParameterInfo oldParam = baseFunction.getParameters().get(oldIndex);
-        JetParameter inheritedParam = inheritedParameters.get(oldIndex);
-        String inheritedParamName = inheritedParam.getName();
+        String inheritedParamName = inheritedParameters.get(oldIndex).getName();
+        String oldParamName = baseFunctionDescriptor.getValueParameters().get(oldIndex).getName().asString();
 
-        if (oldParam.getName().equals(inheritedParamName)) {
-            BindingContext bindingContext = ResolvePackage.analyze(inheritedJetFunction);
-            JetScope parametersScope = JetChangeSignatureUsageProcessor.getFunctionBodyScope(inheritedJetFunction, bindingContext);
-
-            if (parametersScope != null && parametersScope.getLocalVariable(Name.identifier(name)) == null)
-                return name;
-            else
-                return inheritedParamName;
-        }
-        else
-            return inheritedParamName;
+        return oldParamName.equals(inheritedParamName) ? name : inheritedParamName;
     }
 
     @Override

idea/testData/refactoring/changeSignature/ParameterChangeInOverridesAfter.kt

@@ -0,0 +1,9 @@
+trait Foo {
+    fun bar(n: Int)
+}
+
+class Baz: Foo {
+    override fun bar(n: Int) {
+
+    }
+}

idea/testData/refactoring/changeSignature/ParameterChangeInOverridesBefore.kt

@@ -0,0 +1,9 @@
+trait Foo {
+    fun <caret>bar(s: String)
+}
+
+class Baz: Foo {
+    override fun bar(s: String) {
+
+    }
+}

idea/tests/org/jetbrains/jet/plugin/refactoring/changeSignature/JetChangeSignatureTest.java

@@ -295,6 +295,14 @@ public class JetChangeSignatureTest extends KotlinCodeInsightTestCase {
         doTest(changeInfo);
     }
 
+    public void testParameterChangeInOverrides() throws Exception {
+        JetChangeInfo changeInfo = getChangeInfo();
+        JetParameterInfo parameterInfo = changeInfo.getNewParameters()[0];
+        parameterInfo.setName("n");
+        parameterInfo.setTypeText("Int");
+        doTest(changeInfo);
+    }
+
     @NotNull
     @Override
     protected String getTestDataPath() {