IDEA-64581 Groovy: Change Signature Refactoring shouldn't use parameter's initializer as default value

plugins/groovy/src/org/jetbrains/plugins/groovy/refactoring/changeSignature/GrChangeSignatureUsageProcessor.java

@@ -511,6 +511,10 @@ public class GrChangeSignatureUsageProcessor implements ChangeSignatureUsageProc
         else {
           if (skipOptionals && isParameterOptional(parameter)) continue;
           GrExpression fromText = null;
+          if (forceOptional(parameter)) {
+            skipOptionals = true;
+            continue;
+          }
           try {
             fromText = factory.createExpressionFromText(parameter.getDefaultValue());
           }
@@ -535,6 +539,10 @@ public class GrChangeSignatureUsageProcessor implements ChangeSignatureUsageProc
     }
   }
 
+  protected static boolean forceOptional(JavaParameterInfo parameter) {
+    return parameter instanceof GrParameterInfo && ((GrParameterInfo)parameter).forceOptional();
+  }
+
   private static void fixExceptions(PsiElement element, PsiClassType[] exceptions) {
     if (exceptions.length == 0) return;
     final GroovyPsiElement context =

plugins/groovy/src/org/jetbrains/plugins/groovy/refactoring/changeSignature/GrParameterInfo.java

@@ -15,7 +15,6 @@
  */
 package org.jetbrains.plugins.groovy.refactoring.changeSignature;
 
-import com.intellij.openapi.project.Project;
 import com.intellij.psi.*;
 import com.intellij.refactoring.changeSignature.JavaParameterInfo;
 import com.intellij.refactoring.util.CanonicalTypes;
@@ -37,7 +36,6 @@ public class GrParameterInfo implements JavaParameterInfo {
 
   public GrParameterInfo(GrParameter parameter, int position) {
     myPosition = position;
-    final Project project = parameter.getProject();
     myName = parameter.getName();
     final PsiType type = parameter.getDeclaredType();
     if (type != null) {
@@ -82,6 +80,7 @@ public class GrParameterInfo implements JavaParameterInfo {
   }
 
   public String getDefaultValue() {
+    if (forceOptional()) return getDefaultInitializer();
     return myDefaultValue;
   }
 
@@ -133,6 +132,10 @@ public class GrParameterInfo implements JavaParameterInfo {
     return getTypeText().length() == 0;
   }
 
+  public boolean forceOptional() {
+    return myPosition < 0 && myDefaultValue.length() == 0;
+  }
+
   /**
    * for testing only
    */

plugins/groovy/src/org/jetbrains/plugins/groovy/refactoring/changeSignature/GrTableParameterInfo.java

@@ -119,9 +119,6 @@ public class GrTableParameterInfo {
       type = null;
     }
     String defaultValue = getDefaultValue();
-    if (defaultValue.length() == 0) {
-      defaultValue = defaultInitializer;
-    }
     return new GrParameterInfo(getName(), defaultValue, defaultInitializer, type, myPosition);
   }
 }