replace code duplicates: move change signature out of write action

java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java

@@ -1229,8 +1229,12 @@ public class ExtractMethodProcessor implements MatchProvider {
     return result;
   }
 
-  public PsiElement processMatch(Match match) throws IncorrectOperationException {
+  @Override
+  public void prepareSignature(Match match) {
     MatchUtil.changeSignature(match, myExtractedMethod);
+  }
+
+  public PsiElement processMatch(Match match) throws IncorrectOperationException {
     if (RefactoringUtil.isInStaticContext(match.getMatchStart(), myExtractedMethod.getContainingClass())) {
       PsiUtil.setModifierProperty(myExtractedMethod, PsiModifier.STATIC, true);
     }

java/java-impl/src/com/intellij/refactoring/util/duplicates/ConstantMatchProvider.java

@@ -40,6 +40,9 @@ class ConstantMatchProvider implements MatchProvider {
     myMatches = matches;
   }
 
+  @Override
+  public void prepareSignature(Match match) {}
+
   @Override
   public PsiElement processMatch(Match match) throws IncorrectOperationException {
     final PsiClass containingClass = myField.getContainingClass();

java/java-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesImpl.java

@@ -140,6 +140,9 @@ public class DuplicatesImpl {
       HighlightManager.getInstance(project).removeSegmentHighlighter(editor, highlighters.get(0));
     }
 
+    // call change signature when needed
+    provider.prepareSignature(match);
+
     new WriteCommandAction(project, MethodDuplicatesHandler.REFACTORING_NAME, MethodDuplicatesHandler.REFACTORING_NAME) {
       @Override
       protected void run(@NotNull Result result) throws Throwable {

java/java-impl/src/com/intellij/refactoring/util/duplicates/MatchProvider.java

@@ -17,7 +17,6 @@ package com.intellij.refactoring.util.duplicates;
 
 import com.intellij.psi.PsiElement;
 import com.intellij.util.IncorrectOperationException;
-import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -26,6 +25,12 @@ import java.util.List;
  * @author dsl
  */
 public interface MatchProvider {
+  /**
+   * Call change signature here to avoid refactoring under write action
+   * @param match match which requires signature to be changed e.g. due to stronger expected type, etc
+   */
+  void prepareSignature(Match match);
+
   PsiElement processMatch(Match match) throws IncorrectOperationException;
 
   List<Match> getDuplicates();

java/java-impl/src/com/intellij/refactoring/util/duplicates/MethodDuplicatesMatchProvider.java

@@ -47,8 +47,12 @@ class MethodDuplicatesMatchProvider implements MatchProvider {
   }
 
   @Override
-  public PsiElement processMatch(Match match) throws IncorrectOperationException {
+  public void prepareSignature(Match match) {
     MatchUtil.changeSignature(match, myMethod);
+  }
+
+  @Override
+  public PsiElement processMatch(Match match) throws IncorrectOperationException {
     final PsiClass containingClass = myMethod.getContainingClass();
     if (isEssentialStaticContextAbsent(match)) {
       PsiUtil.setModifierProperty(myMethod, PsiModifier.STATIC, true);