Java: Preserve comments when extracting method with duplicates (IDEA-194463)

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

@@ -57,8 +57,8 @@ public class ParametrizedDuplicates {
 
   private ParametrizedDuplicates(@NotNull PsiElement[] pattern,
                                  @NotNull ExtractMethodProcessor originalProcessor) {
-    pattern = getFilteredElements(pattern);
-    PsiElement firstElement = pattern.length != 0 ? pattern[0] : null;
+    PsiElement[] filteredPattern = getFilteredElements(pattern);
+    PsiElement firstElement = filteredPattern.length != 0 ? filteredPattern[0] : null;
     if (firstElement instanceof PsiStatement) {
       PsiElement[] copy = copyElements(pattern);
       myElements = wrapWithCodeBlock(copy, originalProcessor.getInputVariables());

java/java-tests/testData/refactoring/extractMethod/DuplicatePreserveComments.java

@@ -0,0 +1,13 @@
+class C {
+    void foo() {
+        <selection>/*a*/ // b
+        System.out.println(1);
+        /*c*/ // d</selection>
+    }
+
+    void bar() {
+        /*x*/
+        System.out.println(1);
+        /*z*/
+    }
+}

java/java-tests/testData/refactoring/extractMethod/DuplicatePreserveComments_after.java

@@ -0,0 +1,17 @@
+class C {
+    void foo() {
+        newMethod();
+    }
+
+    private void newMethod() {
+        /*a*/ // b
+        System.out.println(1);
+        /*c*/ // d
+    }
+
+    void bar() {
+        /*x*/
+        newMethod();
+        /*z*/
+    }
+}

java/java-tests/testSrc/com/intellij/java/refactoring/ExtractMethodTest.java

@@ -1287,6 +1287,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doDuplicatesTest();
   }
 
+  public void testDuplicatePreserveComments() throws Exception {
+    doDuplicatesTest();
+  }
+
   public void testBeforeCommentAfterSelectedFragment() throws Exception {
     doTest();
   }