Java: Fixed comparing potential matches when detecting duplicates of the extracted method (IDEA-182275)

java/java-analysis-impl/src/com/intellij/refactoring/util/duplicates/DuplicatesFinder.java

@@ -564,7 +564,7 @@ public class DuplicatesFinder {
       PsiElement child2 = children2[i];
       if (!matchPattern(child1, child2, candidates, match)) {
         matchedExtractablePart = matchExtractableExpression(child1, child2, candidates, match, true);
-        return matchedExtractablePart != null && matchedExtractablePart;
+        if (matchedExtractablePart == null || !matchedExtractablePart) return false;
       }
     }
 

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

@@ -0,0 +1,17 @@
+class WriteDifferentFieldsDuplicate {
+    Runnable x;
+    Runnable y;
+
+    private void foo() {
+        <selection>
+        if (x != null) {
+            x.run();
+            x = null;
+        }</selection>
+
+        if (y != null) {
+            y.run();
+            y = null;
+        }
+    }
+}

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

@@ -0,0 +1,21 @@
+class WriteDifferentFieldsDuplicate {
+    Runnable x;
+    Runnable y;
+
+    private void foo() {
+
+        newMethod();
+
+        if (y != null) {
+            y.run();
+            y = null;
+        }
+    }
+
+    private void newMethod() {
+        if (x != null) {
+            x.run();
+            x = null;
+        }
+    }
+}

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

@@ -1177,6 +1177,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testWriteDifferentFieldsDuplicate() throws Exception {
+    doDuplicatesTest();
+  }
+
   private void doTestDisabledParam() throws PrepareFailedException {
     final CodeStyleSettings settings = CodeStyleSettingsManager.getSettings(getProject());
     settings.ELSE_ON_NEW_LINE = true;