Java: Fixed duplicate matching for complex expressions (IDEA-188127)

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

@@ -610,6 +610,9 @@ public class DuplicatesFinder {
     if (!myWithExtractedParameters || !(pattern instanceof PsiReferenceExpression) || !(candidate instanceof PsiReferenceExpression)) {
       return false;
     }
+    if (myPattern.length == 1 && myPattern[0] == pattern) {
+      return false;
+    }
     ExtractableExpressionPart part1 = ExtractableExpressionPart.matchVariable((PsiReferenceExpression)pattern, null);
     if (part1 == null || part1.myVariable == null) {
       return false;

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

@@ -0,0 +1,13 @@
+class CallChainExpression {
+    String foo() {
+        String s = <selection>A.a().b().c</selection>;
+        System.out.println(s);
+        return s;
+    }
+
+    static class A {
+        static A a() { return new A(); }
+        A b() { return this; }
+        String c = "";
+    }
+}

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

@@ -0,0 +1,17 @@
+class CallChainExpression {
+    String foo() {
+        String s = newMethod();
+        System.out.println(s);
+        return s;
+    }
+
+    private String newMethod() {
+        return A.a().b().c;
+    }
+
+    static class A {
+        static A a() { return new A(); }
+        A b() { return this; }
+        String c = "";
+    }
+}

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

@@ -1229,6 +1229,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     doExitPointsTest(false);
   }
 
+  public void testCallChainExpression() throws Exception {
+    doTest();
+  }
+
   private void doTestDisabledParam() throws PrepareFailedException {
     final CommonCodeStyleSettings settings = CodeStyleSettingsManager.getSettings(getProject()).getCommonSettings(JavaLanguage.INSTANCE);
     settings.ELSE_ON_NEW_LINE = true;