functional interfaces: ignore methods with type parameters during abstract method choosing

java/java-psi-api/src/com/intellij/psi/LambdaUtil.java

@@ -181,7 +181,8 @@ public class LambdaUtil {
       boolean subsignature = true;
       for (MethodSignature methodSignature : signatures) {
         if (!signature.equals(methodSignature)) {
-          if (!MethodSignatureUtil.isSubsignature(signature, methodSignature)) {
+          if (!MethodSignatureUtil.isSubsignature(signature, methodSignature) && 
+              methodSignature.getTypeParameters().length == 0) {
             subsignature = false;
             break;
           }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/GenericNotGenericInterfaceMethod.java

@@ -0,0 +1,16 @@
+class Test {
+
+  interface A {
+    <X> void m();
+  }
+
+  interface B {
+    void m();
+  }
+
+  interface C extends A, B { }
+
+  {
+    C c = ()-> {};
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/LambdaHighlightingTest.java

@@ -103,6 +103,7 @@ public class LambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testIDEA123308() {doTest();}
   public void testIntersection() {doTest();}
   public void testNoBoxingInLambdaFormalParams() {doTest();}
+  public void testGenericNotGenericInterfaceMethod() {doTest();}
 
   private void doTest() {
     doTest(false);