lambda expression isCongruent: ensure target function type has no type parameters

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiLambdaExpressionImpl.java

@@ -177,9 +177,6 @@ public class PsiLambdaExpressionImpl extends ExpressionPsiElement implements Psi
     }
     final PsiExpressionList argsList = PsiTreeUtil.getParentOfType(this, PsiExpressionList.class);
 
-    leftType = FunctionalInterfaceParameterizationUtil.getGroundTargetType(leftType, this);
-
-    final PsiClassType.ClassResolveResult resolveResult = PsiUtil.resolveGenericsClassInType(leftType);
     if (MethodCandidateInfo.ourOverloadGuard.currentStack().contains(argsList)) {
       final MethodCandidateInfo.CurrentCandidateProperties candidateProperties = MethodCandidateInfo.getCurrentMethod(argsList);
       if (candidateProperties != null) {
@@ -194,6 +191,7 @@ public class PsiLambdaExpressionImpl extends ExpressionPsiElement implements Psi
       }
     }
 
+    leftType = FunctionalInterfaceParameterizationUtil.getGroundTargetType(leftType, this);
     if (!isPotentiallyCompatible(leftType)) {
       return false;
     }
@@ -202,9 +200,12 @@ public class PsiLambdaExpressionImpl extends ExpressionPsiElement implements Psi
       return true;
     }
 
+    final PsiClassType.ClassResolveResult resolveResult = PsiUtil.resolveGenericsClassInType(leftType);
     final PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(resolveResult);
     if (interfaceMethod == null) return false;
 
+    if (interfaceMethod.hasTypeParameters()) return false;
+
     final PsiSubstitutor substitutor = LambdaUtil.getSubstitutor(interfaceMethod, resolveResult);
 
     if (hasFormalParameterTypes()) {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/overloadResolution/LambdaIsNotCongruentWithFunctionalTypeWithTypeParams.java

@@ -0,0 +1,18 @@
+interface I {
+  void g();
+
+}
+interface J {
+  <<warning descr="Type parameter 'T' is never used">T</warning>> void f();
+}
+class Test {
+  void m(I i) {System.out.println(i);}
+  void m(J j) {System.out.println(j);}
+
+  void m2(J j){System.out.println(j);}
+
+  {
+    m (() -> {});
+    m2(<error descr="Target method is generic">() -> {}</error>);
+  }
+}

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

@@ -67,6 +67,10 @@ public class OverloadResolutionTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testLambdaIsNotCongruentWithFunctionalTypeWithTypeParams() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(true);
   }