raw substitutor when erasure happened during inference

java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java

@@ -366,7 +366,10 @@ public class InferenceSession {
     final InferenceVariable inferenceVariable = shouldResolveAndInstantiate(returnType, targetType);
     if (inferenceVariable != null) {
       final PsiSubstitutor substitutor = resolveSubset(Collections.singletonList(inferenceVariable), mySiteSubstitutor);
-      myConstraints.add(new TypeCompatibilityConstraint(targetType, PsiUtil.captureToplevelWildcards(substitutor.substitute(inferenceVariable.getParameter()), myContext)));
+      final PsiType substitutedReturnType = substitutor.substitute(inferenceVariable.getParameter());
+      if (substitutedReturnType != null) {
+        myConstraints.add(new TypeCompatibilityConstraint(targetType, PsiUtil.captureToplevelWildcards(substitutedReturnType, myContext)));
+      }
     } 
     else {
       if (FunctionalInterfaceParameterizationUtil.isWildcardParameterized(returnType)) {
@@ -707,7 +710,7 @@ public class InferenceSession {
         substitutor = substitutor.put(typeParameter, runtimeException);
       } 
       else {
-        substitutor = substitutor.put(typeParameter, getUpperBound(var, substitutor));
+        substitutor = substitutor.put(typeParameter, myErased ? null : getUpperBound(var, substitutor));
       }
     }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/genericsHighlighting8/Erasure.java

@@ -0,0 +1,9 @@
+import java.util.Collection;
+
+abstract class NCollections {
+  public <T> void foo(Collection<? extends T> coll) {
+    bar((Collection)coll);
+  }
+
+  public abstract <T2 extends Object & Comparable<? super T2>> T2 bar(Collection<? extends T2> coll);
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/GenericsHighlighting8Test.java

@@ -752,7 +752,9 @@ public class GenericsHighlighting8Test extends LightDaemonAnalyzerTestCase {
   }
 
   public void testSuperWildcardWithBoundPromotion() { doTest();}
-  
+
+  public void testErasure() throws Exception { doTest(); }
+
   private void doTest() {
     doTest(false);
   }