check that inferred intersection type doesn't contain same generic type with different type arguments (IDEA-170325)

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

@@ -1265,7 +1265,13 @@ public class InferenceSession {
       }
 
       if (type instanceof PsiIntersectionType) {
-        final String conflictingConjunctsMessage = ((PsiIntersectionType)type).getConflictingConjunctsMessage();
+        String conflictingConjunctsMessage = ((PsiIntersectionType)type).getConflictingConjunctsMessage();
+        if (conflictingConjunctsMessage == null) {
+          if (findParameterizationOfTheSameGenericClass(var.getBounds(InferenceBound.UPPER), pair -> pair.first == null || pair.second == null || pair.first.equals(pair.second)) != null) {
+            //warn if upper bounds has same generic class with different type arguments
+            conflictingConjunctsMessage = type.getPresentableText(false);
+          }
+        }
         if (conflictingConjunctsMessage != null) {
           registerIncompatibleErrorMessage("Type parameter " + var.getParameter().getName() + " has incompatible upper bounds: " + conflictingConjunctsMessage);
           return PsiType.NULL;

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/graphInference/ApplicabilityCheckFailsExpressionTypeCheckPasses.java

@@ -0,0 +1,15 @@
+
+import java.util.*;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+class A {
+
+  void m(final Stream<String> stream){
+    Set<String> ALLOWED_PROPS = unmodifiableSet <error descr="'unmodifiableSet(java.util.Set<? extends java.lang.String>)' in 'A' cannot be applied to '(java.util.HashSet<java.lang.String>)'">(stream.collect(Collectors.toCollection(HashSet::new)))</error>;
+  }
+
+  public static <T1> Set<T1> unmodifiableSet(Set<? extends T1> s) {
+    return null;
+  }
+}

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

@@ -174,6 +174,10 @@ public class GraphInferenceHighlightingTest extends LightDaemonAnalyzerTestCase
   //public void _testAssignabilityOfStandaloneExpressionsDuringApplicabilityCheck() { doTest(); }
   public void testRecursiveTypeWithCapture() { doTest(); }
 
+  public void testApplicabilityCheckFailsExpressionTypeCheckPasses() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }