provably distinct: ? extends A should be provably distinct from Object until A is not an Object (IDEA-105695)

java/java-psi-api/src/com/intellij/psi/util/TypesDistinctProver.java

@@ -58,6 +58,11 @@ public class TypesDistinctProver {
               proveArrayTypeDistinct(((PsiWildcardType)type1).getManager().getProject(), (PsiArrayType)extendsBound, type2)) return true;
           final PsiClass boundClass1 = PsiUtil.resolveClassInType(extendsBound);
           if (boundClass1 == null) return false;
+
+          if (CommonClassNames.JAVA_LANG_OBJECT.equals(psiClass2.getQualifiedName())) {
+            return !CommonClassNames.JAVA_LANG_OBJECT.equals(boundClass1.getQualifiedName());
+          }
+
           return proveExtendsBoundsDistinct(type1, type2, boundClass1, psiClass2);
         }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/genericsHighlighting/IDEA105695.java

@@ -0,0 +1,10 @@
+import java.util.Map;
+
+public class Test {
+    void bar(Prop p) {
+         Map<? extends String, ? extends String> map = <error descr="Inconvertible types; cannot cast 'Prop' to 'java.util.Map<? extends java.lang.String,? extends java.lang.String>'">(Map<? extends String, ?  extends String>)p</error>;
+    }
+}
+
+abstract class Hashtble<K,V> implements Map<K,V> {}
+abstract class Prop extends Hashtble<Object, Object>{}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/GenericsHighlightingTest.java

@@ -206,6 +206,7 @@ public class GenericsHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testIDEA86875() { doTest5(false); }
   public void testIDEA103760(){ doTest5(false); }
   public void testIDEA105846(){ doTest5(false); }
+  public void testIDEA105695(){ doTest5(false); }
 
   public void testWildcardsOnRawTypes() { doTest5(false); }
   public void testDisableWithinBoundsCheckForSuperWildcards() {