If t is of type T, comparison (t == null) may be true. No warning in this case

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowValueFactory.java

@@ -62,7 +62,7 @@ public class DataFlowValueFactory {
     }
 
     private Nullability getImmanentNullability(JetType type) {
-        return type.isNullable() ? Nullability.UNKNOWN : Nullability.NOT_NULL;
+        return type.isNullable() || TypeUtils.hasNullableSuperType(type) ? Nullability.UNKNOWN : Nullability.NOT_NULL;
     }
 
     @NotNull

compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/senslessComparisonWithNullOnTypeParameters.kt

@@ -0,0 +1,16 @@
+// The type checker used to think that T is not null no matter what the upper bound
+
+fun nullableUpperBound<T, INDIRECT: T>(t: T, ind: INDIRECT) {
+    if (t == null) {} // was a warning
+    if (t != null) {}  // was a warning
+    if (ind == null) {}  // was a warning
+    if (ind != null) {}  // was a warning
+}
+
+fun notNullUpperBound<T: Any, INDIRECT: T>(t: T, ind: INDIRECT) {
+    if (<!SENSELESS_COMPARISON!>t == null<!>) {} // still a warning
+    if (<!SENSELESS_COMPARISON!>t != null<!>) {} // still a warning
+    if (<!SENSELESS_COMPARISON!>ind == null<!>) {} // still a warning
+    if (<!SENSELESS_COMPARISON!>ind != null<!>) {} // still a warning
+}
+

compiler/testData/diagnostics/tests/nullableTypes/redundantNullableInSupertype.kt

@@ -3,6 +3,6 @@ trait X: Any<!NULLABLE_SUPERTYPE!>?<!><!REDUNDANT_NULLABLE!>?<!> {
 }
 
 fun interaction<T>(t: T) {
-    if (<!SENSELESS_COMPARISON!>t == null<!>) {}
+    if (t == null) {}
 
 }

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -2286,6 +2286,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/SenselessNullInWhen.kt");
             }
             
+            @TestMetadata("senslessComparisonWithNullOnTypeParameters.kt")
+            public void testSenslessComparisonWithNullOnTypeParameters() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/nullabilityAndAutoCasts/senslessComparisonWithNullOnTypeParameters.kt");
+            }
+            
         }
         
         @TestMetadata("compiler/testData/diagnostics/tests/nullableTypes")