Fix incorrect casting optimization for native JsTypes.

Change-Id: I19ccf553cc854f5d826e871a7fffed95bb78ab8e
gwtproject · Oct 6, 2015 · 6834a6f · 6834a6f
1 parent 94e4597
commit 6834a6f
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Showing 2 changed files with 15 additions and 8 deletions.
diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/JTypeOracle.java b/dev/core/src/com/google/gwt/dev/jjs/ast/JTypeOracle.java
@@ -413,16 +413,20 @@ public boolean canBeJavaScriptObject(JType type) {
   }
 
   /**
-   * True if the type is a JSO or interface implemented by JSO or a JsType without prototype.
+   * True if the type can be casted across different Java types that are unrelated.
    */
   public boolean canCrossCastLikeJso(JType type) {
-    return canBeJavaScriptObject(type) || isNonNativeJsTypeInterface(type);
+    return canBeJavaScriptObject(type) || isNativeJsType(type) || isNonNativeJsTypeInterface(type);
   }
 
   public boolean isNonNativeJsTypeInterface(JType type) {
     return type.isJsType() && type instanceof JInterfaceType && !type.isJsNative();
   }
 
+  private boolean isNativeJsType(JType type) {
+    return type.isJsNative() && type instanceof JClassType;
+  }
+
   public boolean castFailsTrivially(JReferenceType fromType, JReferenceType toType) {
     if (!fromType.canBeNull() && toType.isNullType()) {
       // Cannot cast non-nullable to null

diff --git a/user/test/com/google/gwt/core/client/interop/JsTypeTest.java b/user/test/com/google/gwt/core/client/interop/JsTypeTest.java
@@ -214,26 +214,29 @@ private static native MyJsInterfaceWithProtectedNames createMyJsInterfaceWithPro
   }-*/;
 
   public void testCasts() {
-    MyJsInterfaceWithPrototype myClass;
+    Object myClass;
+    assertNotNull(myClass = (ElementLikeJsInterface) createMyJsInterface());
     assertNotNull(myClass = (MyJsInterfaceWithPrototype) createMyJsInterface());
+    assertNotNull(myClass = (HTMLElement) createNativeButton());
 
     try {
-      assertNotNull(myClass = (MyJsInterfaceWithPrototype) createNativeButton());
+      assertNotNull(myClass = (HTMLElement) createMyJsInterface());
       fail();
     } catch (ClassCastException cce) {
       // Expected.
     }
 
-    ElementLikeJsInterface button;
-    // JsTypes without prototypes can cross-cast like JSOs
-    assertNotNull(button = (ElementLikeJsInterface) createMyJsInterface());
+    // Test cross cast for native types
+    Object nativeButton1 = (HTMLElement) createNativeButton();
+    Object nativeButton2 = (HTMLAnotherElement) nativeButton1;
 
     /*
      * If the optimizations are turned on, it is possible for the compiler to dead-strip the
      * variables since they are not used. Therefore the casts could potentially be stripped.
      */
     assertNotNull(myClass);
-    assertNotNull(button);
+    assertNotNull(nativeButton1);
+    assertNotNull(nativeButton2);
   }
 
   public void testInstanceOf_jsoWithProto() {