src/java.desktop/share/classes/java/awt/image/ComponentSampleModel.java

@@ -1186,11 +1186,11 @@
            lineOffset += scanlineStride;
         }
     }
 
     public boolean equals(Object o) {
-        if ((o == null) || !(o instanceof ComponentSampleModel)) {
+        if ((o == null) || (o.getClass() !=  getClass())) {
             return false;
         }
 
         ComponentSampleModel that = (ComponentSampleModel)o;
         return this.width == that.width &&