8335967: "text-decoration: none" does not work with "A" HTML tags

Reviewed-by: abhiscxk, dmarkov, honkar, prr

src/java.desktop/share/classes/javax/swing/text/html/CSS.java

@@ -844,6 +844,10 @@ public class CSS implements Serializable {
     }
 
     static Object mergeTextDecoration(String value) {
+        if (value.startsWith("none")) {
+            return null;
+        }
+
         boolean underline = value.contains("underline");
         boolean strikeThrough = value.contains("line-through");
         if (!underline && !strikeThrough) {