getAllIds on Float32Array fails

[szegedi]

Trying to query all IDs on a Float32Array throws an IllegalArgumentException. The issue seems to be that there is a gap of undefined instance IDs between Float32Array and its superclass NativeTypedArrayView.

Here's a little test that illustrates the issue:

package org.mozilla.javascript.tests;

import junit.framework.TestCase;
import org.mozilla.javascript.*;

public class Float32ArrayTest extends TestCase {
    public void test() throws Exception {
        Context cx = Context.enter();
        cx.setLanguageVersion(Context.VERSION_ES6);
        Scriptable global = cx.initStandardObjects();
        ScriptableObject obj = (ScriptableObject)cx.evaluateString(global, "new Float32Array(5)", "", 1, null);
        obj.getAllIds();
        Context.exit();
    }
}

It results in:

java.lang.IllegalArgumentException: 9
	at org.mozilla.javascript.IdScriptableObject.getInstanceIdName(IdScriptableObject.java:699)
	at org.mozilla.javascript.typedarrays.NativeArrayBufferView.getInstanceIdName(NativeArrayBufferView.java:100)
	at org.mozilla.javascript.typedarrays.NativeTypedArrayView.getInstanceIdName(NativeTypedArrayView.java:400)
	at org.mozilla.javascript.IdScriptableObject.getIds(IdScriptableObject.java:629)
	at org.mozilla.javascript.ScriptableObject.getAllIds(ScriptableObject.java:995)
	at org.mozilla.javascript.tests.Float32ArrayTest.test(Float32ArrayTest.java:20)

The issue might be similar to #437.

[szegedi]

It seems to me that the below change fixes it. Not sure why these values were 10 and 11 in the first place, though. A less brittle way of specifying them, counting from superclass MAX_INSTANCE_ID might be desirable.

--- a/src/org/mozilla/javascript/typedarrays/NativeTypedArrayView.java
+++ b/src/org/mozilla/javascript/typedarrays/NativeTypedArrayView.java
@@ -439,8 +439,8 @@ public abstract class NativeTypedArrayView<T>
      * These must not conflict with ids in the parent since we delegate there for property dispatching.
      */
     private static final int
-        Id_length               = 10,
-        Id_BYTES_PER_ELEMENT    = 11,
+        Id_length               = 4,
+        Id_BYTES_PER_ELEMENT    = 5,
         MAX_INSTANCE_ID         = Id_BYTES_PER_ELEMENT;
 
 // #/string_id_map#