Preserve ArrayBuffer immutability in Structured{Serialize,Deserialize}

Author: gibson042

source

@@ -9745,6 +9745,16 @@ interface <dfn interface>DOMStringList</dfn> {
       </ol>
      </li>
 
+     <li>
+      <p>Otherwise, if <span>IsImmutableBuffer</span>(<var>value</var>) is true, then:</p>
+
+      <ol>
+       <li><p>Set <var>serialized</var> to { [[Type]]: "ImmutableArrayBuffer", [[ArrayBufferData]]:
+       <var>value</var>.[[ArrayBufferData]], [[ArrayBufferByteLength]]:
+       <var>value</var>.[[ArrayBufferByteLength]] }.</p></li>
+      </ol>
+     </li>
+
      <li>
       <p>Otherwise:</p>
 
@@ -9792,7 +9802,8 @@ interface <dfn interface>DOMStringList</dfn> {
      <var>memory</var>).</p></li>
 
      <li><p><span>Assert</span>: <var>bufferSerialized</var>.[[Type]] is "ArrayBuffer",
-     "ResizableArrayBuffer", "SharedArrayBuffer", or "GrowableSharedArrayBuffer".</p></li>
+     "ImmutableArrayBuffer", "ResizableArrayBuffer", "SharedArrayBuffer", or
+     "GrowableSharedArrayBuffer".</p></li>
 
      <li><p>If <var>value</var> has a [[DataView]] internal slot, then set <var>serialized</var> to
      { [[Type]]: "ArrayBufferView", [[Constructor]]: "DataView", [[ArrayBufferSerialized]]:
@@ -10187,6 +10198,20 @@ o.myself = o;</code></pre>
     </ol>
    </li>
 
+   <li>
+    <p>Otherwise, if <var>serialized</var>.[[Type]] is "ImmutableArrayBuffer", then:</p>
+
+    <ol>
+     <li><p>Set <var>value</var> to a new ArrayBuffer object in <var>targetRealm</var> whose
+     [[ArrayBufferData]] internal slot value is <var>serialized</var>.[[ArrayBufferData]], whose
+     [[ArrayBufferByteLength]] internal slot value is
+     <var>serialized</var>.[[ArrayBufferByteLength]], and whose [[ArrayBufferIsImmutable]] internal
+     slot is present.</p></li>
+
+     <li><p><span>Assert</span>: <span>IsImmutableBuffer</span>(<var>value</var>) is true.</p></li>
+    </ol>
+   </li>
+
    <li>
     <p>Otherwise, if <var>serialized</var>.[[Type]] is "ArrayBuffer", then set <var>value</var> to a
     new ArrayBuffer object in <var>targetRealm</var> whose [[ArrayBufferData]] internal slot value