1 files changed, 73 insertions, 0 deletions
diff --git a/dom/base/test/chrome/test_bug339494.xhtml b/dom/base/test/chrome/test_bug339494.xhtml
new file mode 100644
index 0000000000..203f6e644d
--- /dev/null
+++ b/dom/base/test/chrome/test_bug339494.xhtml
@@ -0,0 +1,73 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
+<?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css" type="text/css"?>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=339494
+-->
+<window title="Mozilla Bug 339494"
+  xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
+  xmlns:xul="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+
+<body  xmlns="http://www.w3.org/1999/xhtml">
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=339494">Mozilla Bug 339494</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+  <xul:hbox id="d"/>
+  <xul:hbox id="s"/>
+</div>
+<pre id="test">
+</pre>
+</body>
+
+<script class="testbody" type="application/javascript">
+
+/** Test for Bug 339494 **/
+SimpleTest.waitForExplicitFinish();
+
+(async function runTests() {
+  function promiseFlushingMutationObserver() {
+    return new Promise(SimpleTest.executeSoon);
+  }
+
+  await (async function() {
+    const d = document.getElementById("d");
+
+    d.setAttribute("hhh", "testvalue");
+    await promiseFlushingMutationObserver();
+
+    const observer = new MutationObserver((aMutationList, aObserver) => {
+      ok(!d.hasAttribute("hhh"), "Value check 1. There should be no value");
+      isnot(d.getAttribute("hhh"), "testvalue", "Value check 2");
+      aObserver.disconnect();
+      d.removeAttribute("hhh");
+      ok(true, "Reachability. We shouldn't have crashed");
+    });
+    observer.observe(d, { attributes: true });
+    d.removeAttribute("hhh");
+    await promiseFlushingMutationObserver();
+  })();
+
+  await (async function() {
+    const s = document.getElementById("s");
+
+    s.setAttribute("ggg", "testvalue");
+    await promiseFlushingMutationObserver();
+
+    const observer = new MutationObserver((aMutationList, aObserver) => {
+      ok(s.hasAttribute("ggg"), "Value check 3. There should be a value");
+      isnot(s.getAttribute("ggg"), "testvalue", "Value check 4");
+      is(s.getAttribute("ggg"), "othervalue", "Value check 5");
+    });
+    observer.observe(s, { attributes: true });
+    s.setAttribute("ggg", "othervalue");
+    await promiseFlushingMutationObserver();
+    observer.disconnect();
+  })();
+
+  SimpleTest.finish();
+})();
+</script>
+
+</window>