1 files changed, 54 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_multiple_select_after_load.js b/browser/components/sessionstore/test/browser_multiple_select_after_load.js
new file mode 100644
index 0000000000..dcb896e435
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_multiple_select_after_load.js
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const URL = `data:text/html;charset=utf-8,
+<select id="select">
+  <option value="1"> 1
+  <option value="2"> 2
+  <option value="3"> 3
+</select>`;
+
+const VALUES = ["1", "3"];
+
+// Tests that a document that changes a <select> element's "multiple" attribute
+// *after* the load event (eg. perhaps in response to some user action) doesn't
+// crash the browser when being restored.
+add_task(async function () {
+  // Create new tab.
+  let tab = BrowserTestUtils.addTab(gBrowser, URL);
+  await promiseBrowserLoaded(tab.linkedBrowser);
+
+  // Change the "multiple" attribute of the <select> element and select some
+  // options.
+  await setPropertyOfFormField(tab.linkedBrowser, "select", "multiple", true);
+
+  for (let v of VALUES) {
+    await setPropertyOfFormField(
+      tab.linkedBrowser,
+      `option[value="${v}"]`,
+      "selected",
+      true
+    );
+  }
+
+  // Remove the tab.
+  await promiseRemoveTabAndSessionState(tab);
+
+  // Verify state of the closed tab.
+  let tabData = ss.getClosedTabDataForWindow(window);
+  Assert.deepEqual(
+    tabData[0].state.formdata.id.select,
+    VALUES,
+    "Collected correct formdata"
+  );
+
+  // Restore the close tab.
+  tab = ss.undoCloseTab(window, 0);
+  await promiseTabRestored(tab);
+  ok(true, "Didn't crash!");
+
+  // Cleanup.
+  gBrowser.removeTab(tab);
+});