1 files changed, 20 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_579879.js b/browser/components/sessionstore/test/browser_579879.js
new file mode 100644
index 000000000..6886be038
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_579879.js
@@ -0,0 +1,20 @@
+"use strict";
+
+add_task(function* () {
+  let tab1 = gBrowser.addTab("data:text/plain;charset=utf-8,foo");
+  gBrowser.pinTab(tab1);
+
+  yield promiseBrowserLoaded(tab1.linkedBrowser);
+  let tab2 = gBrowser.addTab();
+  gBrowser.pinTab(tab2);
+
+  is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 is at the first position");
+  yield promiseRemoveTab(tab1);
+
+  tab1 = undoCloseTab();
+  ok(tab1.pinned, "pinned tab 1 has been restored as a pinned tab");
+  is(Array.indexOf(gBrowser.tabs, tab1), 0, "pinned tab 1 has been restored to the first position");
+
+  yield BrowserTestUtils.removeTab(tab1);
+  yield BrowserTestUtils.removeTab(tab2);
+});