1 files changed, 80 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_dying_cache.js b/browser/components/sessionstore/test/browser_dying_cache.js
new file mode 100644
index 0000000000..3b8a5b1197
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_dying_cache.js
@@ -0,0 +1,80 @@
+"use strict";
+
+/**
+ * This test ensures that after closing a window we keep its state data around
+ * as long as something keeps a reference to it. It should only be possible to
+ * read data after closing - writing should fail.
+ */
+
+add_task(async function test() {
+  // Open a new window.
+  let win = await promiseNewWindowLoaded();
+
+  // Load some URL in the current tab.
+  let flags = Ci.nsIWebNavigation.LOAD_FLAGS_REPLACE_HISTORY;
+  BrowserTestUtils.loadURIString(win.gBrowser.selectedBrowser, "about:robots", {
+    flags,
+  });
+  await promiseBrowserLoaded(win.gBrowser.selectedBrowser);
+
+  // Open a second tab and close the first one.
+  let tab = BrowserTestUtils.addTab(win.gBrowser, "about:mozilla");
+  await promiseBrowserLoaded(tab.linkedBrowser);
+  await TabStateFlusher.flush(tab.linkedBrowser);
+  await promiseRemoveTabAndSessionState(win.gBrowser.tabs[0]);
+
+  // Make sure our window is still tracked by sessionstore
+  // and the window state is as expected.
+  ok("__SSi" in win, "window is being tracked by sessionstore");
+  ss.setCustomWindowValue(win, "foo", "bar");
+  checkWindowState(win);
+
+  // Close our window.
+  await BrowserTestUtils.closeWindow(win);
+
+  // SessionStore should no longer track our window
+  // but it should still report the same state.
+  ok(!("__SSi" in win), "sessionstore does no longer track our window");
+  checkWindowState(win);
+
+  // Make sure we're not allowed to modify state data.
+  Assert.throws(
+    () => ss.setWindowState(win, {}),
+    /Window is not tracked/,
+    "we're not allowed to modify state data anymore"
+  );
+  Assert.throws(
+    () => ss.setCustomWindowValue(win, "foo", "baz"),
+    /Window is not tracked/,
+    "we're not allowed to modify state data anymore"
+  );
+});
+
+function checkWindowState(window) {
+  let {
+    windows: [{ tabs }],
+  } = ss.getWindowState(window);
+  is(tabs.length, 1, "the window has a single tab");
+  is(tabs[0].entries[0].url, "about:mozilla", "the tab is about:mozilla");
+
+  is(ss.getClosedTabCountForWindow(window), 1, "the window has one closed tab");
+  let [
+    {
+      state: {
+        entries: [{ url }],
+      },
+    },
+  ] = ss.getClosedTabDataForWindow(window);
+  is(url, "about:robots", "the closed tab is about:robots");
+
+  is(ss.getCustomWindowValue(window, "foo"), "bar", "correct extData value");
+}
+
+function shouldThrow(f) {
+  try {
+    f();
+  } catch (e) {
+    return true;
+  }
+  return null;
+}