1 files changed, 84 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_447951.js b/browser/components/sessionstore/test/browser_447951.js
new file mode 100644
index 0000000000..84eaca8b33
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_447951.js
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function test() {
+  /** Test for Bug 447951 **/
+
+  waitForExplicitFinish();
+  const baseURL =
+    "http://mochi.test:8888/browser/" +
+    "browser/components/sessionstore/test/browser_447951_sample.html#";
+
+  // Make sure the functionality added in bug 943339 doesn't affect the results
+  Services.prefs.setIntPref("browser.sessionstore.max_serialize_back", -1);
+  Services.prefs.setIntPref("browser.sessionstore.max_serialize_forward", -1);
+  registerCleanupFunction(function() {
+    Services.prefs.clearUserPref("browser.sessionstore.max_serialize_back");
+    Services.prefs.clearUserPref("browser.sessionstore.max_serialize_forward");
+  });
+
+  let tab = BrowserTestUtils.addTab(gBrowser);
+  promiseBrowserLoaded(tab.linkedBrowser).then(() => {
+    let tabState = { entries: [] };
+    let max_entries = Services.prefs.getIntPref(
+      "browser.sessionhistory.max_entries"
+    );
+    for (let i = 0; i < max_entries; i++) {
+      tabState.entries.push({ url: baseURL + i, triggeringPrincipal_base64 });
+    }
+
+    promiseTabState(tab, tabState)
+      .then(() => {
+        return TabStateFlusher.flush(tab.linkedBrowser);
+      })
+      .then(() => {
+        tabState = JSON.parse(ss.getTabState(tab));
+        is(
+          tabState.entries.length,
+          max_entries,
+          "session history filled to the limit"
+        );
+        is(tabState.entries[0].url, baseURL + 0, "... but not more");
+
+        // visit yet another anchor (appending it to session history)
+        SpecialPowers.spawn(tab.linkedBrowser, [], function() {
+          content.window.document.querySelector("a").click();
+        }).then(flushAndCheck);
+
+        function flushAndCheck() {
+          TabStateFlusher.flush(tab.linkedBrowser).then(check);
+        }
+
+        function check() {
+          tabState = JSON.parse(ss.getTabState(tab));
+          if (tab.linkedBrowser.currentURI.spec != baseURL + "end") {
+            // It may take a few passes through the event loop before we
+            // get the right URL.
+            executeSoon(flushAndCheck);
+            return;
+          }
+
+          is(
+            tab.linkedBrowser.currentURI.spec,
+            baseURL + "end",
+            "the new anchor was loaded"
+          );
+          is(
+            tabState.entries[tabState.entries.length - 1].url,
+            baseURL + "end",
+            "... and ignored"
+          );
+          is(
+            tabState.entries[0].url,
+            baseURL + 1,
+            "... and the first item was removed"
+          );
+
+          // clean up
+          gBrowser.removeTab(tab);
+          finish();
+        }
+      });
+  });
+}