1 files changed, 78 insertions, 0 deletions
diff --git a/browser/components/sessionstore/test/browser_506482.js b/browser/components/sessionstore/test/browser_506482.js
new file mode 100644
index 0000000000..a8e628ff7d
--- /dev/null
+++ b/browser/components/sessionstore/test/browser_506482.js
@@ -0,0 +1,78 @@
+/* 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/. */
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+
+function test() {
+  /** Test for Bug 506482 **/
+
+  // test setup
+  waitForExplicitFinish();
+
+  // read the sessionstore.js mtime (picked from browser_248970_a.js)
+  let profilePath = Services.dirsvc.get("ProfD", Ci.nsIFile);
+  function getSessionstoreFile() {
+    let sessionStoreJS = profilePath.clone();
+    sessionStoreJS.append("sessionstore.jsonlz4");
+    return sessionStoreJS;
+  }
+  function getSessionstorejsModificationTime() {
+    let file = getSessionstoreFile();
+    if (file.exists()) {
+      return file.lastModifiedTime;
+    }
+    return -1;
+  }
+
+  // delete existing sessionstore.js, to make sure we're not reading
+  // the mtime of an old one initially.
+  let sessionStoreJS = getSessionstoreFile();
+  if (sessionStoreJS.exists()) {
+    sessionStoreJS.remove(false);
+  }
+
+  // test content URL
+  const TEST_URL =
+    "data:text/html;charset=utf-8," +
+    "<body style='width: 100000px; height: 100000px;'><p>top</p></body>";
+
+  // preferences that we use
+  const PREF_INTERVAL = "browser.sessionstore.interval";
+
+  // make sure sessionstore.js is saved ASAP on all events
+  Services.prefs.setIntPref(PREF_INTERVAL, 0);
+
+  // get the initial sessionstore.js mtime (-1 if it doesn't exist yet)
+  let mtime0 = getSessionstorejsModificationTime();
+
+  // create and select a first tab
+  let tab = BrowserTestUtils.addTab(gBrowser, TEST_URL);
+  promiseBrowserLoaded(tab.linkedBrowser).then(() => {
+    // step1: the above has triggered some saveStateDelayed(), sleep until
+    // it's done, and get the initial sessionstore.js mtime
+    setTimeout(function step1() {
+      let mtime1 = getSessionstorejsModificationTime();
+      isnot(mtime1, mtime0, "initial sessionstore.js update");
+
+      // step2: test sessionstore.js is not updated on tab selection
+      // or content scrolling
+      gBrowser.selectedTab = tab;
+      tab.linkedBrowser.contentWindow.scrollTo(1100, 1200);
+      setTimeout(function step2() {
+        let mtime2 = getSessionstorejsModificationTime();
+        is(
+          mtime2,
+          mtime1,
+          "tab selection and scrolling: sessionstore.js not updated"
+        );
+
+        // ok, done, cleanup and finish
+        if (Services.prefs.prefHasUserValue(PREF_INTERVAL)) {
+          Services.prefs.clearUserPref(PREF_INTERVAL);
+        }
+        gBrowser.removeTab(tab);
+        finish();
+      }, 3500); // end of sleep after tab selection and scrolling
+    }, 3500); // end of sleep after initial saveStateDelayed()
+  });
+}