diff -r 000000000000 -r 6474c204b198 tbb-tests/browser_tor_bug2950.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tbb-tests/browser_tor_bug2950.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+// # Regression tests for tor Bug #2950, Make Permissions Manager memory-only
+// Ensures that permissions.sqlite file in profile directory is not written to,
+// even when we write a value to Firefox's permissions database.
+
+// The requisite test() function.
+function test() {
+
+// Needed because of asynchronous part later in the test.
+waitForExplicitFinish();
+
+// Shortcut
+let Ci = Components.interfaces;
+
+// ## utility functions
+
+// __uri(spec)__.
+// Creates an nsIURI instance from a spec
+// (string address such as "http://torproject.org").
+let uri = spec => Services.io.newURI(spec, null, null);
+
+// __setPermission(spec, key, value)__.
+// Sets the site permission of type key to value, for the site located at address spec.
+let setPermission = (spec, key, value) => SitePermissions.set(uri(spec), key, value);
+
+// __getPermission(spec, key)__.
+// Reads the site permission value for permission type key, for the site
+// located at address spec.
+let getPermission = (spec, key) => SitePermissions.get(uri(spec), key);
+
+// __profileDirPath__.
+// The Firefox Profile directory. Expected location of various persistent files.
+let profileDirPath = Services.dirsvc.get("ProfD", Components.interfaces.nsIFile).path;
+
+// __fileInProfile(fileName)__.
+// Returns an nsIFile instance corresponding to a file in the Profile directory.
+let fileInProfile = fileName => FileUtils.File(profileDirPath + "/" + fileName);
+
+// ## Now let's run the test.
+
+let SITE = "http://torproject.org",
+    KEY = "popup";
+
+let permissionsFile = fileInProfile("permissions.sqlite"),
+                      lastModifiedTime = null,
+                      newModifiedTime = null;
+if (permissionsFile.exists()) {
+  lastModifiedTime = permissionsFile.lastModifiedTime;
+}
+// Read the original value of the permission.
+let originalValue = getPermission(SITE, KEY);
+
+// We need to delay by at least 1000 ms, because that's the granularity
+// of file time stamps, it seems.
+window.setTimeout(
+  function () {
+    // Set the permission to a new value.
+    setPermission(SITE, KEY, (originalValue === 0) ? 1 : 0);
+    // Now read back the permission value again.
+    let newReadValue = getPermission(SITE, KEY);
+    // Compare to confirm that the permission
+    // value was successfully changed.
+    isnot(newReadValue, originalValue, "Set a value in permissions db (perhaps in memory).");;
+    // If file existed or now exists, get the current time stamp.
+    if (permissionsFile.exists()) {
+    	newModifiedTime = permissionsFile.lastModifiedTime;
+    }
+    // If file was created or modified since we began this test,
+    // then permissions db is not memory only. Complain!
+    is(lastModifiedTime, newModifiedTime, "Don't write to permissions.sqlite file on disk.");
+    // We are done with the test.
+    finish();
+  }, 1100);
+
+} // test()