diff -r 000000000000 -r 6474c204b198 xpcom/tests/TestStaticAtoms.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/tests/TestStaticAtoms.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,75 @@
+/* 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/. */
+
+#include "TestHarness.h"
+#include "TestingAtoms.cpp"
+#include "MoreTestingAtoms.cpp"
+
+int main(int argc, char** argv)
+{
+  ScopedXPCOM xpcom("TestStaticAtoms");
+  if (xpcom.failed()) {
+    return 1;
+  }
+
+  TestingAtoms::AddRefAtoms();
+
+  NS_SealStaticAtomTable();
+
+  nsCOMPtr<nsIAtom> atom = do_GetAtom("foo");
+  if (!atom) {
+    fail("Didn't get an atom for foo.");
+    return 1;
+  }
+  if (atom->IsStaticAtom()) {
+    passed("foo is a static atom");
+  } else {
+    fail("foo is not a static atom.");
+    return 1;
+  }
+  if (atom == TestingAtoms::foo) {
+    passed("foo is the right pointer");
+  } else {
+    fail("foo was not the right pointer");
+    return 1;
+  }
+  nsIAtom* staticAtom = NS_GetStaticAtom(NS_LITERAL_STRING("foo"));
+  if (!staticAtom) {
+    fail("Did not get a static atom for foo");
+    return 1;
+  }
+
+  if (atom == staticAtom) {
+    passed("do_GetAtom and NS_GetStaticAtom returned the same atom.");
+  } else {
+    fail("do_GetAtom and NS_GetStaticAtom returned different atoms.");
+    return 1;
+  }
+
+  MoreTestingAtoms::AddRefAtoms();
+  
+  atom = do_GetAtom("qux");
+  if (!atom) {
+    fail("Didn't get an atom for qux.");
+    return 1;
+  }
+  if (atom->IsStaticAtom()) {
+    passed("qux is a static atom");
+  } else {
+    fail("qux is not a static atom.");
+    return 1;
+  }
+  if (atom == MoreTestingAtoms::qux) {
+    passed("qux is the right pointer");
+  } else {
+    fail("qux was not the right pointer");
+    return 1;
+  }
+  staticAtom = NS_GetStaticAtom(NS_LITERAL_STRING("qux"));
+  if (staticAtom) {
+    fail("Got an atom for qux. The static atom table was not sealed properly.");
+    return 1;
+  }
+  return 0;
+}