diff --git a/content/base/public/nsIDocument.h b/content/base/public/nsIDocument.h
index f69869576a3a..fab5aa034a26 100644
--- a/content/base/public/nsIDocument.h
+++ b/content/base/public/nsIDocument.h
@@ -784,7 +784,7 @@ public:
   /**
    * Enumerate all subdocuments.
    * The enumerator callback should return PR_TRUE to continue enumerating, or
-   * PR_FALSE to stop.  This will never get passed a null aDocument.
+   * PR_FALSE to stop.
    */
   typedef PRBool (*nsSubDocEnumFunc)(nsIDocument *aDocument, void *aData);
   virtual void EnumerateSubDocuments(nsSubDocEnumFunc aCallback,
@@ -1090,7 +1090,7 @@ public:
   /**
    * Enumerate the external resource documents associated with this document.
    * The enumerator callback should return PR_TRUE to continue enumerating, or
-   * PR_FALSE to stop.  This callback will never get passed a null aDocument.
+   * PR_FALSE to stop.
    */
   virtual void EnumerateExternalResources(nsSubDocEnumFunc aCallback,
                                           void* aData) = 0;
diff --git a/content/base/src/nsDocument.cpp b/content/base/src/nsDocument.cpp
index 8fe7f84f0033..670faa2631a3 100644
--- a/content/base/src/nsDocument.cpp
+++ b/content/base/src/nsDocument.cpp
@@ -813,8 +813,7 @@ ExternalResourceEnumerator(nsIURI* aKey,
 {
   nsExternalResourceEnumArgs* args =
     static_cast<nsExternalResourceEnumArgs*>(aClosure);
-  PRBool next =
-    aData->mDocument ? args->callback(aData->mDocument, args->data) : PR_TRUE;
+  PRBool next = args->callback(aData->mDocument, args->data);
   return next ? PL_DHASH_NEXT : PL_DHASH_STOP;
 }
 
diff --git a/content/base/test/Makefile.in b/content/base/test/Makefile.in
index ba4be57d29a2..d06ea7ad7973 100644
--- a/content/base/test/Makefile.in
+++ b/content/base/test/Makefile.in
@@ -228,7 +228,6 @@ _TEST_FILES = 	test_bug5141.html \
 		file_XHRDocURI.xml^headers^ \
 		file_XHRDocURI.text \
 		file_XHRDocURI.text^headers^ \
-		test_bug459424.html \
 		$(NULL)
 
 libs:: $(_TEST_FILES)
diff --git a/content/base/test/test_bug459424.html b/content/base/test/test_bug459424.html
deleted file mode 100644
index 4d35d2a239d0..000000000000
--- a/content/base/test/test_bug459424.html
+++ /dev/null
@@ -1,38 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=459424
--->
-<head>
-  <title>Test for Bug 459424</title>
-  <script type="application/javascript" src="/MochiKit/MochiKit.js"></script>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=459424">Mozilla Bug 459424</a>
-<p id="display" style="mask: url(no-such-document-I-tell-you#x)"></p>
-<div id="content" style="display: none">
-  
-</div>
-<pre id="test">
-<script type="application/javascript">
-
-/** Test for Bug 459424 **/
-SimpleTest.waitForExplicitFinish();
-addLoadEvent(function() {
-  netscape.security.PrivilegeManager.enablePrivilege('UniversalXPConnect');
-  var viewer =
-    window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
-          .getInterface(Components.interfaces.nsIWebNavigation)
-          .QueryInterface(Components.interfaces.nsIDocShell)
-          .contentViewer
-          .QueryInterface(Components.interfaces.nsIMarkupDocumentViewer);
-  viewer.fullZoom = 2;
-  is(true, true, "Gotta test something");
-  SimpleTest.finish();
-});
-</script>
-</pre>
-</body>
-</html>
