diff --git a/xpfe/appshell/src/nsContentTreeOwner.cpp b/xpfe/appshell/src/nsContentTreeOwner.cpp
index c8be88e16ae0..2c9925f9f5e1 100644
--- a/xpfe/appshell/src/nsContentTreeOwner.cpp
+++ b/xpfe/appshell/src/nsContentTreeOwner.cpp
@@ -38,6 +38,7 @@
 #include "nsIEmbeddingSiteWindow2.h"
 #include "nsIPrompt.h"
 #include "nsIAuthPrompt.h"
+#include "nsIWindowCreator2.h"
 #include "nsIWindowMediator.h"
 #include "nsIXULBrowserWindow.h"
 #include "nsPIDOMWindow.h"
@@ -653,6 +654,11 @@ NS_IMETHODIMP nsContentTreeOwner::ApplyChromeFlags()
      the 'chromehidden' attribute of the <window> tag. */
   nsAutoString newvalue;
 
+  PRUint32 contextFlags;
+  mXULWindow->GetContextFlags(&contextFlags);
+  if (! (contextFlags & nsIWindowCreator2::PARENT_IS_LOADING_OR_RUNNING_TIMEOUT))
+    newvalue.Append(NS_LITERAL_STRING("popupcontrol "));
+
   if (! (mChromeFlags & nsIWebBrowserChrome::CHROME_MENUBAR))
     newvalue.Append(NS_LITERAL_STRING("menubar "));
 
diff --git a/xpfe/bootstrap/nsWindowCreator.cpp b/xpfe/bootstrap/nsWindowCreator.cpp
index 7c0d9b725d4e..1a412478a309 100644
--- a/xpfe/bootstrap/nsWindowCreator.cpp
+++ b/xpfe/bootstrap/nsWindowCreator.cpp
@@ -66,21 +66,30 @@
 
 #include "nsCOMPtr.h"
 #include "nsAppShellCIDs.h"
+#include "nsNetUtil.h"
+#include "nsString.h"
 #include "nsWidgetsCID.h"
 #include "nsWindowCreator.h"
 
 #include "nsIAppShell.h"
 #include "nsIAppShellService.h"
 #include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "nsIDOMLocation.h"
+#include "nsIDOMWindowInternal.h"
 #include "nsIInterfaceRequestor.h"
 #include "nsIInterfaceRequestorUtils.h"
 #include "nsIJSContextStack.h"
+#include "nsIPopupWindowManager.h"
+#include "nsIPref.h"
 #include "nsIServiceManager.h"
+#include "nsIURI.h"
 #include "nsIXULWindow.h"
 #include "nsIWebBrowserChrome.h"
 
 static NS_DEFINE_CID(kAppShellServiceCID, NS_APPSHELL_SERVICE_CID);
 static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
+static NS_DEFINE_CID(kPrefServiceCID, NS_PREF_CID);
 
 nsWindowCreator::nsWindowCreator() {
   NS_INIT_ISUPPORTS();
@@ -89,21 +98,44 @@ nsWindowCreator::nsWindowCreator() {
 nsWindowCreator::~nsWindowCreator() {
 }
 
-NS_IMPL_ISUPPORTS1(nsWindowCreator, nsIWindowCreator)
+NS_IMPL_ISUPPORTS2(nsWindowCreator, nsIWindowCreator, nsIWindowCreator2)
 
 NS_IMETHODIMP
 nsWindowCreator::CreateChromeWindow(nsIWebBrowserChrome *aParent,
                                     PRUint32 aChromeFlags,
                                     nsIWebBrowserChrome **_retval)
+{
+  return CreateChromeWindow2(aParent, aChromeFlags, 0, _retval);
+}
+
+NS_IMETHODIMP
+nsWindowCreator::CreateChromeWindow2(nsIWebBrowserChrome *aParent,
+                                     PRUint32 aChromeFlags,
+                                     PRUint32 aContextFlags,
+                                     nsIWebBrowserChrome **_retval)
 {
   NS_ENSURE_ARG_POINTER(_retval);
   *_retval = 0;
 
+  PRUint32         allow = nsIPopupWindowManager::eAllow;
+  nsCOMPtr<nsIURI> parentURI;
+
+  GetParentURI(aParent, getter_AddRefs(parentURI));
+  if (aContextFlags & PARENT_IS_LOADING_OR_RUNNING_TIMEOUT)
+    allow = AllowWindowCreation(parentURI);
+
   nsCOMPtr<nsIXULWindow> newWindow;
 
   if (aParent) {
+    if (allow == nsIPopupWindowManager::eDisallow)
+      return NS_OK; // ruse to not give scripts a catchable error
+    if (allow == nsIPopupWindowManager::eAllow &&
+        (aContextFlags & PARENT_IS_LOADING_OR_RUNNING_TIMEOUT))
+      aContextFlags &= ~PARENT_IS_LOADING_OR_RUNNING_TIMEOUT;
+
     nsCOMPtr<nsIXULWindow> xulParent(do_GetInterface(aParent));
     NS_ASSERTION(xulParent, "window created using non-XUL parent. that's unexpected, but may work.");
+
     if (xulParent)
       xulParent->CreateNewWindow(aChromeFlags, getter_AddRefs(newWindow));
     // And if it fails, don't try again without a parent. It could fail
@@ -125,10 +157,49 @@ nsWindowCreator::CreateChromeWindow(nsIWebBrowserChrome *aParent,
   }
 
   // if anybody gave us anything to work with, use it
-  nsCOMPtr<nsIInterfaceRequestor> thing(do_QueryInterface(newWindow));
-  if (thing)
-    thing->GetInterface(NS_GET_IID(nsIWebBrowserChrome), (void **) _retval);
+  if (newWindow) {
+    newWindow->SetContextFlags(aContextFlags);
+    nsCOMPtr<nsIInterfaceRequestor> thing(do_QueryInterface(newWindow));
+    if (thing)
+      thing->GetInterface(NS_GET_IID(nsIWebBrowserChrome), (void **) _retval);
+  }
 
   return *_retval ? NS_OK : NS_ERROR_FAILURE;
 }
 
+PRUint32
+nsWindowCreator::AllowWindowCreation(nsIURI *aURI)
+{
+  nsCOMPtr<nsIPopupWindowManager> pm(do_GetService(NS_POPUPWINDOWMANAGER_CONTRACTID));
+  if (!pm)
+    return nsIPopupWindowManager::eAllow;
+
+  PRUint32 permission;
+  if (NS_SUCCEEDED(pm->TestPermission(aURI, &permission)))
+    return permission;
+  return nsIPopupWindowManager::eAllow;
+}
+
+void
+nsWindowCreator::GetParentURI(nsIWebBrowserChrome *aParent, nsIURI **aURI)
+{
+  if (!aParent)
+    return;
+
+  nsCOMPtr<nsIDocShellTreeOwner> treeOwner(do_GetInterface(aParent));
+  if (treeOwner) {
+    nsCOMPtr<nsIDocShellTreeItem> content;
+    treeOwner->GetPrimaryContentShell(getter_AddRefs(content));
+    nsCOMPtr<nsIDOMWindowInternal> domParent(do_GetInterface(content));
+    if (domParent) {
+      nsCOMPtr<nsIDOMLocation> location;
+      domParent->GetLocation(getter_AddRefs(location));
+      if (location) {
+        nsAutoString url;
+        location->GetHref(url);
+        NS_NewURI(aURI, url);
+      }
+    }
+  }
+}
+
diff --git a/xpfe/bootstrap/nsWindowCreator.h b/xpfe/bootstrap/nsWindowCreator.h
index 524a6a3a0a1d..e9e03e5cd564 100644
--- a/xpfe/bootstrap/nsWindowCreator.h
+++ b/xpfe/bootstrap/nsWindowCreator.h
@@ -38,10 +38,12 @@
 #ifndef __nsWindowCreator_h_
 #define __nsWindowCreator_h_
 
-#include "nsIWindowCreator.h"
+#include "nsIWindowCreator2.h"
+
+class nsIURI;
 
 class nsWindowCreator :
-      public nsIWindowCreator
+      public nsIWindowCreator2
 {
 public:
   nsWindowCreator();
@@ -49,6 +51,11 @@ public:
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSIWINDOWCREATOR
+  NS_DECL_NSIWINDOWCREATOR2
+
+private:
+  PRUint32 AllowWindowCreation(nsIURI *aURI);
+  void     GetParentURI(nsIWebBrowserChrome *aParent, nsIURI **aURI);
 };
 
 #endif