Bug 996069 - Part1: nsContentUtils::IsSystemOrExpandedPrincipal. r=bz

content/base/public/nsContentUtils.h

@@ -1326,6 +1326,14 @@ public:
    */
   static bool IsExpandedPrincipal(nsIPrincipal* aPrincipal);
 
+  /**
+   * Returns true if aPrincipal is the system or an nsExpandedPrincipal.
+   */
+  static bool IsSystemOrExpandedPrincipal(nsIPrincipal* aPrincipal)
+  {
+    return IsSystemPrincipal(aPrincipal) || IsExpandedPrincipal(aPrincipal);
+  }
+
   /**
    * Gets the system principal from the security manager.
    */

docshell/base/nsDocShell.cpp

@@ -1544,17 +1544,9 @@ nsDocShell::LoadURI(nsIURI * aURI,
     //       for in InternalLoad is data:, javascript:, and about:blank
     //       URIs.  For other URIs this would all be dead wrong!
 
-    nsCOMPtr<nsIScriptSecurityManager> secMan =
-        do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     if (owner && mItemType != typeChrome) {
         nsCOMPtr<nsIPrincipal> ownerPrincipal = do_QueryInterface(owner);
-        bool isSystem;
+        if (nsContentUtils::IsSystemOrExpandedPrincipal(ownerPrincipal)) {
-        rv = secMan->IsSystemPrincipal(ownerPrincipal, &isSystem);
-        NS_ENSURE_SUCCESS(rv, rv);
-        nsCOMPtr<nsIExpandedPrincipal> ep = do_QueryInterface(ownerPrincipal);
-        if (isSystem || ep) {
             if (ownerIsExplicit) {
                 return NS_ERROR_DOM_SECURITY_ERR;
             }
@@ -1564,6 +1556,9 @@ nsDocShell::LoadURI(nsIURI * aURI,
     }
     if (!owner && !inheritOwner && !ownerIsExplicit) {
         // See if there's system or chrome JS code running
+        nsCOMPtr<nsIScriptSecurityManager> secMan =
+            do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
         rv = secMan->SubjectPrincipalIsSystem(&inheritOwner);
         if (NS_FAILED(rv)) {
             // Set it back to false