Expose nsIScriptSecurityManager::SecurityCompareURIs for use by nsGlobalWindow::SetNewDocument, to avoid spurious window.open same-origin violation errors (220421, r=caillon, sr=bzbarsky).

caps/idl/nsIScriptSecurityManager.idl

@@ -234,6 +234,14 @@ interface nsIScriptSecurityManager : nsIXPCSecurityManager
      */
     [noscript] nsIPrincipal getPrincipalFromContext(in JSContextPtr cx);
 
+    /**
+     * Utility method for comparing two URIs.  For security purposes, two URIs
+     * are equivalent if their schemes, hosts, and ports (if any) match.  This
+     * method returns true if aSubjectURI and aObjectURI have the same origin,
+     * false otherwise.
+     */
+    [noscript] boolean securityCompareURIs(in nsIURI aSubjectURI,
+                                           in nsIURI aObjectURI);
 };
 
 %{C++

caps/include/nsScriptSecurityManager.h

@@ -285,11 +285,6 @@ public:
 
     JSContext* GetSafeJSContext();
 
-    static nsresult
-    SecurityCompareURIs(nsIURI* aSourceURI,
-                        nsIURI* aTargetURI,
-                        PRBool* result);
-
 private:
 
     // GetScriptSecurityManager is the only call that can make one

caps/src/nsScriptSecurityManager.cpp

@@ -214,10 +214,7 @@ nsScriptSecurityManager::GetSafeJSContext()
     return cx;
 }
 
-/* Static function for comparing two URIs - for security purposes,
- * two URIs are equivalent if their scheme, host, and port are equal.
- */
-/*static*/ nsresult
+NS_IMETHODIMP
 nsScriptSecurityManager::SecurityCompareURIs(nsIURI* aSourceURI,
                                              nsIURI* aTargetURI,
                                              PRBool* result)

dom/src/base/nsGlobalWindow.cpp

@@ -528,10 +528,9 @@ GlobalWindowImpl::SetNewDocument(nsIDOMDocument* aDocument,
         isContentWindow = itemType != nsIDocShellTreeItem::typeChrome;
       }
 
-      PRBool isAboutBlank = PR_FALSE;
       nsCAutoString url;
       docURL->GetSpec(url);
-      isAboutBlank = url.Equals(NS_LITERAL_CSTRING("about:blank"));
+      PRBool isAboutBlank = url.Equals(NS_LITERAL_CSTRING("about:blank"));
 
       PRBool isSameOrigin = PR_FALSE;
       if (isAboutBlank && mOpenerScriptURL) {
@@ -540,9 +539,9 @@ GlobalWindowImpl::SetNewDocument(nsIDOMDocument* aDocument,
           nsCOMPtr<nsIURI> newDocURL;
           webNav->GetCurrentURI(getter_AddRefs(newDocURL));
           if (newDocURL && sSecMan) {
-            isSameOrigin =
-              NS_SUCCEEDED(sSecMan->CheckSameOriginURI(mOpenerScriptURL,
-                                                       newDocURL));
+            sSecMan->SecurityCompareURIs(mOpenerScriptURL,
+                                         newDocURL,
+                                         &isSameOrigin);
           }
         }
       }