1 files changed, 7 insertions, 1 deletions
diff --git a/application/palemoon/base/content/browser.js b/application/palemoon/base/content/browser.js
index eb4916e37..3feeef9b6 100644
--- a/application/palemoon/base/content/browser.js
+++ b/application/palemoon/base/content/browser.js
@@ -4408,7 +4408,13 @@ nsBrowserAccess.prototype = {
 
   openURI: function (aURI, aOpener, aWhere, aContext) {
     var newWindow = null;
-    var isExternal = (aContext == Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL);
+    var isExternal = !!(aContext & Ci.nsIBrowserDOMWindow.OPEN_EXTERNAL);
+
+    if (aOpener && isExternal) {
+      Cu.reportError("nsBrowserAccess.openURI did not expect an opener to be " +
+                     "passed if the context is OPEN_EXTERNAL.");
+      throw Cr.NS_ERROR_FAILURE;
+    }
 
     if (isExternal && aURI && aURI.schemeIs("chrome")) {
       dump("use -chrome command-line option to load external chrome urls\n");