diff -r 44a2da4a2ab2 -r 925c144e1f1f widget/xpwidgets/nsTransferable.cpp
--- a/widget/xpwidgets/nsTransferable.cpp	Fri Jan 16 04:50:19 2015 +0100
+++ b/widget/xpwidgets/nsTransferable.cpp	Fri Jan 16 18:13:44 2015 +0100
@@ -60,7 +60,7 @@
 {
   // Now, check to see if we consider the data to be "too large"
   // as well as ensuring that private browsing mode is disabled
-  if (aDataLen > kLargeDatasetSize && aIsPrivBrowsing == false) {
+  if (aDataLen > kLargeDatasetSize && !aIsPrivBrowsing) {
     // if so, cache it to disk instead of memory
     if ( NS_SUCCEEDED(WriteCache(aData, aDataLen)) )
       return;