Ticket #6308: 6308.patch

_source/plugins/resize/plugin.js

@@ -44 +44 @@
                                 if ( resizeVertical )
                                         height =  Math.max( config.resize_minHeight, Math.min( internalHeight, config.resize_maxHeight ) );
 
-                                editor.resize( width, height );
+                                // DO NOT impose fixed size with single direction resize. (#6308)
+                                editor.resize( resizeHorizontal? width : null, height );
                         }
 
                         function dragEndHandler ( evt )