Buffers should be resizable, too.

guacamole-common-js/src/main/resources/guacamole.js

@@ -439,9 +439,6 @@ Guacamole.Client = function(tunnel) {
             var width = parseInt(parameters[1]);
             var height = parseInt(parameters[2]);
 
-            // Only valid for layers (buffers auto-resize)
-            if (layer_index >= 0) {
-
             // Resize layer
             var layer_container = getLayerContainer(layer_index);
             layer_container.resize(width, height);
@@ -458,8 +455,6 @@ Guacamole.Client = function(tunnel) {
 
             }
 
-            } // end if layer (not buffer)
-
         },
 
         "sync": function(parameters) {