Use default canvas size if one cannot be intelligently procured

diff --git a/src/Chart.Core.js b/src/Chart.Core.js
index 5dccd2ef9b1cb8d7864709f5fcb72f30d5b3d674..6fa0af7629824c3a8aaccbaafa1bcab69ed1e9c9 100755 (executable)
--- a/src/Chart.Core.js
+++ b/src/Chart.Core.js
@@ -37,8 +37,8 @@
                        }
                }
 
-               var width = this.width = computeDimension(context.canvas,'Width');
-               var height = this.height = computeDimension(context.canvas,'Height');
+               var width = this.width = computeDimension(context.canvas,'Width') || context.canvas.width;
+               var height = this.height = computeDimension(context.canvas,'Height') || context.canvas.height;
 
                // Firefox requires this to work correctly
                context.canvas.width  = width;