Prevent error in console if NaN in path to draw

Original idea from morrisjs#705

lib/morris.donut.coffee

@@ -252,15 +252,18 @@ class Morris.DonutSegment extends Morris.EventEmitter
       "A#{r},#{r},0,#{@is_long},0,#{ix1},#{iy1}")
 
   render: ->
-    @arc = @drawDonutArc(@hilight, @color)
-    @seg = @drawDonutSegment(
-      @path, 
-      @color, 
-      @backgroundColor, 
-      => @fire('hover', @index),
-      => @fire('click', @index),
-      => @fire('mouseout', @index)
-    )
+    if !/NaN/.test @hilight
+      @arc = @drawDonutArc(@hilight, @color)
+
+    if !/NaN/.test @path
+      @seg = @drawDonutSegment(
+        @path, 
+        @color, 
+        @backgroundColor, 
+        => @fire('hover', @index),
+        => @fire('click', @index),
+        => @fire('mouseout', @index)
+      )
 
   drawDonutArc: (path, color) ->
     if @options.animate

morris.js

@@ -2822,14 +2822,18 @@ Licensed under the BSD-2-Clause License.
 
     DonutSegment.prototype.render = function() {
       var _this = this;
-      this.arc = this.drawDonutArc(this.hilight, this.color);
-      return this.seg = this.drawDonutSegment(this.path, this.color, this.backgroundColor, function() {
-        return _this.fire('hover', _this.index);
-      }, function() {
-        return _this.fire('click', _this.index);
-      }, function() {
-        return _this.fire('mouseout', _this.index);
-      });
+      if (!/NaN/.test(this.hilight)) {
+        this.arc = this.drawDonutArc(this.hilight, this.color);
+      }
+      if (!/NaN/.test(this.path)) {
+        return this.seg = this.drawDonutSegment(this.path, this.color, this.backgroundColor, function() {
+          return _this.fire('hover', _this.index);
+        }, function() {
+          return _this.fire('click', _this.index);
+        }, function() {
+          return _this.fire('mouseout', _this.index);
+        });
+      }
     };
 
     DonutSegment.prototype.drawDonutArc = function(path, color) {