Merge pull request #1622 from twpayne/fix-circle-containsxy

Fix bug in ol.geom.Circle#containsXY, thanks @vdubr

src/ol/geom/circle.js

@@ -72,7 +72,7 @@ ol.geom.Circle.prototype.containsXY = function(x, y) {
   var dx = x - flatCoordinates[0];
   var dy = y - flatCoordinates[1];
   var r = flatCoordinates[this.stride] - flatCoordinates[0];
-  return dx * dx + dy * dy <= r;
+  return Math.sqrt(dx * dx + dy * dy) <= r;
 };