do not redefine minPos and maxPos functions for bars with period

Author: archmoj

src/traces/bar/hover.js

@@ -156,7 +156,7 @@ function hoverOnBars(pointData, xval, yval, hovermode, opts) {
     // if we get here and we're not in 'closest' mode, push min/max pos back
     // onto the group - even though that means occasionally the mouse will be
     // over the hover label.
-    if(!isClosest) {
+    if(!isClosest && !period) {
         minPos = function(di) {
             return Math.min(thisBarMinPos(di), di.p - t.bargroupwidth / 2);
         };