wax.mm.js mouseover interactivity error

[nateirwin]

When I updated to the latest version of Wax (3.0.8 - 1.0.4-403-ge99ff67), I noticed that I was getting an error when mousing over the map when a layer or multiple layers with interactivity were added to it. I traced the problem back to line 379 of "wax.mm.js":

if (grid_tile.keys[key] && grid_tile.data[grid_tile.keys[key]]) {

grid_tile was sometimes undefined. Checking to make sure it is undefined solves the problem:

if (grid_tile && grid_tile.keys[key] && grid_tile.data[grid_tile.keys[key]]) {

although I'm sure there is something wrong on down the line somewhere, so this probably isn't a solution to the underlying problem.

[nateirwin]

A little more info about this. The error seems to occur when the mouse is over or close to HTML elements that are absolutely positioned over the map. I'm having a hard time reproducing this consistently, though.

[tmcw]

Hmm. In new builds, I've added the extra check you suggest to avoid the error, but it definitely is something deeper - possibly just pulling blank grid tiles but still going through that bit of the code. Keeping open.