Update MarkerClusterGroup.js

[OriginalSin]

Use this._maxZoom instead map.getMaxZoom() in _zoomOrSpiderfy.
When we use disableClusteringAtZoom in options this._maxZoom not equal map.options.maxZoom.

[ghybs]

Hi!

You are right, it previously used map.getMaxZoom() === map.getZoom() and I just re-used map.getMaxZoom().

But since I merged the cases when all markers are at the exact same position and when we are at maxZoom, I accidentally removed spiderfication of markers at the exact same position when disableClusteringAtZoom is used with a lower zoom than map.options.maxZoom, as you point out.

For the case of markers at "slightly different positions", it could still be interesting to zoom rather than spiderfy, because the map has more zoom levels to separate out those markers. But they will not necessarily separate a lot!

So spiderfying with checking this._maxZoom rather than map.options.maxZoom sounds a reasonable choice, especially with the fact that application developer can still tune the behaviour with spiderfyOnMaxZoom option.

[danzel]

Cool 👍