Selection box stays after panning

[destradafilm]

I see an issue when I draw a selection box on the points on a scattergl plot, and then I pan.

After I select a range of points and then I use the modifier key 'alt-select' (to subract) or 'shift-select' (to add) I can see the previously drawn selection box and it has not moved even though the plot has shifted range.

EXAMPLE:
http://recordit.co/Z6r2ZPUMoo

Also, I can't find documentation about the modifier key 'add-select' or 'subtract-selection' tools.
Is there a dragmode: 'select-add' or a way to programmatically use these dragmodes?

[etpinard]

Ha. Nice catch @destradafilm thanks for the report.

This bug is similar to #2667 (the optimizations of bb02281 are likely to blame) but will require another patch.

I'll try to squeeze that one in before 1.38.1 .