TouchExtend brakes map dragging

[johnd0e]

How to reproduce

• Leaflet / Draw versions are same as in official examples
• Browser (with version) I'm using: Google Chrome 74.0.3729.157 (Official Build) (32-bit)
• OS/Platform (with version) I'm using: Windows 10 (32-bit)

What behaviour I'm expecting and which behaviour I'm seeing

When in polyline/polygon drawing mode it's possible to drag the map, but besides of dragging every click makes new point, which is undesirable.

It's possible to fix this by disabling touch handler (map.touchExtend.disable()).
After this:

• we can drag safely, without making unneeded points
• we still can make new points with simple clicks (without dragging)

Unfortunately with disabled handler we lost 2 abilities

• draw circle/rectangle on touch device
• draw anything with mouse attached to touch device

I suppose we need to completely revise TouchEvents.js, as there are too many bugs (see Issues)

Minimal example reproducing the issue

https://leaflet.github.io/Leaflet.draw/docs/examples/full.html

[johnd0e]

Seems same issue as #695, #729

[johnd0e]

Fix:

  L.Draw.Polyline.prototype._onTouch = L.Util.falseFn;

Note:
Make sure that L.Map.Tap handler is not enabled.