SE Gutter better scroll tracking [Bugfix-20140]

[Niggemann, Bernd]

A very simple reproducible instance of the wandering red dot but only in LC 9 (tested in DP2, DP4 and DP8) is pasting.

make a button with

on mouseUp
   put x into y
   put y into v
end mouseUp

compile script

place the red dot at "end mouseUp"

now copy the body of the handler (2 lines)
and paste them after the existing 2 lines
watch red dot wander, repeat etc.

This kind of pasting does not make the red dot wander in 8.1.0 nor 8.1.5

Kind regards 
Bernd