[Lazarus] IDE Editor incredibly slow on newer GTK2

[Bernd]

2012/3/24 Martin <lazarus at mfriebe.de>:

> Weird.
>
> How about, if there is a horizontal scrollbar, but not a vertical?

I can now reproduce it with a synedit in my own application. It seems
it needs both scrollbars.

none or only one scrollbar: sluggish, high CPU
both scrollbars: smooth.

It also seems to have something to do with eoScrollPastEOL, my synedit
test-app became slow after I set this to False. (This also makes
scrollbars disappear in small documents when ssAutoBoth but it almost
seems to me this setting also has an additional effect on the CPU
usage even if scrollbars are already present)