[Lazarus] IDE Editor incredibly slow on newer GTK2

[Bernd]

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

> Compile the SynEdit package with the following defines
> SynDebug
> SynCaretDebug
> SYNSCROLLDEBUG
> VerboseSynEditInvalidate
> SynCheckPaintLock
>
> and get a logfile.
>
> Please also try if switching the overview gutter (right hand site)
> (Options/Editor/Display) makes a different.  IIRC some WS does unnecessary
> invalidates (but not as bad as you described)
>
> Or switch off highlight of all occurrences of the word under caret
> (obviously that can lead to a full invalidate, but usually it has a time
> delay, so it does not affect editing)

I will try these defines and make the log (tomorrow). The right
overview gutter (and also the left gutter) does not have any notable
effect.

Meanwhile I have made another interesting discovery: It only happens
when there is *no* horizontal scrollbar. As soon as the horizontal
scroller appears the CPU usage of the X server immediately drops from
60% to 20%, total CPU usage well below 100% and the caret is moving
smoothly again and no notable delay. This is why I noticed it only
today and not 2 weeks ago: I started a new project today and the unit
where I spent most of my time today does not have long enough lines
yet to have a horizontal scrollbar.