[Kstars-devel] Crash, possibly related to line clipping

[James Bowlin]

On Sun June 29 2008, Akarsh Simha wrote:
> I encountered a crash while using KStars today. Unfortunately, I was
> unable to reproduce it.
>
> I'm not yet acquainted with interpreting backtraces, but the
> backtrace seems to hint that this is a problem with line clipping. Is
> it a bug in Qt's libraries or our application? Could someone help me
> here?
>
> I've attached the backtrace.

I think this is a problem in QT although it is possible we are sending 
QT bad data that triggers the crash (although no data should be so bad
as to cause a crash like this).  The transition from our code to their 
code in the backtrace occurred here:

#24 0x080941ee in QPainter::drawLine ()
#25 0x08094221 in QPainter::drawLine ()
#26 0x0809b5e9 in LineListIndex::drawLines ()
#27 0x0809b7bc in LineListIndex::draw ()

I suspect this crash might be related to the slowdown we encountered 
when the coordinate grid is enabled at high zoom levels.  We have 
encountered trouble before with QT's built-in line clipping that
caused us to code around bugs in the QT code.


-- 
Peace, James