[Texmacs-dev] Re: Experimental Qt port

[Abdelrazak Younes]

On 02/10/2008 14:53, address@hidden wrote:
> I've done some testing on current cvs texmacs and the situation is the
> following:
>
> - linking with qt4.4.3 release version leads to crash (gdb session
> attached below).
> - linking with qt4.4.3 debug version works fine
> - linking with qt4.3.5 debug or release works fine
>
> So current hypothesis is that it is a problem with the release version
> of 4.4.3. Moreover I just commited some patches which should allow
> correct visualization of characters under Linux (at least for me works
> on Red Hat Enterprise with Linux 2.6.9-78.0.1.ELsmp)

The problem is that a statusbar update is asked while in a paint event 
(see relevant backtrace snippet below). Older version of Qt did not 
complained but Qt4.4 changed the way child widgets are painted. We had 
the same crash in LyX when Qt4.4 was released. The solution was simply 
to remove the statusbar update call in the paint event. As a general 
rule, don't do any painting (even onto a pixmap) inside a paint event.

Hope this helps,
Abdel.

#58 0x00bae4b5 in QWidget::repaint (this=0x93aec10, address@hidden) at 
painting/qbackingstore.cpp:1140
#59 0x00a342c5 in QWidget::repaint (this=0x93aec10) at 
kernel/qwidget.cpp:8933
#60 0x00df44b6 in QStatusBar::reformat (this=0x93aec10) at 
widgets/qstatusbar.cpp:530
#61 0x00df4d6a in QStatusBar::event (this=0x93aec10, e=0x9726e48) at