AW: Re: LyX/Q.../Free crash

[michael.gerz@teststep.org]

>> src/kernel/qfontdatabase.cpp, line 913, reads
>> 
>>   fe = loadEngine(script, fp, request, 0, 0, 0 );
>> 
>> loadEngine() is defined in file src/kernel/qfontdatabase_win.cpp which
>> expects a QFontFamily as fourth parameter. Within loadEngine() (line
>> 337), family->rawName.lower() is evaluated. However, we get a
>> segmentation fault since we explicitly pass 0 as parameter.
>> 
>Angus already told me about this crash but had no time to go deeper.
>Afais it's your fault because qfontdatabase_x11.cpp and
>qfontdatabase_win.cpp (qt4) also don't like NULL there... but it should
>be no problem to check for != NULL.

Well, qfontdatabase.cpp, line 913, passes NULL explicitly to loadEngine. Thus, it is not LyX but Q.../Free that causes the crash. However, LyX may cause an execution path that does not occur "normally". 

Could you please check whether qfontdatabase.cpp (Qt4) also passes "0" as fourth parameter to loadEngine? Of course, we could just add a check for 0 in loadEngine and be happy but it may also have some unknown side-effects.

>> PS: I also encountered a problem with resizable dialogs. Qt responds
>> very sluggish and sometimes it forgets to redraw the dialog. A couple of
>> months ago (before the big Qt mergers?) Q.../Free worked much better in
>> this case.
>I hit this problem too, but currently had no time to see what's going
>wrong. I already have a small testcase and hope to fix it asap.

Fine!

Michael