Even so, the pointer should have been initialised to 0 or NULL in the 
initializer list. Leaving pointers to contain junk is never a good idea.

On 6 Dec 2009, at 17:59, Gilles Valette wrote:

> Message de Danny Price <[email protected]>:
> 
>> Always use initializer lists.
>> 
> 
> He can't because this call is not made in a constructor but in a slot  
> corresponding to a button click, and a new thread is created at each  
> click. I am not saying that it is the best way to do it (I actually do  
> not know the goal of the code...), I was just answering to the  
> question about the segfault in the given code.
> 
> Regards,
> 
> Gilles
> 
>> On 6 Dec 2009, at 13:39, Gilles Valette wrote:
>> 
>>> Message de Soumen banerjee <[email protected]>:
>>> 
>>>> In the files attached, mainwindow.cpp has the following line
>>>> 
>>>> connect(ptr,SIGNAL(setlabel(int)),this,SLOT(setLabel(int)));
>>>> 
>>>> where ptr is of type mythread* which is derived from QThread
>>>> the application compiles without error but on running, quits with
>>>> segfault. Omitting the connect line solves the problem but removes all
>>>> the functionality. How do you connect these together?
>>>> Regards
>>>> Soumen
>>>> 
>>> 
>>> Hi,
>>> 
>>> In mainwindow.cpp when you call connect, ptr is undefined, causing the
>>> segfault.
>>> 
>>> Putting the two lines in this order solves the problem :
>>> 
>>>    ptr=new mythread(this);
>>>    connect(ptr,SIGNAL(setlabel(int)),this,SLOT(setLabel(int)));
>>> 
>>> Hope this helps.
>>> 
>>> Gilles
>>> 
>>> 
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> 
> 
> 
> -- 
> Gilles VALETTE - PhD
> Maître de conférences en informatique - IUT de Reims
> Université de Reims Champagne-Ardenne (URCA) - CReSTIC EA3804
> Rue des Crayères, BP 1035 51687 Reims Cedex 2 (France)
> Tel: +33 (0)3 26 91 84 58
> http://www.crestic.univ-reims.fr/fiche.php?id=216
> 
> 
> 
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