[bt-devel] SegFault in 2.3.3 during navigation

[Gary Holmlund]

I looked at this for some time. I believe it is safe to copy the pointer 
for now.

The real problem here is where multiple classes use the same pointer to 
a verse reference. For instance, the CKeyReferenceWidget which 
implements the spinboxes for book, chapter, and verse. It keeps a copy 
of this pointer, increments it when the user changes the widget, and 
emits a signal for a verse change. The signal for verse change is caught 
by CBibleKeyChooser where it emits a beforeKeyChange using the same 
shared pointer. It does not know that the value in the pointer has 
already been changed. It then saves the pointer and emits a keyChanged 
with the saved pointer thinking that the second emit has a different 
value. This lead to problems in the saving of text in personal 
commentaries. Also, keeping a pointer as a member of multiple classes 
clearly can cause problems if any class decides to delete and recreate 
the pointer.

I think the real answer is to eliminate the use of a shared pointer for 
verse references. Each class should have a method of getting the verse 
reference value gets a non-pointer copy of the verse reference. All of 
the emit signals should pass a const reference to a verse value rather 
than the shared pointer. Doing this may take some time and perhaps 
should not be done as we are getting ready to make a release.

Gary

Martin Gruner wrote:
> Eeli,
>
> I just looked at the "fix" in r1726. It seems kindof dangerous to just copy the 
> key object, introducing a memory leak. I would guess that this only masks the 
> original crash problem instead of fixing it, but I cannot tell for sure now.
>
> I don't have the time now to investigate it, will be away until Monday.
>
> mg
>
> Am Mittwoch, 4. November 2009 17:10:12 schrieb Eeli Kaikkonen:
>   
>> On Wed, 4 Nov 2009, John A. Sullivan III wrote:
>>     
>>> Hello, all.  It's great to be able to use BibleTime once again.
>>> However, I am experiencing a readily reproducible segfault after
>>> upgrading to 2.3.3 via an apt-get update on fully patched Ubuntu 8.04 on
>>> 64-bit AMD.  If I scroll forward a chapter using the next chapter
>>> navigation arrows in my Bible pane and then click on a verse lower down
>>> in the text, I get a segmentation fault every time.
>>>       
>> This has accidentally been fixed with svn r1726 while fixing another
>> crash. It should be backported to 2.3 series.
>>
>>     
>>> I also noticed this wiped out any bookmarks I had created.  I looked for
>>> a way to save the bookmarks other than quitting BibleTime as a way to
>>> protect my work from this bug.  Perhaps I didn't look hard enough but I
>>> did not see a way. Is there a way to save bookmarks from within a
>>> session? Should they be save automatically upon creation so they are not
>>> lost in the event of a crash? Thanks - John
>>>       
>> That's a reasonable request (saving automatically), but could you add it
>> to our feature request database in sourceforge.net?
>>
>>   Yours,
>> 	Eeli Kaikkonen (Mr.), Oulu, Finland
>> 	e-mail: eekaikko at mailx.studentx.oulux.fix (with no x)
>>
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>
>