Segmentation Fault in xaccFreeSplit

[Matthew Vanecek]

On Fri, 2005-01-21 at 21:09 -0600, Matthew Vanecek wrote: 
> On Fri, 2005-01-21 at 11:37 -0800, Thomas Bushnell BSG wrote:
> > Derek Atkins <warlord at MIT.EDU> writes:

[snip]

> It's faulting on my P3 nowadays for some reason.  I wasn't sure if it
> was a glibc thing or what.  Quite annoying.  I was wondering if someone
> could reproduce this on his/her machine, to see if it's my machine/setup
> or something else.
> 
> I'm kinda skeptical about using the contents of a freed Split to see if
> the Split has been freed, though.  What if something else has
> overwritten the freed memory?  Why is that particular pointer guaranteed
> to still be == (char *)1 if the split is run through the function again?

Hmm, it was my debugging attempt causing the problem--can't *printf("%
s") on a char* field that's been set to (char *)1.  So, while accessing
the potentially freed memory is dubious, the SEGV actually happens a few
lines down, and a file or two over, in the qof_entity_release()
function.  My Bad(tm).  For some reason, split->entity.e_type is NULL by
this point, and I don't think the CACHE_REMOVE(str) macro appreciates
that.

This crash is happening on exit, when you would expect the memory to be
freed.


  PINFO("Fixing to release split entity for type: %s",
        split->entity.e_type);
  qof_entity_release (&split->entity);

causes this result:
 
Info: xaccFreeSplit(): Fixing to release split entity for type: (null)
CRASH!!!!!! (because qof_entity_release doesn't have an logging
statements...).

and the gdb bt revealed that some g_hash_something function burped on
the NULL value.  Don't have time right now to recreate the bt (bedtime)
but I could probably get to it again on Sunday.

Is it permissible for split->entity.e_type to be NULL at this point in
the game (exiting, etc.)?  It's probably something I've written causing
this, but when I save the Split, it's e_type is "Split", and then when I
exit, the e_type is NULL...

Thanks,

-- 
Matthew Vanecek
perl -e 'print $i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'
********************************************************************************
For 93 million miles, there is nothing between the sun and my shadow except me.
I'm always getting in the way of something...
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