Re: XForms: Wierd Seg Fault..

Steve Lamont (spl@szechuan.ucsd.edu)
Wed, 16 Sep 98 19:00:12 PDT

# To subscribers of the xforms list from spl@szechuan.ucsd.edu (Steve Lamont) :

> well I had dmalloc (not the same as dbmalloc?) and I installed it and
> linked the library to my file. Now, the error does not happen. There is no
> segfault, and I hadn't changed the code what so ever. howver, if I remove
> the linking in of the dmalloc lib, she fails at the same point.

Congratulations. You have a "Heisenbug." A Hiesenbug is a bug that
moves around or goes away when you change unrelated code (for example,
adding an fprintf() or using a different memory allocation library).
This convinces me even more that you are overrunning an array or
something of that nature.

Does dmalloc report out of bound memory references? How about freeing
the same block twice or using a pointer after you've freed it?

Another thing to look at is inadvertently freeing an automatic
variable.

spl
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