Groff Bug Report

[Ken Chilton]

GROFF VERSION:
1.18.1 and 1.19.1
(Prior version 1.16.1 appears to work fine)

MACHINE:
i386 (AMD Athlon(tm) Processor stepping 02, Irongate chipset)

OS:
Linux 2.6.10-1.741_FC3 #1 Thu Jan 13 16:38:22 EST 2005 i686 athlon i386 
GNU/Linux

COMPILER:
gcc version 3.4.2 20041017 (Red Hat 3.4.2-6.fc3)

INPUT FILES:
I'll ignore the instructions, for now.  The problem should be obvious. ;)

COMMAND LINE:
grops chapter1.t chapter2.t > paper.ps

DESCRIPTION OF INCORRECT BEHAVIOUR:
*** glibc detected *** double free or corruption (fasttop)
Using Fedora Core 3 (latest release, fully upgraded), I encountered the error.  
This release of Fedora uses a new glibc which does not allow one to perform a 
free() on the same location twice.  (Since glibc-20040925T0738, released in 
glibc 2.3.4)
The error arises with any two input files I select, but I have not found a 
single file which will produce the error alone.

SUGGESTED FIX [optional]:
Clear all pointers to NULL after a free.  Test all pointers against NULL before 
clearing.  e.g.:
if(pointer) free(pointer);
pointer=NULL;

Or, maybe you would like to find where this is happening (if you care):
if(pointer) free(pointer);
else fprintf(stderr,"Attempted to double free at Checkpoint A-354\n");
pointer=NULL;



Thanks,
KC