Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!sun!pitstop!sundc!rlgvax!dennis
From: dennis@rlgvax.UUCP (Dennis.Bednar)
Newsgroups: comp.sources.d
Subject: gnu egrep - realloc of 0 bytes caused failure: Memory exhausted
Message-ID: <1114@rlgvax.UUCP>
Date: 15 Feb 89 08:32:13 GMT
Organization: Computer Consoles Inc, Reston VA
Lines: 25

The GNU version of egrep failed to work on a CCI 6/32
running Unix SV.  The bug was traced to the fact that
realloc(p, n) was being called with n==0, given the
command line "grep abc".  I did not have time to track
down the gory details as to why realloc was being called
with 0, nor why it supposedly works on other machines
(assuming that realloc is called with 0 on other machines).

To fix the problem temporarily, in dfa.c, in the function
xrealloc(), change:
  ptr_t r = realloc(p, n);
to
  ptr_t r = realloc(p, ( n ) ? n : 50);
so that a dummy 50 byte realloc would be done if the size
were zero.  Without the change, our realloc() library routine
was returning char *NULL, causing a "Memory exhausted" message.

Comments from the authors?

-dennis
-- 
FullName:	Dennis Bednar
UUCP:		{uunet|sundc}!rlgvax!dennis
USMail:		CCI; 11490 Commerce Park Dr.; Reston VA 22091
Telephone:	+1 703 648 3300