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Date: Thu, 13 Mar 1997 13:00:02 -0800 (PST)
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From: Gareth McCaughan <gjm11@dpmms.cam.ac.uk>
Subject: Re: bin/2968: fmt dumps core on ^M 
Reply-To: Gareth McCaughan <gjm11@dpmms.cam.ac.uk>
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The following reply was made to PR bin/2968; it has been noted by GNATS.

From: Gareth McCaughan <gjm11@dpmms.cam.ac.uk>
To: freebsd-bugs@freebsd.org
Cc:  Subject: Re: bin/2968: fmt dumps core on ^M 
Date: Thu, 13 Mar 1997 18:47:53 +0000

 Robert Eckardt wrote:
 
 > 	fmt experiences Bus error when one tries to format
 > 	a text that contains ^M (CRs), i.e. e.g. from an
 > 	MSDOS system.
 
 Actually, that's not quite true. I think it only happens if you
 invoke it with a file whose first line contains only non-printing
 characters.
 
 The problem is caused by the fact that, when a line of this kind is
 seen, the |canonb| pointer may not get initialised; as a consequence
 the loop
     for (cp2--; cp2 >= canonb && *cp2 == ' '; cp2--)
 (before the start of which |cp2==canonb| in this situation) loses
 because pointers are compared as if they're unsigned.
 
 I believe the following patch fixes the problem. It certainly
 looks OK and repairs the test cases I've tried.
 
 ---------- patch begins ----------
 *** fmt.c.orig	Thu Mar 13 10:57:48 1997
 --- fmt.c	Thu Mar 13 18:43:13 1997
 ***************
 *** 147,153 ****
   	register char *cp, *cp2, cc;
   	register int c, col;
   #define CHUNKSIZE 1024
 ! 	static int lbufsize = 0, cbufsize = 0;
   
   	if (center) {
   		linebuf = malloc(BUFSIZ);
 --- 147,157 ----
   	register char *cp, *cp2, cc;
   	register int c, col;
   #define CHUNKSIZE 1024
 ! 	static int lbufsize = 0, cbufsize = CHUNKSIZE;
 ! 
 ! 	canonb = malloc(CHUNKSIZE);
 ! 	if (canonb == 0)
 ! 		abort();
   
   	if (center) {
   		linebuf = malloc(BUFSIZ);
 ----------- patch ends -----------
 
 -- 
 Gareth McCaughan       Dept. of Pure Mathematics & Mathematical Statistics,
 gjm11@dpmms.cam.ac.uk  Cambridge University, England.