Path: utzoo!mnetor!uunet!husc6!hao!boulder!sunybcs!rutgers!psuvax1!burdvax!wpl
From: wpl@burdvax.PRC.Unisys.COM (William P Loftus)
Newsgroups: news.software.b
Subject: Re: possible vn bug?
Message-ID: <5066@burdvax.PRC.Unisys.COM>
Date: 24 Dec 87 01:37:40 GMT
References: <222@jc3b21.UUCP>
Sender: news@burdvax.PRC.Unisys.COM
Distribution: na
Organization: Unisys/Paoli Research Center, Paoli, PA
Lines: 68

From article <222@jc3b21.UUCP>, by jra@jc3b21.UUCP (Jay R. Ashworth):
> While bopping along in vn, reading the news, (Thanks, bobm) I occasionally 
> get shot down by what appears to be a bug in the program.  To wit:
> If I attempt to read an article with a header line which is continued,
> e.g.:
> 
> Keywords: This is a test.
> 	  This is only a test.
> 
> the program bombs, after showing all the header lines (I have header
> display toggled off), with a floating exception, core dumped.  I note
> that when this happens, there is evident, intermixed with the headers,
> the line
> 
> Lines: 0
> 

I had fixed this bug in the previous version of vn (not the current release).
I guess the fix never made it into the developers codes (although, I did send
him a fix for the bug.).
The following text describes how the bug was fixed in the previous version of vn
NOT the current version.
--
I had a problem with vn.  Once in a while, vn would crash with a floating
point exception (divide by zero).  I tracked to bug to the following lines
of code in reader.c.

	/* for conditional is abnormal - expected exit is break */
	for (count = 0; count < HDR_LINES && fgets(buf,RECLEN-1,Fpread) != NULL; ++count)
	{

		/* reset position and bail out at first non-header line */
		if (index(buf,':') == NULL)
		{
			pos = ftell(Fpread);
			pos -= strlen(buf);
			fseek (Fpread,pos,0);
			break;
		}


Vn had thought the header ended when there was a line with no ':'. This is
a false assumption (I think), a header ends when there is a line that doesn't
begin with ' ' or '\t' and has no embedded ':'.
Below is the fix to the above code.


	/* for conditional is abnormal - expected exit is break */
	for (count = 0; count < HDR_LINES && fgets(buf,RECLEN-1,Fpread) != NULL; ++count)
	{

		/* reset position and bail out at first non-header line */
		if (index(buf,':') == NULL)
		{
                        if ((buf[0] != '\t') && (buf[0] != ' ')) {
				pos = ftell(Fpread);
				pos -= strlen(buf);
				fseek (Fpread,pos,0);
				break;
                        }
		}


-- 
William P Loftus			UUCP:   wpl@burdvax.UUCP
Unisys/Paoli Research Center		ARPA: 	wpl@burdvax.prc.unisys.com
PO Box 517				BITNET: 202527899@VUVAXCOM
Paoli, PA 19301                         215-648-7222 (work) 215-354-0614 (home)