Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!soliloquy!eb
From: eb@soliloquy.uucp (Ed Blackmond)
Newsgroups: news.software.b
Subject: Re: possible vn bug?
Message-ID: <33360@soliloquy.uucp>
Date: 24 Dec 87 17:16:35 GMT
References: <222@jc3b21.UUCP>
Distribution: na
Organization: Sun Microsystems, Inc. - Mtn View, CA
Lines: 38
Keywords: vn core dump floating exception 2-line headers
Summary: percent calculation bug

In article <222@jc3b21.UUCP>, jra@jc3b21.UUCP (Jay R. Ashworth) writes:
> 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.
>  ...
> .  Since the "core" doesn't "dump" until the end of the screen, could
> this problem be triggered by the percent left code in the builtin
> pager?  The bug also appears to slightly mung the .newsrc table, as
> after it happens, I get articles back to read again.
> 
I got this too and as you suspect it is related to the
percent calculation at the end of the page.  I just hacked
it to not do the division if it thinks there are zero lines
in the article.  This gives bogus percentages for these
articles but I don't really care.

The problem is in the function readline() in the file
reader.c  Here is the code I use now (sorry I forgot to
check it into RCS before hacking on it so I don't have a
diff):
---
reader.c 196 - 205
                       /*
                        ** calculation is truncated rather than rounded,
                        ** so we shouldn't get "100%".  Subtract 2 for
                        ** 1 line lookahead and empty line at beginning
                        ** of article.
                        */
                        if (Headflag || artlin == 0)
                                percent = ((Rlines-2)*100)/(artlin+Hlines);
                        else
                                percent = ((Rlines-Hlines-2)*100)/artlin;
---
I added the "|| artlin == 0" test.
-- 

Ed Blackmond		Disclaimer: The above opinions are those of the
Sun Microsystems	     author and should be considered the gospel
sun!soliloquy!eb	     truth.  ( cat Mathew/5:48 | sed s/you/I/ )