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From: marcl@ESD.3Com.COM (Marc Lavine)
Newsgroups: comp.lang.perl
Subject: Perl 4.0.beta problems with undef
Message-ID: <marcl.668921376@cook.ESD.3Com.COM>
Date: 14 Mar 91 03:29:36 GMT
Sender: news@bridge2.ESD.3Com.COM
Lines: 63
Nntp-Posting-Host: cook.esd.3com.com

I've found that using "undef" on an element of an associative array
can cause Perl 4.0.beta to dump core (not neccessarily immediately).
I'm enclosing a short script (albeit somewhat strange) that should
allow others to confirm this.  I've run it on a SPARCstation SLC under
SunOS 4.1.1.  This script does not dump core under Perl 3.0.37 or
3.0.44.

	Marc Lavine


#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#		"End of shell archive."
# Contents:  undef.bug.pl
# Wrapped by marcl@cook.ESD.3Com.COM on Wed Mar 13 19:46:31 1991
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'undef.bug.pl' -a "${1}" != "-c" ; then 
  echo shar: Will not clobber existing file \"'undef.bug.pl'\"
else
echo shar: Extracting \"'undef.bug.pl'\" \(403 characters\)
sed "s/^X//" >'undef.bug.pl' <<'END_OF_FILE'
X#!/usr/local/bin/perl
X#
X# Demonstrate a bug in Perl 4.0.beta.
X# This script works fine under Perl 3.0.37 and 3.0.44.
X# Under 4.0.beta, Perl dumps core.
X#
X
X$count = 2;
X
Xwhile ( $count-- )
X    {
X    open ( INPUT, "undef.bug.pl" );
X
X    while ( <INPUT> )
X	{
X	$lines { $counter++ } = $_;
X	undef $lines { $counter };
X	}
X
X    while ( --$counter )
X	{
X	undef $lines { $counter };
X	}
X
X    close ( INPUT );
X    }
END_OF_FILE
if test 403 -ne `wc -c <'undef.bug.pl'`; then
    echo shar: \"'undef.bug.pl'\" unpacked with wrong size!
fi
chmod +x 'undef.bug.pl'
# end of 'undef.bug.pl'
fi
echo shar: End of shell archive.
exit 0
--
Marc Lavine		    	Broken: marcl%3Com.Com@sun.com
Smart: marcl@3Com.Com	    	UUCP: ...{sun|decwrl}!3Com.Com!marcl