#!/usr/bin/perl -w
use strict;
use warnings;

while (defined(my $line = <DATA>) )
{
    chomp $line;                        # line 7
    if ($line =~ s/\\$//)               # line 8
    {
        $line .= <DATA>;
        redo unless eof(DATA);
    }
    print "LINE: '$line'\n";
}

__DATA__
1 1
2 2
3 3
4 4 \
 4 4 \
  4 4
5 5

##</code><code>##

skx@gold:~$ ./bug.pl 
LINE: '1 1'
LINE: '2 2'
LINE: '3 3'
LINE: '4 4  4 4   4 4'
LINE: '5 5'
LINE: ''
skx@gold:~$ perl -v|grep perl,
This is perl, v5.10.0 built for x86_64-linux-gnu-thread-multi

##</code><code>##

steve@skx:~$ ./bug.pl 
LINE: '1 1'
LINE: '2 2'
LINE: '3 3'
Use of uninitialized value in scalar chomp at ./bug.pl line 7, <DATA> line 5.
Use of uninitialized value in substitution (s///) at ./bug.pl line 8, <DATA> line 5.
Use of uninitialized value in concatenation (.) or string at ./bug.pl line 13, <DATA> line 5.
LINE: ''
LINE: '  4 4'
LINE: '5 5'
LINE: ''
steve@skx:~$ perl -v | grep perl,
This is perl, v5.8.8 built for i486-linux-gnu-thread-multi