Has anybody come across the following behavior...

When I run this code: 

use Data::Dumper;
my $re_bad  = qr'@@([A-Z$#@_#]*) (?! [A-Za-z0-9$#@_] )'x;
print Dumper $re_bad;

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using Perl v5.8.0 (on Solaris), I get the following output: 
$VAR1 = qr/(?x-ism:@@([A-Z$#@_#]*) (?! [A-Za-z0-9$#@_] )$
)/;

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Notice the spurious characters at the end of the regex. Using Perl v5.6.1, the output is as expected: 
$VAR1 = qr/(?x-ism:@@([A-Z$#@_#]*) (?! [A-Za-z0-9$#@_] ))/;

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The only reason I noticed this is that the regex I was actually using was such that the characters scribbled onto the end were **, resulting in an invalid regex. So, I can imagine that this error would go undetected for some time. NB The issue is not with Data::Dumper. I just used that to illustrate. It appears that Perl is actually writing extra characters onto the regex. Obviously, I will report the bug, but I wanted to see if anybody else had come across it. This will stop us migrating to 5.8.0 unless we can find an acceptable workaround.

Cheers, Kevin

In reply to Worrying regex issue with 5.8.0 by ruscoekm

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