The problem is that your regex potentially matches zero characters, so a loop like 

while (/\s*/g) {
    ...
}

[download]

Would loop infinitely. To prevent that, perl has some extra magic asociated with zero-width matches and /g, which you observe here. The obvious solution is to not use a regex which can match zero characters. You can prevent resetting of pos by using the /gc modifiers.

Perl 6 - the future is here, just unevenly distributed

In reply to Re: [Perl 5.14, regex]: Problems with /g, \G and pos() by moritz
in thread [Perl 5.14, regex]: Problems with /g, \G and pos() by Darkwing

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