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Re: [perl #115910] New copy-on-write breaks CPAN

From:
Leon Timmermans
Date:
December 19, 2012 21:06
Subject:
Re: [perl #115910] New copy-on-write breaks CPAN
Message ID:
CAHhgV8gu4vq9ZXE0y31QC9YEyyhSAF4hvrWGgHBpXLgMXTCz1Q@mail.gmail.com
On Wed, Dec 19, 2012 at 2:55 PM, Father Chrysostomos via RT
<perlbug-comment@perl.org> wrote:
> That logic probably needs to be revisited then.  Is the s/// target a
> COW before the substitution?  (You don’t need to CC me.)

No, it's a SvLEN == 0 string, with set magic as fallback to ensure the
SvPVX keeps pointing into the memory map. The fallback however is
wildly inefficient as it needs to copy the copy, hence the warning.
It's there to prevent data-loss and segfaults, not to be used
intentionally.

Leon



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