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Date: Mon, 15 May 2017 17:12:09 +0700
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To: Nicolas Grekas <nicolas.grekas@gmail.com>
Cc: "internals@lists.php.net" <internals@lists.php.net>
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Subject: Re: [PHP-DEV] BC break in master (7.2) - Distinguish between
 unmatched subpatterns and empty matches in preg_*()
From: pierre.php@gmail.com (Pierre Joye)

hi Nicolas,

On Mon, May 15, 2017 at 1:57 PM, Nicolas Grekas
<nicolas.grekas@gmail.com> wrote:
> Hi,
>
> in master, feature request https://bugs.php.net/61780 has been implemented
> and merged into master thanks to https://github.com/php/php-src/pull/1303
>
> But as noted in the PR and even in the UPGRADING file, this is a BC break:
>   . preg_match() and other PCRE functions now distinguish between unmatched
>     subpatterns and empty matches by reporting NULL and "" (empty string),
>     respectively. Formerly, either was reported as empty string.
>
> While trying to run Symfony's test suite against 7.2, we noticed that this
> BC break is hitting several components badly. If Symfony is hit, there will
> be many more userland code impacted for sure.
>
> As written explicitly in the releasing policy of php-src, BC breaks must
> not happen in minor versions. Therefore, I'm kindly but strongly asking for
> this BC break to be reconsidered and removed.

I agree that a minimum 5 years old possible bug, quite small, causing
BC breaks is not good. As far as the fix is critical or justified, I
think it is sometimes ok to break BC for edge cases. However I do not
see this is not the case here.

@RMs revert for 7.2 and re evaluate for later?

Cheers,
-- 
Pierre

@pierrejoye | http://www.libgd.org