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Date: Sat, 11 Aug 2018 10:38:42 -0500
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To: "Christoph M. Becker" <cmbecker69@gmx.de>
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Subject: Re: The curious case of the comparable objects.
From: pollita@php.net (Sara Golemon)

On Sat, Aug 11, 2018 at 8:34 AM, Christoph M. Becker <cmbecker69@gmx.de> wr=
ote:
>> 2. Is it a bug introduced in 5.4 that's okay to fix? Or would fixing
>> it count as a BC break due to how long it's been broken? (I say
>> fixable bug, the BC break was at 5.4)
>
> I tend to agree, even though the behavior is not really documented.  The
> php.net manual says nothing about the ordering of objects, and the
> language specification isn't clear about that, since it refers to array
> comparison[1], but doesn't define the order of the properties.  Are
> properties of parent classes inserted before the properties of child
> classes?  Are ad-hoc properties inserted after the predefined ones?  Are
> trait properties inserted where the are =E2=80=9Cuse=E2=80=9Dd?  Are invi=
sible
> properties also part of the comparison?
>
> [1]
> <https://github.com/php/php-langspec/blob/master/spec/10-expressions.md#u=
ser-content-relational-operators>
>
Yeah, that's why I'm hesitant on just slapping a bug fix on it and
apply to 7.1+ without asking for input.  If this were a younger
regression I might just do it and move on, but 5.4-7.2 is a six
release branches.

FWIW, objects with ad-hoc properties are not impacted by this since
they automatically have a HashTable for their properties. This only
impacts fully defined classes (the best kind) who have not had their
shadow table materialized (also the best kind).

PR, by the way: https://github.com/php/php-src/pull/3434

-Sara