[Development] Backporting the Keccak change

[Oswald Buddenhagen]

On Tue, Sep 05, 2017 at 10:29:44AM -0300, Thiago Macieira wrote:
> On Tuesday, 5 September 2017 05:09:19 -03 Oswald Buddenhagen wrote:
> > #  ifndef QT_FIXED_SHA3
> >        QT_DEPRECATED_SINCE(5, 10, 0) Sha3_224 = 7,
> >        QT_DEPRECATED_SINCE(5, 10, 0) Sha3_256,
> >        QT_DEPRECATED_SINCE(5, 10, 0) Sha3_384,
> >        QT_DEPRECATED_SINCE(5, 10, 0) Sha3_512,
> > #  else
> 
> Almost. There are two things there:
>  1) I'dl ike people to opt into the broken code, so I think the #if should be 
> reversed. It will cause a few support tickets and bug reports, but I think 
> it's best this way for the long term. At some point, we'd have to do it 
> anyway.
> 
well, i know that you'd like to, but it's still breaking the compat
promise for no _really_ convincing reason.
while the current implementation is clearly broken, it apparently works
well enough for those who use it, and the others don't use it anyway
(obviously). so the idea is to not fix the problem, but to do an, ehhm,
"specification update". ;)

there isn't really much added value to making the wrong behavior opt-in,
because the user can then just use the new enum values straight away.

>  2) you can't use QT_DEPRECATED or Q_DECL_DEPRECATED on enumerations
>  unless __cpp_enumerator_attributes >= 201411
> 
i sort of expected that. how about a separate macro for enums, to avoid
an ifdef mess? maybe we have it already?