Re: [PATCH v2 3/4] Makefile: really use and document sha1collisiondetection by default

[Junio C Hamano <gitster@pobox.com>]

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

> There's things I can eject from this series, but I don't really find it
> to be "while at it" changes, I suspect what you're thinking of is
> one/some of:
>
>  - Re-arranging the Makefile commentary into sections: I did that
>    because now the structure is very much one-paragraph-per-flag. 

And it does not have anything to do with "why doesn't macOS use
sha1dc as the default like everybody else?" fix.

>  - We're still claiming that we use OpenSSL by default, so I fixed the
>    docs in general (not just the Makefile). Would you like this to be
>    just a "we forgot OSX?" series?

A focused change s/We use OpenSSL as default/We use sha1dc as default/ 
goes well with "why doesn't macOS use sha1dc as the default?" fix.

>  - Ditto asking to provide NO_DC_SHA1=Y now in addition to

Those who explicitly opt into DC_SHA1 do not need any new $(error).
Those who have explicitly chosen something else should not be forced
to say NO_DC_SHA1.

Let's make it a focused change that does one thing very well without
wasting reviewer's time on discussion on non-essential things.

I do not mean by "non-essential" that reorganizing Makefile comments
to make it easier to find and write relevant documents, or making it
harder to turn conflicting knobs.  They may by themselves be
worthwhile thing to do.  But in the context of "why isn't sha1dc the
default everywhere", they are non-essential distractions.

"why isn't sha1dc the default on macOS?" is also non-essential
distraction in the context of fixing "oops, we no longer build on
macOS unless Apple Crypto is used".

I've queued [1/4] with an intention to fast-track it down to
'master' (after cooking it in 'next' for a few days).

Thanks.