Re: GIT: Monotonically increasing trunk and release branch ids

[Jakub Jelinek <jakub at redhat dot com>]

On Fri, Jan 10, 2020 at 02:15:30PM -0500, Jason Merrill wrote:
> Yep, this is a lot like I was suggesting at
> 
>    https://gcc.gnu.org/ml/gcc-patches/2019-08/msg01015.html
> 
> except I didn't think it was necessary to trim the trailing SHA.  I
> also suggested creating a tag for the beginning of time to use in
> naming your compiler binaries.

In some spots, I think including both the rNN-NNNN and following -gNNNNNNNNN
would make a lot of sense, e.g. I think if that form went in the
commit mail body that is added into the bugzilla PRs.  Say
git describe --all --abbrev=40 --match 'branchpoints/gcc-[0-9]*' origin/master | sed 's,^tags/branchpoints/gcc-,r,'
r10-5824-g42950b74c9b103676f99dc9f1a27859e3f7be436
and let bugzilla and redirector handle that form and directly use
just the hash part of it for gitweb.  I think we should use for that
the 40 digit hashes, not just 7, there we'd risk they might not be unique
over time, right?
But e.g. for the commit mail subjects where space is precious, or I think
even for the bisect seed filenames, I think using just the part without
the hash when we have a way to get the hash back when needed is better.

> At https://gcc.gnu.org/ml/gcc-patches/2019-09/msg01211.html I
> suggested the prefix "g:".

Ah, you suggested g: rather than just g.
We could then support
rNNNNN (1-6 decimal digits) - the svn revs, either for old repo, or transformed
g:XXXXX (X is any [0-9a-zA-Z_-], something else?, 1 or more chars) - gitweb with XXXXX
rNN-MMMMM (1-2 decimal digits, 1-6 decimal digits) - git undescr to hash
rNN-MMMMM-gXXXXX (perhaps limit X to hashes here, i.e. 7-40 hex digits) - gitweb with XXXXX
both in bugzilla and in the redirectors.

	Jakub