Re: [PATCH v2] refs: remove lookup cache for reference-transaction hook

[Jeff King <peff@peff.net>]

On Tue, Aug 25, 2020 at 11:09:54AM -0700, Junio C Hamano wrote:

> >> +test_perf "nonatomic push" '
> >> +	git push ./target-repo.git $(test_seq 1000) &&
> >> +	git push --delete ./target-repo.git $(test_seq 1000)
> >>  '
> >
> > This works as far as Git is concerned, but "seq 1000" output with NULs
> > is 3893 bytes. I wonder if some platforms might run into command-line
> > limits there.
> 
> That was my thought when I saw the above as well.  In addition, I do
> not think it is a good idea to encourage digit-only refnames.

Good point. It gets hairy at four digits:

  $ git show 1000
  error: short SHA1 1000 is ambiguous
  hint: The candidates are:
  hint:   10000434d2 tree
  hint:   10007bcb9e tree
  hint:   10008a0e22 tree
  hint:   1000bdf512 tree
  hint:   1000dc2368 blob
  fatal: ambiguous argument '1000': unknown revision or path not in the working tree.

So I think if the test works it may be relying on the exact object ids
that happen to be generated (which fortunately are at least
deterministic these days, but it may be a trap waiting to spring for
somebody later).

-Peff