Re: [PATCH 00/10] Hash-independent tests (part 1)

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

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

>> Ideally, the existing one be annotated with prereq SHA1, and also
>> duplicated with a tweak to cause the same kind of (half-)collision
>> under the NewHash and be annotated with prereq NewHash.
>
> That's a good idea. I wonder whether we want to be a bit more specific,
> though, so that we have something grep'able for the future? Something like
> SHA1_SHORT_COLLISION or some such?

Sorry, you lost me.  

What I meant was that a test, for example, that expects the object
name for an empty blob begins with e69de29 is valid ONLY when Git is
using SHA-1 to name objects, so such a test should be run only when
Git is using SHA-1 and no other hash.  All tests in t1512 that
expects the sequence of events in it would yield blobs and trees
whose names have many leading "0"s are the same way.

I think it would do to have a single prerequisite to cover all such
tests: "Run this piece of test only when Git is using SHA-1 hash".
I do not think you need a set of prerequisites to say "Run this with
SHA-1 because we are testing X" where X may be "disambiguation",
"unique-abbrev", "loose-refs", or whatever.