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

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

Eric Sunshine <sunshine@sunshineco.com> writes:

> What's the plan for oddball cases such as 66ae9a57b8 (t3404: rebase
> -i: demonstrate short SHA-1 collision, 2013-08-23) which depend
> implicitly upon SHA-1 without actually hardcoding any hashes? The test
> added by 66ae9a57b8, for instance, won't start failing in the face of
> NewHash, but it also won't be testing anything meaningful.
>
> Should such tests be dropped altogether? Should they be marked with a
> 'SHA1' predicate or be annotated with a comment as being
> SHA-1-specific? Something else?

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.

It's a different matter how feasible it is to attain such an ideal,
though.  t1512 was fun to write, but it was quite a lot of work to
come up with bunch of blobs, trees and commits whose object names
share the common prefix 0{10}.