Re: [PATCH] abbrev: allow extending beyond 20 chars to disambiguate

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 11, 2025, 21:25 UTC
Message-ID: <xmqq4iud1rfm.fsf@gitster.g>
In-Reply-To: <aJpd2MYMWgEoxQWi@fruit.crustytoothpaste.net>

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

Show 7 quoted lines

> On 2025-08-11 at 15:26:32, Junio C Hamano wrote:
>> When you have two or more objects with object names that share more
>> than half the length of the hash algorithm in use (e.g. 10 bytes for
>> SHA-1 that produces 20-byte/160-bit hash), find_unique_abbrev()
>> fails to show disambiguation.
>
> Is this really the case?

What I wrote in the above is correct.

> If the restriction is due to using
> GIT_MAX_RAWSZ instead of GIT_MAX_HEXSZ, then that's 32 vs. 64 in our
> modern codebase.

The above numbers are correct but irrelevant ;-).

The thing is, the offending commit changed from 40-bytes (GIT_SHA1_HEXSZ) to 32-bytes (GIT_MAX_RAWSZ). Plase see v2 patch.

Thanks.