Re: [PATCH v3 4/5] submodule: encode gitdir paths to avoid conflicts

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 7, 2025, 17:20 UTC
Message-ID: <xmqqo6qik4r9.fsf@gitster.g>
In-Reply-To: <87cy6y4xb4.fsf@collabora.com>

Adrian Ratiu <adrian.ratiu@collabora.com> writes:

> I will percent encode the upper case by modifying 
> is_rfc3986_unreserved().

Again, do we really need to encode everything? We need to only when (1) there are other submodules that would collide with us (e.g., by being only case-different, or by having our name plus a slash as the prefix of their name, make us overlap with them) or (2) our name is not filesystem friendly and needs munging. A letter being in an upper case is not a crime.

Show 13 quoted lines

>>> For now url-encoding is the only option, however in the future 
>>> we may add alternatives (other encodings, hashes or even 
>>> hash_name). 
>> 
>> Let's not say "For now". 
>> 
>> Choose a single encoding that we can use forever so that we do 
>> not have to upgrade extensions.encodeSubmoduleName with suffixes 
>> like extensions.encodeSubmoduleNamev2, 
>> extensions.encodeSubmoduleNamev3, etc. to cover our earlier 
>> mistakes and force renaming on users. 
>
> Understood. Will drop that idea.

If we are to consistently use submodule.<name>.gitdirpath as the authoritative collection of name-path mapping, then the exact algorithm to derive path from name can be improved over time without having to worry about an old submodule whose path was computed by older iteration of the algorithm colliding with a new submodule whose path is derived by the more modern algorithm. So I do not mind to make ourselves aware of the possibility that we can tweak and improve. But as I said elsewhere, I do not think we need to even say what exactly algorithm is used to the end-users.

Thanks.