Re: [PATCH v3 2/5] submodule: add gitdir path config override

> On Tue, Oct 07, 2025 at 08:41:13AM -0700, Junio C Hamano wrote: 
>> Junio C Hamano <gitster@pobox.com> writes:  
>> > Adrian Ratiu <adrian.ratiu@collabora.com> writes: 
>> > 
>> > [jc: brandon removed from CC list as the address would 
>> > bounce] 
>> > 
>> >> This adds the ability to override gitdir paths via config 
>> >> files (not .gitmodules) such that the encoding scheme (or 
>> >> plain text name if the encoding extension is disabled) can 
>> >> be changed via config entries. 
>> >> 
>> >> These entries are not added by default for all submodules: 
>> >> they should be used on an as-needed basis. 
>> >> 
>> >> A new test and a helper are added. The helper will also be 
>> >> used in further tests exercising gitdir encoding 
>> >> functionality. 
>> > 
>> > What is the use case of this?  The only reasonable use case I 
>> > can see is to set this to all the existing submodules when 
>> > you are switching the extension on before adding a new 
>> > submodule, in which case the old ones will keep using 
>> > unencoded names, while the new ones will use encoded ones. 
>>  Two things.  
>>  * I no longer mind this setting existing, but I think it 
>>  should not 
>>    be a mere "override", but the authoritative source of truth 
>>    for all submodules (see my other response on 0/5). 
> 
> I think making this the authoritative source of truth for all 
> submodules in the case where the new extension is enabled does 
> make a ton of sense.  It makes things way easier for us to 
> reason about: 
> 
>   - If the extension is set, we know to always use whatever is 
>   in the 
>     gitconfig. 
> 
>   - If any submodule path is missing we know that we are in a 
>   broken 
>     repository and can abort accordingly with directions for how 
>     to fix things. 
> 
>   - If we need to enable the extension we can trivially migrate 
>   all 
>     existing submodules by just writing their gitdir 
>     configuration. 
> 
>   - We can change the exact encoding going forward, as the 
>   extension now 
>     only indicates whether or not submodule gitdirs are tracked 
>     via the configuration or encoded "live". 
> 
> I think especially the last point is a big win, as we are not 
> stuck with the current encoding schema in case it proves 
> insufficient.