On Sat, 08 Nov 2025, Aaron Schrab [off-list ref] wrote:

At 17:05 +0200 07 Nov 2025, Adrian Ratiu 
[off-list ref] wrote: 

quoted

Add a new check in validate_submodule_git_dir() to detect and 
prevent case-folding filesystem colisions. When this new check 
is triggered, a stricter casefolding aware URI encoding is used 
to percent-encode uppercase characters, e.g. Foo becomes %46oo. 
By using this check/retry mechanism the uppercase encoding is 
only applied when necessary, so case-sensitive filesystems are 
not affected. 

What happens if `Foo` is added first and doesn't conflict with 
anything,  then later a new submodule is added which would 
naturally get the name  `foo` which would conflict and doesn't 
have any upper case characters to  encode to avoid the conflict? 

What an excellent question. Thank you!

Right now, in v4, in this case the user adding the second `foo` 
module will have to manually set the submodule.foo.gitdir config 
to avoid the conflict, because Foo already uses the coliding path.

I can add a test specifically for this edge case to exercise 
config overrides on case-folding file-systems conflicts.

OR...

Maybe we could derive a new path automatically (eg foo2 or foo_, 
suggestions welcome) and use it if valid. This way, there is no 
user intervention.

Do you have any preference?

Thanks again,
Adrian