Re: [PATCH 4/8] refs: make errno output explicit for refs_resolve_ref_unsafe

On Thu, Jun 3, 2021 at 4:51 AM Jonathan Tan [off-list ref] wrote:

quoted

This introduces refs_resolve_ref_unsafe_with_errno(), which makes the API
contract for the errno output explicit. The implementation still relies on
the global errno variable to ensure no side effects.

Looking at the next few patches, I think the plan is:

 - Introduce a new function refs_resolve_ref_unsafe_with_errno() which
   returns the error information in an out param instead of errno. Right
   now, it wraps refs_resolve_ref_unsafe().
 - Migrate all callers that require the error information to
   refs_resolve_ref_unsafe_with_errno(), and leave all callers that do
   not require the error information alone (that is, using
   refs_resolve_ref_unsafe()).
 - To ensure that all callers using refs_resolve_ref_unsafe() really do
   not use errno, set it to 0. (This is allowed by the errno contract -
   successes can set errno to whatever they want.)

If this is the plan, it should be written in the commit message.

I added more description to the commit message.

As it is, this patch handles the first and maybe part of the second
step, and patch 5 handles the rest of the second step? I think the
patches should be more clearly divided.

Done.

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