Remove reset of match_ceiling_dir_or_error in apply_environment()

[kdarkhan]

In #721, this reset was added which makes using
ThreadSafeRepository::discover_with_environment_overrides_opts inconvenient.

If the old behaviour of match_ceiling_dir_or_error = false desired, then it can be achieved by
setting it on options just before calling apply_environment().

The inverse is not true, and ThreadSafeRepository::discover_with_environment_overrides_opts
cannot enable this flag because apply_environment overrides it.

I am not sure if this change is the best approach to accomplish what I need.
Let me know if you think it is better to change discover_with_environment_overrides_opts
so that options parameter is used as override instead of default.

[Byron]

Thanks a lot for the fix of the fix :)! In hindsight I realise that hardcoding it there seems to be a mistake particularly since the value can be set by the user.

I have added a note in a separate commit that will be visible after merging, so here it is for posterity:

/// ### Note
///
/// Consider to set match_ceiling_dir_or_error = false
/// to allow discovery if an outside environment variable sets non-matching ceiling directories for greater
/// compatibility with Git.

@davidkna This change affects starship and I think the following patch can be applied right now to be safe when this trickles through with the next gix upgrade.

diff --git a/src/context.rs b/src/context.rs
index 56074469..57c6921a 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -319,7 +319,10 @@ impl<'a> Context<'a> {
                 let shared_repo =
                     match ThreadSafeRepository::discover_with_environment_overrides_opts(
                         &self.current_dir,
-                        Default::default(),
+                        gix::discover::upwards::Options {
+                            match_ceiling_dir_or_error: false,
+                            ..Default::default()
+                        },
                         git_open_opts_map,
                     ) {
                         Ok(repo) => repo,

Please do let me know if you think there were other reasons for hardcoding the value like this that aren't accounted for with this change - to me it seems sound.

[kdarkhan]

Awesome, thanks.

Reason I arrived at this issue was from starship as well since I wanted the "error" behaviour.

[Byron]

Oh, that's interesting! It seems then you will want to talk to @davidkna to see how it remains configurable instead of hardcoding the same in starship with the patch above. (But maybe I am misunderstanding something)

[kdarkhan]

Right, I will reach out to him. I am planning to add a new config option in starship if they accept.

The reason I want to have the err case is because I want to prevent starship git discover logic execute on a slower network drive. When match_ceiling_dir_or_error = true, it will accomplish the behavior I need. I can make this behavior non-default to not break other people's workflows.