Fix error handling in GetTreeEntries
As noted by @pks-t in !4400 (closed), ResolveRevision
does not ever return a catfile.ErrNotFound
. Instead, it
returns a git.ReferenceNotFound
This is a reroll of !4400 (closed)
Rails pipeline MR gitlab!82957 (closed)
Edited by Hordur Freyr Yngvason