elpa - problem with stashes inside worktree

[Filipp Gunbin <fgunbin@fastmail.fm>]

Hi, I've got this problem in elpa repo:

- make a new stash in some package (just "git stash")
- C-x v d on top-level elpa directory
- vc-git-stash-apply-at-point on the just created stash fails

Stash diff looks like this:

--8<---------------cut here---------------start------------->8---
diff --git a/javaimp.el b/javaimp.el
index 8e27452418..a9781630e9 100644
--- a/javaimp.el
+++ b/javaimp.el
@@ -577,4 +577,6 @@ cache."
 
 (provide 'javaimp)
 
+asdf
+
 ;;; javaimp.el ends here
--8<---------------cut here---------------end--------------->8---

The file path is wrong, and change is applied to the wrong file.  Looks
like Git creates stash using package worktree dir as the top directory.

From C-x v d on a package directory, stash can be applied normally.

Maybe we could extend vc-dir to specially treat this case?  I doubt that
Git worktrees are intended to be used this way (inside the main tree)…

Filipp