Reproduction steps

1. Clone a repository and create a separate worktree for it (using git worktree).
2. Start bisect on the worktree
3. Retireve all refs for the worktree using git_reference_foreach

Expected behavior

git_reference_foreach returns the bisec/good and bisec/bad refs.

Actual behavior

git_reference_foreach does not return the bisec/good and bisec/bad refs.
Those refs are only returned in the main repo when bisecting is started there.

The refs bisect/good and bisec/bad are stored in .git/worktree/NAME/refs/bisect/....

Version of libgit2 (release number or SHA1)

918a7d1, still in 1.5.0

Operating system(s) tested

Win10 1909, x64