tree ddfe1a8b7b1b95f19224d5a3c9e64bf2b7504c84
parent ae5838f118a4819e608990a815bf8fc482be5772
author David Turner <dturner@twosigma.com> 1480651601 -0500
committer David Turner <dturner@twosigma.com> 1480651917 -0500

git_rebase_init: correctly handle detached HEAD

git_rebase_finish relies on head_detached being set, but
rebase_init_merge was only setting it when branch->ref_name was unset.
But branch->ref_name would be set to "HEAD" in the case of detached
HEAD being either implicitly (NULL) or explicitly passed to
git_rebase_init.