Merge branch 'mh/blame-worktree'

"git blame file" allowed the lineage of lines in the uncommitted, unadded contents of "file" to be inspected, but it refused when "file" did not appear in the current commit. When "file" was created by renaming an existing file (but the change has not been committed), this restriction was unnecessarily tight. * mh/blame-worktree: t/t8003-blame-corner-cases.sh: Use here documents blame: allow to blame paths freshly added to the index