* lisp/vc/vc-git.el
(vc-git--with-apply-temp-to-staging): Rename ...
(vc-git--with-apply-temp): ... to this. New ARGS parameter.
All uses changes.
(vc-git--checkin): In POST function, apply PATCH-STRING to the
working tree with 'git apply --3way --ours'.
* lisp/vc/vc-hg.el (vc-hg--checkin): Document what the call to
'hg update' is for.
* test/lisp/vc/vc-tests/vc-tests.el (vc-test--checkin-patch):
Delete completed FIXME and workaround.