* lib/m4sugar/m4sugar.m4 (_m4_defun_pro_outer)
(_m4_defun_epi_outer, _m4_require_call, m4_provide): Track name
that caused a diversion change, not just diversion number.
(m4_require): Factor...
(_m4_require_check): ...into new macro, which also checks whether
diversion that performed the expansion has been collected.
* tests/m4sugar.at (m4@&t@_require: nested): Enhance test.
Reported by Ralf Wildenhues.
Signed-off-by: Eric Blake <ebb9@byu.net>
9c4c7c5ca4