push: fix subtle bug in prepush logic
A test case demonstrating the bug has been added.
Contributed by Henrik Stuart and Sune Foldager.
inserv1
% inserve
adding a
adding b
adding c
adding d
adding e
adding f
adding hg.pid
M c
A g
A h
R a
R e
! b
Are we able to kill the service? if not, the service died on some error