Fix noproc crash during release installation

When release_handler_1:get_supervised_procs/0 does a recursive walk of
the supervision tree, it calls sys:get_status/1 on supervisors, to check
if they are suspended or running.

This fixes a race condition where a list of supervisor pids is gathered,
one of them (legitimately) exits before release_handler can examine it,
then sys:get_status/1 is called with a dead pid, causing an exit(noproc)

See: http://erlang.org/pipermail/erlang-questions/2015-August/085712.html

(To recreate this problem for testing, I added a timer:sleep into the
release_handler_1 code, and killed a supervisor during
get_supervised_procs being called).

0 files changed, 0 insertions, 0 deletions