tests: avoid zombie lockup with test-hup The 'while kill -0' recipe can cause a livelock if the process we're waiting to die is a normal child process. If it becomes a zombie that the shell doesn't reap (shell bug?), it will continue to be able to accept signals. So instead, we just wait(1).

--- a/tests/test-hup.t	Mon Apr 02 16:04:07 2012 -0500
+++ b/tests/test-hup.t	Mon Apr 02 16:46:58 2012 -0500
@@ -15,7 +15,7 @@
   > kill -HUP $P
   > ) > p
 
-  $ while kill -0 $P 2>/dev/null; do true; done
+  $ wait
   $ cat out
   0
   0