signal.c: get rid of deadlock by discarded signals

* signal.c (rb_f_kill): get rid of deadlock as unhandled and
  discarded signals do not make interrupt_cond signaled.
  based on the patch by Kazuki Tsujimoto at [ruby-dev:48606].
  [Bug #9820]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47832 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 1 deletions

diff --git a/signal.c b/signal.c
index 171f5ac971..c42ce0aee0 100644
--- a/signal.c
+++ b/signal.c
@@ -487,7 +487,8 @@ rb_f_kill(int argc, const VALUE *argv)
 		  default:
 		    t = signal_ignored(sig);
 		    if (t) {
-			if (t < 0) ruby_kill(pid, sig);
+			if (t < 0 && kill(pid, sig))
+			    rb_sys_fail(0);
 			break;
 		    }
 		    signal_enque(sig);