If the first argument of sigaction() was a string, not a number

(or a SIGXXX 'constant') one got first (if using -w) 'Argument "FOO"
isn't numeric in subroutine entry ...' but after that one got
(depending on the OS) either a coredump (because of trying to
assign to *0 in mg_get) or a hang (because of the sigprocmask()
blocking signals inside POSIX::sigaction, a nasty hang since
one obviously cannot interrupt it...only SIGKILL works).
In older Perls (tried with 5.6.1) one got 'No such signal: SIGZERO ...'
because of the string becoming zero due to the XS typemap magic.
Resolved by making the POSIX::sigaction to try harder to figure
out a valid signal number (one still gets the warning, though),
and returning undef if no sense can be made.

p4raw-id: //depot/perl@19809

1 files changed, 23 insertions, 1 deletions

diff --git a/ext/POSIX/t/sigaction.t b/ext/POSIX/t/sigaction.t
index 63ff17dae3..d2db20b0ff 100644
--- a/ext/POSIX/t/sigaction.t
+++ b/ext/POSIX/t/sigaction.t
@@ -21,7 +21,7 @@ use vars qw/$bad7 $ok10 $bad18 $ok/;
 
 $^W=1;
 
-print "1..18\n";
+print "1..21\n";
 
 sub IGNORE {
 	$bad7=1;
@@ -133,3 +133,25 @@ if ($^O eq 'VMS') {
     print $bad18 ? "not ok 18\n" : "ok 18\n";
 }
 
+{
+    local $SIG{__WARN__} = sub { }; # Just suffer silently.
+
+    my $hup20;
+    my $hup21;
+
+    sub hup20 { $hup20++ }
+    sub hup21 { $hup21++ }
+
+    sigaction("FOOBAR", $newaction);
+    print "ok 19\n"; # no coredump, still alive
+
+    $newaction = POSIX::SigAction->new("hup20");
+    sigaction("SIGHUP", $newaction);
+    kill "HUP", $$;
+    print $hup20 == 1 ? "ok 20\n" : "not ok 20\n";
+
+    $newaction = POSIX::SigAction->new("hup21");
+    sigaction("HUP", $newaction);
+    kill "HUP", $$;
+    print $hup21 == 1 ? "ok 21\n" : "not ok 21\n";
+}