Fix for ID 20000915.011, IO::Select warning for an undefined fd.

p4raw-id: //depot/perl@7384

diff --git a/ext/IO/lib/IO/Select.pm b/ext/IO/lib/IO/Select.pm
index e84b54f..1a3a26f 100644 (file)
--- a/ext/IO/lib/IO/Select.pm
+++ b/ext/IO/lib/IO/Select.pm
@@ -56,6 +56,7 @@ sub exists
 sub _fileno
 {
  my($self, $f) = @_;
+ return unless defined $f;
  $f = $f->[0] if ref($f) eq 'ARRAY';
  ($f =~ /^\d+$/) ? $f : fileno($f);
 }