testing/fulltests/support/myip: Fix a runtime error

Fix the runtime error "Constant subroutine main::AF_INET6 redefined"
by using 'require' (evaluated at run-time) instead of 'use' (evaluated
at compile-time).

Author: bvanassche

testing/fulltests/support/myip

@@ -8,15 +8,22 @@
 
 use strict;
 use warnings;
-import IO::Socket::INET6;
+
 # For older Perl versions AF_INET6 is defined in the Socket6 package. For newer
 # Perl versions all IPv6 functionality we need is defined in the Socket package.
-if (eval "use Socket6 qw(AF_INET6 inet_ntop inet_pton pack_sockaddr_in6
-                             sockaddr_in6)") {
-    use Socket qw(AF_INET SOCK_DGRAM pack_sockaddr_in sockaddr_in);
-} else {
-    use Socket qw(AF_INET AF_INET6 SOCK_DGRAM inet_ntop inet_pton
-		  pack_sockaddr_in pack_sockaddr_in6 sockaddr_in sockaddr_in6);
+BEGIN {
+    # Try to load Socket6
+    if (eval "require Socket6; Socket6->import(qw(AF_INET6 inet_ntop inet_pton pack_sockaddr_in6 sockaddr_in6)); 1") {
+        # If loading Socket6 succeeded, only load the v4 parts from Socket.
+        require Socket;
+        Socket->import(qw(AF_INET SOCK_DGRAM pack_sockaddr_in sockaddr_in));
+    } else {
+        # If loading Socket6 failed, assume a modern Perl where Socket has
+	# everything.
+        require Socket;
+        Socket->import(qw(AF_INET AF_INET6 SOCK_DGRAM inet_ntop inet_pton
+                          pack_sockaddr_in pack_sockaddr_in6 sockaddr_in sockaddr_in6));
+    }
 }
 
 
@@ -39,7 +46,7 @@ if ($v6) {
     socket(my $sock2, $af, SOCK_DGRAM, 0);
     my $i = 1;
     while (1) {
-	bind($sock2, sockaddr_in6(0, $ip6_address, $i)) && last;
+	bind($sock2, sockaddr_in6($i, $ip6_address)) && last;
 	$i++;
     }
     $myip = inet_ntop($af, $ip6_address);