pass host and port to a "ListenSocket" in IO::Socket::Async

pass-host-and-port-on-listen.patch

diff --git a/src/core/IO/Socket/Async.pm6 b/src/core/IO/Socket/Async.pm6
index 87dcf39a5..a86a9f08f 100644
--- a/src/core/IO/Socket/Async.pm6
+++ b/src/core/IO/Socket/Async.pm6
@@ -195,23 +195,32 @@ my class IO::Socket::Async {
         $p
     }
 
+    class ListenSocket is Supply {
+        has Promise $.socket-host;
+        has Promise $.socket-port;
+    }
+
     my class SocketListenerTappable does Tappable {
         has $!host;
         has $!port;
         has $!backlog;
         has $!encoding;
         has $!scheduler;
+        has $!socket-host;
+        has $!socket-port;
 
-        method new(:$host!, :$port!, :$backlog!, :$encoding!, :$scheduler!) {
-            self.CREATE!SET-SELF($host, $port, $backlog, $encoding, $scheduler)
+        method new(:$host!, :$port!, :$backlog!, :$encoding!, :$scheduler!, :$socket-host!, :$socket-port!) {
+            self.CREATE!SET-SELF($host, $port, $backlog, $encoding, $scheduler, $socket-host, $socket-port)
         }
 
-        method !SET-SELF($!host, $!port, $!backlog, $!encoding, $!scheduler) { self }
+        method !SET-SELF($!host, $!port, $!backlog, $!encoding, $!scheduler, $!socket-host, $!socket-port) { self }
 
         method tap(&emit, &done, &quit, &tap) {
             my $lock := Lock::Async.new;
             my $tap;
             my int $finished = 0;
+            my $host-vow = $!socket-host.vow;
+            my $port-vow = $!socket-port.vow;
             $lock.protect: {
                 my $cancellation := nqp::asynclisten(
                     $!scheduler.queue(:hint-affinity),
@@ -222,10 +231,13 @@ my class IO::Socket::Async {
                                 # do nothing
                             }
                             elsif err {
-                                quit(X::AdHoc.new(payload => err));
+                                my $exc = X::AdHoc.new(payload => err);
+                                quit($exc);
+                                $host-vow.break($exc) unless $host-vow.promise;
+                                $port-vow.break($exc) unless $port-vow.promise;
                                 $finished = 1;
                             }
-                            else {
+                            elsif socket {
                                 my $client_socket := nqp::create(IO::Socket::Async);
                                 nqp::bindattr($client_socket, IO::Socket::Async,
                                     '$!VMIO', socket);
@@ -244,6 +256,10 @@ my class IO::Socket::Async {
                                 setup-close($client_socket);
                                 emit($client_socket);
                             }
+                            elsif socket-host {
+                                $host-vow.keep(~socket-host);
+                                $port-vow.keep(+socket-port);
+                            }
                         }
                     },
                     $!host, $!port, $!backlog, SocketCancellation);
@@ -272,8 +288,10 @@ my class IO::Socket::Async {
     method listen(IO::Socket::Async:U: Str() $host, Int() $port, Int() $backlog = 128,
                   :$enc = 'utf-8', :$scheduler = $*SCHEDULER) {
         my $encoding = Encoding::Registry.find($enc);
-        Supply.new: SocketListenerTappable.new:
-            :$host, :$port, :$backlog, :$encoding, :$scheduler
+        my Promise $socket-host .= new;
+        my Promise $socket-port .= new;
+        ListenSocket.new: :$socket-host, :$socket-port SocketListenerTappable.new:
+            :$host, :$port, :$backlog, :$encoding, :$scheduler, :$socket-host, :$socket-port
     }
 
     sub setup-close(\socket --> Nil) {