fixed ValueError for AF_INET6 sockets (#2431)

* fixed ValueError for AF_INET6 sockets

* changelog entry added for #2431

* Update 2431.bugfix

* rename has_ipv6 to HAS_IPV6: it's a contant

CHANGES/2431.bugfix

@@ -0,0 +1 @@
+fixed ValueError for AF_INET6 sockets if a preexisting INET6 socket to the `aiohttp.web.run_app` function.

aiohttp/web.py

@@ -421,7 +421,7 @@ def _make_server_creators(handler, *, loop, ssl_context,
         if hasattr(socket, 'AF_UNIX') and sock.family == socket.AF_UNIX:
             uris.append('{}://unix:{}:'.format(scheme, sock.getsockname()))
         else:
-            host, port = sock.getsockname()
+            host, port = sock.getsockname()[:2]
             uris.append(str(base_url.with_host(host).with_port(port)))
     return server_creations, uris
 

tests/test_run_app.py

@@ -42,6 +42,16 @@
 )
 del _has_unix_domain_socks, _abstract_path_failed
 
+HAS_IPV6 = socket.has_ipv6
+if HAS_IPV6:
+    # The socket.has_ipv6 flag may be True if Python was built with IPv6
+    # support, but the target system still may not have it.
+    # So let's ensure that we really have IPv6 support.
+    try:
+        socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
+    except OSError:
+        HAS_IPV6 = False
+
 
 # tokio event loop does not allow to override attributes
 def skip_if_no_dict(loop):
@@ -451,6 +461,31 @@ def test_run_app_preexisting_inet_socket(loop, mocker):
         assert "http://0.0.0.0:{}".format(port) in printer.call_args[0][0]
 
 
+@pytest.mark.skipif(not HAS_IPV6, reason="IPv6 is not available")
+def test_run_app_preexisting_inet6_socket(loop, mocker):
+    skip_if_no_dict(loop)
+
+    mocker.spy(loop, 'create_server')
+
+    app = web.Application()
+    mocker.spy(app, 'startup')
+
+    sock = socket.socket(socket.AF_INET6)
+    with contextlib.closing(sock):
+        sock.bind(('::', 0))
+        port = sock.getsockname()[1]
+
+        printer = mock.Mock(wraps=stopper(loop))
+        web.run_app(app, loop=loop, sock=sock, print=printer)
+
+        assert not loop.is_closed()
+        loop.create_server.assert_called_with(
+            mock.ANY, sock=sock, backlog=128, ssl=None
+        )
+        app.startup.assert_called_once_with()
+        assert "http://:::{}".format(port) in printer.call_args[0][0]
+
+
 @skip_if_no_unix_socks
 def test_run_app_preexisting_unix_socket(loop, mocker):
     skip_if_no_dict(loop)