Allow AF_UNIX pathnames up to the maximum 108 bytes on Linux,
since it does not require sun_path to be null terminated.

diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -1187,27 +1187,16 @@ getsockaddrarg(PySocketSockObject *s, Py
 
 		addr = (struct sockaddr_un*)addr_ret;
 #ifdef linux
-		if (len > 0 && path[0] == 0) {
-			/* Linux abstract namespace extension */
-			if (len > sizeof addr->sun_path) {
-				PyErr_SetString(socket_error,
-						"AF_UNIX path too long");
-				return 0;
-			}
-		}
-		else
-#endif /* linux */
-                {
-			/* regular NULL-terminated string */
-			if (len >= sizeof addr->sun_path) {
-				PyErr_SetString(socket_error,
-						"AF_UNIX path too long");
-				return 0;
-			}
-			addr->sun_path[len] = 0;
+		if (len > sizeof(addr->sun_path)) {
+#else
+		if (len >= sizeof(addr->sun_path)) {
+#endif
+			PyErr_SetString(socket_error, "AF_UNIX path too long");
+			return 0;
 		}
 		addr->sun_family = s->sock_family;
 		memcpy(addr->sun_path, path, len);
+		memset(addr->sun_path + len, 0, sizeof(addr->sun_path) - len);
 #if defined(PYOS_OS2)
 		*len_ret = sizeof(*addr);
 #else