[gnome-control-center] build: Require udev for Wayland support

[Bastien Nocera <hadess src gnome org>]

commit a43d59dc86d507945f92816deb18117a417114b4
Author: Bastien Nocera <hadess hadess net>
Date:   Thu Apr 9 12:53:06 2015 +0200

    build: Require udev for Wayland support
    
    If GTK+ was built with Wayland support, we'll enable the udev
    "GsdDeviceManager". But that needs udev to be available.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747548

 configure.ac |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8ebadfc..cd59931 100644
--- a/configure.ac
+++ b/configure.ac
@@ -184,6 +184,13 @@ if test "x$have_udev" = xyes ; then
 fi
 AM_CONDITIONAL(HAVE_UDEV, [test "x$have_udev" = "xyes"])
 
+PKG_CHECK_MODULES(WAYLAND, gdk-wayland-3.0, have_wayland=yes, have_wayland=no)
+if test "x$have_wayland" = xyes ; then
+       if test "x$have_udev" != xyes ; then
+               AC_MSG_ERROR([udev is required for Wayland support])
+       fi
+fi
+
 PKG_CHECK_MODULES(NETWORK_MANAGER, NetworkManager >= $NETWORK_MANAGER_REQUIRED_VERSION
                   libnm-glib >= $NETWORK_MANAGER_REQUIRED_VERSION
                   libnm-glib-vpn >= $NETWORK_MANAGER_REQUIRED_VERSION