Another attempt at fixing gcc 8 build

0001-m4-disable-Wcast-function-type.patch

@@ -0,0 +1,37 @@
+From 9777492dde8ad40882b804fcda332cb3e1f46271 Mon Sep 17 00:00:00 2001
+From: Lubomir Rintel <lkundrak@v3.sk>
+Date: Wed, 7 Feb 2018 11:23:08 +0100
+Subject: [PATCH] m4: disable -Wcast-function-type
+
+This fixes the GCC 8 build. It disables the warning conditionally so that we
+get the warning back if glib gets fixed.
+
+(cherry picked from commit 631982a796a0eeb412551c61469a1cfb83e3f438)
+---
+ m4/compiler_options.m4 | 10 ++++++++++
+ 1 file changed, 10 insertions(+)
+
+diff --git a/m4/compiler_options.m4 b/m4/compiler_options.m4
+index ccb51f5e6..2350571e2 100644
+--- a/m4/compiler_options.m4
++++ b/m4/compiler_options.m4
+@@ -127,6 +127,16 @@ if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
+ 		[union { int a[1]; int b[2]; } c = { 0 }]
+ 	)
+ 
++	dnl a new warning in gcc 8, glib 2.55 doesn't play nice yet
++	NM_COMPILER_WARNING([cast-function-type],
++		[#include <glib-object.h>]
++		[typedef struct { GObject parent; } NMObject;]
++		[typedef struct { GObjectClass parent; } NMObjectClass;]
++		[static void nm_object_init (NMObject *object) { } ]
++		[static void nm_object_class_init (NMObjectClass *object) { }]
++		[G_DEFINE_TYPE (NMObject, nm_object, G_TYPE_OBJECT)]
++	)
++
+ 	CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS"
+ else
+ 	AC_MSG_RESULT(no)
+-- 
+2.14.3
+

NetworkManager.spec

@@ -93,6 +93,7 @@ Source3: 20-connectivity-fedora.conf
 #Patch1: 0001-some.patch
 Patch1: 0001-build-fix-configure-check-for-CC-support-of-_Generic.patch
 Patch2: 0002-ovs-fix-compiler-error-for-passing-NMDevice-pointer-.patch
+Patch3: 0001-m4-disable-Wcast-function-type.patch
 
 Requires(post): systemd
 Requires(preun): systemd
@@ -363,6 +364,7 @@ by nm-connection-editor and nm-applet in a non-graphical environment.
 #%patch1 -p1
 %patch1 -p1
 %patch2 -p1
+%patch3 -p1
 
 %build
 %if %{with regen_docs}