Fix build with newer glib

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

0001-src-avoid-warnings-from-use-of-G_GNUC_FALLTHROUGH.patch

@@ -0,0 +1,72 @@
+From 2e6adf9b85cee3b85a9f7da8d976f3dd022afaa3 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= <berrange@redhat.com>
+Date: Tue, 27 Jul 2021 16:25:12 +0100
+Subject: [PATCH] src: avoid warnings from use of G_GNUC_FALLTHROUGH
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Since glib >= 2.69 we get warnings:
+
+../src/ovirt-foreign-menu.c: In function 'ovirt_foreign_menu_next_async_step':
+../src/ovirt-foreign-menu.c:319:13: error: Not available before 2.60 [-Werror]
+  319 |         G_GNUC_FALLTHROUGH;
+      |             ^~~~~~~~~~~~~~~
+../src/ovirt-foreign-menu.c:345:13: error: Not available before 2.60 [-Werror]
+  345 |         G_GNUC_FALLTHROUGH;
+      |             ^~~~~~~~~~~~~~~
+../src/ovirt-foreign-menu.c:351:13: error: Not available before 2.60 [-Werror]
+  351 |         G_GNUC_FALLTHROUGH;
+      |             ^~~~~~~~~~~~~~~
+../src/ovirt-foreign-menu.c:357:13: error: Not available before 2.60 [-Werror]
+  357 |         G_GNUC_FALLTHROUGH;
+      |             ^~~~~~~~~~~~~~~
+cc1: all warnings being treated as errors
+
+GLib is right to warn about this, since it does not know that we
+provided our own back-compat definition of the macro. For now we have to
+temporarily purge glib's macro entirely in order to get rid of the
+warning that is bogus for our usage.
+
+Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
+---
+ src/ovirt-foreign-menu.c | 23 +++++++++++++++++------
+ 1 file changed, 17 insertions(+), 6 deletions(-)
+
+diff --git a/src/ovirt-foreign-menu.c b/src/ovirt-foreign-menu.c
+index c19e913..91b6824 100644
+--- a/src/ovirt-foreign-menu.c
++++ b/src/ovirt-foreign-menu.c
+@@ -31,12 +31,23 @@
+ #include "virt-viewer-util.h"
+ #include "glib-compat.h"
+ 
+-#if !GLIB_CHECK_VERSION(2, 60, 0)
+-# if __GNUC_PREREQ (7, 0)
+-#  define G_GNUC_FALLTHROUGH __attribute__((fallthrough))
+-# else
+-#  define G_GNUC_FALLTHROUGH do {} while(0)
+-# endif
++/* GLib 2.69 annotated macros with version tags, and
++ * since we set GLIB_VERSION_MAX_ALLOWED  to 2.48
++ * it complains if we use G_GNUC_FALLTHROUGH at
++ * all. We temporarily purge the GLib definition
++ * of G_GNUC_FALLTHROUGH and define it ourselves.
++ * When we set min glib >= 2.60, we can delete
++ * all this
++ */
++#ifndef __GNUC_PREREQ
++# define __GNUC_PREREQ(maj, min) \
++    ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
++#endif
++#undef G_GNUC_FALLTHROUGH
++#if __GNUC_PREREQ (7, 0)
++# define G_GNUC_FALLTHROUGH __attribute__((fallthrough))
++#else
++# define G_GNUC_FALLTHROUGH do {} while(0)
+ #endif
+ 
+ typedef enum {
+-- 
+2.31.1
+

virt-viewer.spec

@@ -10,11 +10,12 @@
 
 Name: virt-viewer
 Version: 10.0
-Release: 3%{?dist}
+Release: 4%{?dist}
 Summary: Virtual Machine Viewer
 License: GPLv2+
 URL: https://gitlab.com/virt-viewer/virt-viewer
 Source0: https://virt-manager.org/download/sources/%{name}/%{name}-%{version}.tar.xz
+Patch1: 0001-src-avoid-warnings-from-use-of-G_GNUC_FALLTHROUGH.patch
 Requires: openssh-clients
 
 BuildRequires: gcc
@@ -45,7 +46,7 @@ to virtual machines. It uses the GTK-VNC or SPICE-GTK widgets to provide
 the display, and libvirt for looking up VNC/SPICE server details.
 
 %prep
-%setup -q
+%autosetup -p1
 
 %build
 %if !%{with_govirt}
@@ -77,6 +78,9 @@ the display, and libvirt for looking up VNC/SPICE server details.
 %{_datadir}/bash-completion/completions/virt-viewer
 
 %changelog
+* Wed Aug 11 2021 Daniel P. Berrangé <berrange@redhat.com> - 10.0-4
+- Fix build with newer glib (rhbz#1988037)
+
 * Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 10.0-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild