From 85f3bc133f258a436fb8018580dd23acf5220a0c Mon Sep 17 00:00:00 2001
From: Philip Withnall <withnall@endlessm.com>
Date: Tue, 27 Feb 2018 12:48:05 +0000
Subject: [PATCH] gnetworkmonitornetlink: Fix potential GMainContext issue

Previously, the GSource would be attached to whatever GMainContext was
the thread default at the time; but that might no longer be the same as
the default at the time of constructing the GNetworkMonitor.

Save the default from construction time, so that source callbacks are
always invoked in the same GMainContext.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://bugzilla.gnome.org/show_bug.cgi?id=793880
---
 gio/gnetworkmonitornetlink.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/gio/gnetworkmonitornetlink.c b/gio/gnetworkmonitornetlink.c
index 942440b5c..d7d9cb79a 100644
--- a/gio/gnetworkmonitornetlink.c
+++ b/gio/gnetworkmonitornetlink.c
@@ -46,6 +46,7 @@ struct _GNetworkMonitorNetlinkPrivate
 {
   GSocket *sock;
   GSource *source, *dump_source;
+  GMainContext *context;
 
   GPtrArray *dump_networks;
 };
@@ -75,7 +76,6 @@ g_network_monitor_netlink_init (GNetworkMonitorNetlink *nl)
   nl->priv = g_network_monitor_netlink_get_instance_private (nl);
 }
 
-
 static gboolean
 g_network_monitor_netlink_initable_init (GInitable     *initable,
                                          GCancellable  *cancellable,
@@ -143,11 +143,11 @@ g_network_monitor_netlink_initable_init (GInitable     *initable,
     }
 
   g_socket_set_blocking (nl->priv->sock, FALSE);
+  nl->priv->context = g_main_context_ref_thread_default ();
   nl->priv->source = g_socket_create_source (nl->priv->sock, G_IO_IN, NULL);
   g_source_set_callback (nl->priv->source,
                          (GSourceFunc) read_netlink_messages, nl, NULL);
-  g_source_attach (nl->priv->source,
-                   g_main_context_get_thread_default ());
+  g_source_attach (nl->priv->source, nl->priv->context);
 
   return TRUE;
 }
@@ -209,8 +209,7 @@ queue_request_dump (GNetworkMonitorNetlink *nl)
   nl->priv->dump_source = g_timeout_source_new (1000);
   g_source_set_callback (nl->priv->dump_source,
                          (GSourceFunc) timeout_request_dump, nl, NULL);
-  g_source_attach (nl->priv->dump_source,
-                   g_main_context_get_thread_default ());
+  g_source_attach (nl->priv->dump_source, nl->priv->context);
 }
 
 static void
@@ -457,6 +456,8 @@ g_network_monitor_netlink_finalize (GObject *object)
       g_source_unref (nl->priv->dump_source);
     }
 
+  g_clear_pointer (&nl->priv->context, g_main_context_unref);
+
   G_OBJECT_CLASS (g_network_monitor_netlink_parent_class)->finalize (object);
 }
 
@@ -465,7 +466,7 @@ g_network_monitor_netlink_class_init (GNetworkMonitorNetlinkClass *nl_class)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (nl_class);
 
-  gobject_class->finalize  = g_network_monitor_netlink_finalize;
+  gobject_class->finalize = g_network_monitor_netlink_finalize;
 }
 
 static void