[gnome-settings-daemon/benzea/fix-mpris-disconnect] Fix MPRIS issues with disconnecting clients

[Benjamin Berg <bberg src gnome org>]

commit 19633583b6d56e8aceaee4900e1afd303629ac70
Author: Benjamin Berg <bberg redhat com>
Date:   Mon Dec 10 18:42:38 2018 +0100

    Fix MPRIS issues with disconnecting clients
    
    When clients disconnected and they were not the active client they would
    not be removed from the list. This caused the controller to create a
    proxy for non-existing clients, causing a bad state. The "connecting"
    boolean was also not reset, meaning that a new MPRIS client would never
    be used.
    
    Fix this by removing clients from the list of names when they disappear.
    Also handle the corner case that the proxy creation fails by resetting
    the "connecting" flag and trying to connect to the next known name.
    
    Fixes #45

 plugins/media-keys/mpris-controller.c | 65 ++++++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 20 deletions(-)
---
diff --git a/plugins/media-keys/mpris-controller.c b/plugins/media-keys/mpris-controller.c
index f2baef2d..fff96cb4 100644
--- a/plugins/media-keys/mpris-controller.c
+++ b/plugins/media-keys/mpris-controller.c
@@ -39,6 +39,7 @@ struct _MprisControllerPrivate
   gboolean connecting;
 };
 
+static void mpris_player_try_connect (MprisController *self);
 
 static void
 mpris_controller_dispose (GObject *object)
@@ -115,7 +116,14 @@ mpris_proxy_ready_cb (GObject      *object,
   if (!proxy)
     {
       if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
-        g_warning ("Error connecting to mpris interface %s", error->message);
+        {
+          g_warning ("Error connecting to mpris interface %s", error->message);
+
+          priv = MPRIS_CONTROLLER (user_data)->priv;
+          priv->connecting = FALSE;
+
+          mpris_player_try_connect (MPRIS_CONTROLLER (user_data));
+        }
       g_clear_error (&error);
       return;
     }
@@ -145,6 +153,30 @@ start_mpris_proxy (MprisController *self, const gchar *name)
   priv->connecting = TRUE;
 }
 
+static void
+mpris_player_try_connect (MprisController *self)
+{
+  MprisControllerPrivate *priv = self->priv;
+
+  GSList *first;
+  gchar *name;
+
+  if (priv->connecting || priv->mpris_client_proxy)
+    return;
+
+  if (!priv->other_players)
+    return;
+
+  first = priv->other_players;
+  name = first->data;
+
+  start_mpris_proxy (self, name);
+
+  priv->other_players = priv->other_players->next;
+  g_free (name);
+  g_slist_free_1 (first);
+}
+
 static void
 mpris_player_appeared (GDBusConnection *connection,
                        const gchar     *name,
@@ -154,10 +186,8 @@ mpris_player_appeared (GDBusConnection *connection,
   MprisController *self = user_data;
   MprisControllerPrivate *priv = MPRIS_CONTROLLER (self)->priv;
 
-  if (priv->mpris_client_proxy == NULL && !priv->connecting)
-    start_mpris_proxy (self, name);
-  else
-    self->priv->other_players = g_slist_prepend (self->priv->other_players, g_strdup (name));
+  priv->other_players = g_slist_prepend (priv->other_players, g_strdup (name));
+  mpris_player_try_connect (self);
 }
 
 static void
@@ -167,6 +197,15 @@ mpris_player_vanished (GDBusConnection *connection,
 {
   MprisController *self = user_data;
   MprisControllerPrivate *priv = MPRIS_CONTROLLER (self)->priv;
+  GSList *elem;
+
+  elem = g_slist_find_custom (priv->other_players, name, (GCompareFunc) g_strcmp0);
+  if (elem)
+    {
+      priv->other_players = g_slist_remove_link (priv->other_players, elem);
+      g_free (elem->data);
+      g_slist_free_1 (elem);
+    }
 
   if (priv->mpris_client_proxy &&
       g_strcmp0 (name, g_dbus_proxy_get_name (priv->mpris_client_proxy)) == 0)
@@ -174,21 +213,7 @@ mpris_player_vanished (GDBusConnection *connection,
       g_clear_object (&priv->mpris_client_proxy);
       g_object_notify (user_data, "has-active-player");
 
-      /* take the next one if there's one */
-      if (self->priv->other_players && !priv->connecting)
-        {
-          GSList *first;
-          gchar *name;
-
-          first = self->priv->other_players;
-          name = first->data;
-
-          start_mpris_proxy (self, name);
-
-          self->priv->other_players = self->priv->other_players->next;
-          g_free (name);
-          g_slist_free_1 (first);
-        }
+      mpris_player_try_connect (self);
     }
 }