[glib/cherry-pick-e48a3920-2] Merge branch 'fdonotif-segfault-fix' into 'master'

[Philip Withnall <pwithnall src gnome org>]

commit 1b37bcd2fb4cdcaa80a894d4f86e0a28f0169cab
Author: Philip Withnall <philip tecnocode co uk>
Date:   Wed Jun 13 09:27:11 2018 +0000

    Merge branch 'fdonotif-segfault-fix' into 'master'
    
    gfdonotificationbackend: Fix possible invalid pointer in dbus callback
    
    See merge request GNOME/glib!90
    
    (cherry picked from commit e48a3920d4e77249dd400a7830d48a0dbedb9087)
    
    57e070f8 gfdonotificationbackend: Fix possible invalid pointer in dbus callback

 gio/gfdonotificationbackend.c | 55 ++++++++++++++++++++++++++-----------------
 1 file changed, 34 insertions(+), 21 deletions(-)
---
diff --git a/gio/gfdonotificationbackend.c b/gio/gfdonotificationbackend.c
index a0d481433..ab5329497 100644
--- a/gio/gfdonotificationbackend.c
+++ b/gio/gfdonotificationbackend.c
@@ -62,7 +62,6 @@ typedef struct
   GVariant *default_action_target;
 } FreedesktopNotification;
 
-
 static void
 freedesktop_notification_free (gpointer data)
 {
@@ -76,6 +75,24 @@ freedesktop_notification_free (gpointer data)
   g_slice_free (FreedesktopNotification, n);
 }
 
+static FreedesktopNotification *
+freedesktop_notification_new (GFdoNotificationBackend *backend,
+                              const gchar             *id,
+                              GNotification           *notification)
+{
+  FreedesktopNotification *n;
+
+  n = g_slice_new0 (FreedesktopNotification);
+  n->backend = backend;
+  n->id = g_strdup (id);
+  n->notify_id = 0;
+  g_notification_get_default_action (notification,
+                                     &n->default_action,
+                                     &n->default_action_target);
+
+  return n;
+}
+
 static FreedesktopNotification *
 g_fdo_notification_backend_find_notification (GFdoNotificationBackend *backend,
                                               const gchar             *id)
@@ -319,8 +336,19 @@ notification_sent (GObject      *source_object,
   val = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source_object), result, &error);
   if (val)
     {
+      GFdoNotificationBackend *backend = n->backend;
+      FreedesktopNotification *match;
+
       g_variant_get (val, "(u)", &n->notify_id);
       g_variant_unref (val);
+
+      match = g_fdo_notification_backend_find_notification_by_notify_id (backend, n->notify_id);
+      if (match != NULL)
+        {
+          backend->notifications = g_slist_remove (backend->notifications, match);
+          freedesktop_notification_free (match);
+        }
+      backend->notifications = g_slist_prepend (backend->notifications, n);
     }
   else
     {
@@ -331,9 +359,7 @@ notification_sent (GObject      *source_object,
           warning_printed = TRUE;
         }
 
-      n->backend->notifications = g_slist_remove (n->backend->notifications, n);
       freedesktop_notification_free (n);
-
       g_error_free (error);
     }
 }
@@ -378,7 +404,7 @@ g_fdo_notification_backend_send_notification (GNotificationBackend *backend,
                                               GNotification        *notification)
 {
   GFdoNotificationBackend *self = G_FDO_NOTIFICATION_BACKEND (backend);
-  FreedesktopNotification *n;
+  FreedesktopNotification *n, *tmp;
 
   if (self->notify_subscription == 0)
     {
@@ -391,24 +417,11 @@ g_fdo_notification_backend_send_notification (GNotificationBackend *backend,
                                             notify_signal, backend, NULL);
     }
 
-  n = g_fdo_notification_backend_find_notification (self, id);
-  if (n == NULL)
-    {
-      n = g_slice_new0 (FreedesktopNotification);
-      n->backend = self;
-      n->id = g_strdup (id);
-      n->notify_id = 0;
-
-      n->backend->notifications = g_slist_prepend (n->backend->notifications, n);
-    }
-  else
-    {
-      /* Only clear default action. All other fields are still valid */
-      g_clear_pointer (&n->default_action, g_free);
-      g_clear_pointer (&n->default_action_target, g_variant_unref);
-    }
+  n = freedesktop_notification_new (self, id, notification);
 
-  g_notification_get_default_action (notification, &n->default_action, &n->default_action_target);
+  tmp = g_fdo_notification_backend_find_notification (self, id);
+  if (tmp)
+    n->notify_id = tmp->notify_id;
 
   call_notify (backend->dbus_connection, backend->application, n->notify_id, notification, 
notification_sent, n);
 }