libnm: Complete activation when ActiveConnection abruptly disappears

A NMActiveConnection may disappear before a match with NMDevice is found. In
such case recheck_pending_activations() would never call the activation
callback and the client would hang indefinitely:

libnm-Message: PC: (0x95bf088) NMManager:active-connections => '['/org/freedesktop/NetworkManager/ActiveConnection/225']' (ao / NMActiveConnection)
libnm-Message: PC: (0x95bf088) NMManager:activating-connection => ''/'' (o / NMActiveConnection)
libnm-Message: PC: (0x95d0a28) NMActiveConnection:state => '4' (u)
libnm-Message: PC: (0x95d0a28) NMActiveConnection:devices => '[]' (ao / NMDevice)
libnm-Message: PC: (0x95bf088) NMManager:active-connections => '[]' (ao / NMActiveConnection)
*hang*

Let's listen for active-connection-removed and tear down the activation with
an error if the removed connection is one we're activating.

1 files changed, 22 insertions, 0 deletions

diff --git a/libnm/nm-manager.c b/libnm/nm-manager.c
index 2f243ceff2..20f1458f3e 100644
--- a/libnm/nm-manager.c
+++ b/libnm/nm-manager.c
@@ -742,6 +742,8 @@ typedef struct {
 	char *new_connection_path;
 } ActivateInfo;
 
+static void active_removed (NMObject *object, NMActiveConnection *active, gpointer user_data);
+
 static void
 activate_info_complete (ActivateInfo *info,
                         NMActiveConnection *active,
@@ -749,6 +751,7 @@ activate_info_complete (ActivateInfo *info,
 {
 	NMManagerPrivate *priv = NM_MANAGER_GET_PRIVATE (info->manager);
 
+	g_signal_handlers_disconnect_by_func (info->manager, G_CALLBACK (active_removed), info);
 	if (active)
 		g_simple_async_result_set_op_res_gpointer (info->simple, g_object_ref (active), g_object_unref);
 	else
@@ -836,6 +839,22 @@ activation_cancelled (GCancellable *cancellable,
 }
 
 static void
+active_removed (NMObject *object, NMActiveConnection *active, gpointer user_data)
+{
+	ActivateInfo *info = user_data;
+	GError *error = NULL;
+
+	if (strcmp (info->active_path, nm_object_get_path (NM_OBJECT (active))))
+		return;
+
+	error = g_error_new_literal (NM_CLIENT_ERROR,
+	                             NM_CLIENT_ERROR_FAILED,
+	                             _("Active connection could not be attached to the device"));
+	activate_info_complete (info, NULL, error);
+	g_clear_error (&error);
+}
+
+static void
 activate_cb (GObject *object,
              GAsyncResult *result,
              gpointer user_data)
@@ -851,6 +870,9 @@ activate_cb (GObject *object,
 			                                       G_CALLBACK (activation_cancelled), info);
 		}
 
+		g_signal_connect (info->manager, "active-connection-removed",
+		                  G_CALLBACK (active_removed), info);
+
 		recheck_pending_activations (info->manager);
 	} else {
 		g_dbus_error_strip_remote_error (error);