Fix race in tp_channel_dispatch_operation_claim_with_async()

Claiming the CDO will result in MC destroying it, so we have to prepare it
before calling Claim(). (fdo #37280)

2 files changed, 24 insertions, 11 deletions

diff --git a/telepathy-glib/channel-dispatch-operation.c b/telepathy-glib/channel-dispatch-operation.c
index 12272288..340616ec 100644
--- a/telepathy-glib/channel-dispatch-operation.c
+++ b/telepathy-glib/channel-dispatch-operation.c
@@ -1394,7 +1394,7 @@ gboolean
 }
 
 static void
-claim_with_prepare_cb (GObject *source,
+claim_with_cb (GObject *source,
     GAsyncResult *result,
     gpointer user_data)
 {
@@ -1403,7 +1403,7 @@ claim_with_prepare_cb (GObject *source,
   GError *error = NULL;
   TpBaseClient *client;
 
-  if (!tp_proxy_prepare_finish (self, result, &error))
+  if (!tp_channel_dispatch_operation_claim_finish (self, result, &error))
     {
       g_simple_async_result_take_error (main_result, error);
       goto out;
@@ -1419,16 +1419,15 @@ out:
 }
 
 static void
-claim_with_cb (GObject *source,
+claim_with_prepare_cb (GObject *source,
     GAsyncResult *result,
     gpointer user_data)
 {
   TpChannelDispatchOperation *self = (TpChannelDispatchOperation *) source;
   GSimpleAsyncResult *main_result = user_data;
   GError *error = NULL;
-  GQuark features[] = { TP_CHANNEL_DISPATCH_OPERATION_FEATURE_CORE, 0 };
 
-  if (!tp_channel_dispatch_operation_claim_finish (self, result, &error))
+  if (!tp_proxy_prepare_finish (self, result, &error))
     {
       g_simple_async_result_take_error (main_result, error);
       g_simple_async_result_complete (main_result);
@@ -1436,11 +1435,10 @@ claim_with_cb (GObject *source,
       return;
     }
 
-  /* We have to prepare the CDO to be able to get the list of its channels */
-  tp_proxy_prepare_async (self, features, claim_with_prepare_cb,
-      main_result);
+  tp_channel_dispatch_operation_claim_async (self, claim_with_cb, main_result);
 }
 
+
 /**
  * tp_channel_dispatch_operation_claim_with_async:
  * @self: a #TpChannelDispatchOperation
@@ -1474,6 +1472,7 @@ tp_channel_dispatch_operation_claim_with_async (
     gpointer user_data)
 {
   GSimpleAsyncResult *result;
+  GQuark features[] = { TP_CHANNEL_DISPATCH_OPERATION_FEATURE_CORE, 0 };
 
   g_return_if_fail (TP_IS_CHANNEL_DISPATCH_OPERATION (self));
 
@@ -1484,8 +1483,10 @@ tp_channel_dispatch_operation_claim_with_async (
   g_simple_async_result_set_op_res_gpointer (result, g_object_ref (client),
       g_object_unref);
 
-  tp_channel_dispatch_operation_claim_async (self, claim_with_cb,
-      result);
+  /* We have to prepare the CDO to be able to get the list of its channels.
+   * We prepare it *before* calling Claim() as MC will destroy the CDO once it
+   * has been claimed. */
+  tp_proxy_prepare_async (self, features, claim_with_prepare_cb, result);
 }
 
 /**
diff --git a/tests/dbus/base-client.c b/tests/dbus/base-client.c
index 0fe60cd9..8263582b 100644
--- a/tests/dbus/base-client.c
+++ b/tests/dbus/base-client.c
@@ -258,7 +258,7 @@ teardown (Test *test,
     g_object_unref (test->text_chan_service_2);
   g_object_unref (test->text_chan_2);
 
-  g_object_unref (test->cdo_service);
+  tp_clear_object (&test->cdo_service);
 
   tp_cli_connection_run_disconnect (test->connection, -1, &test->error, NULL);
   g_assert_no_error (test->error);
@@ -1152,6 +1152,13 @@ claim_with_cb (GObject *source,
 }
 
 static void
+cdo_finished_cb (TpTestsSimpleChannelDispatchOperation *cdo,
+    Test *test)
+{
+  tp_clear_object (&test->cdo_service);
+}
+
+static void
 test_channel_dispatch_operation_claim_with_async (Test *test,
     gconstpointer data G_GNUC_UNUSED)
 {
@@ -1210,6 +1217,11 @@ test_channel_dispatch_operation_claim_with_async (Test *test,
   handled = tp_base_client_get_handled_channels (test->base_client);
   g_assert (handled == NULL);
 
+  /* Connect to CDO's Finished signal so we can remove it from the bus when
+   * it's claimed as MC would do. */
+  g_signal_connect (test->cdo_service, "finished",
+      G_CALLBACK (cdo_finished_cb), test);
+
   /* Claim the CDO, as the client is also a Handler, it is now handling the
    * channels */
   tp_channel_dispatch_operation_claim_with_async (cdo, test->base_client,