[gnome-builder] flatpak: short circuit when flatpak is not used

[Christian Hergert <chergert src gnome org>]

commit 301239826191f51f61b81acb63e38ad6f29acb7b
Author: Christian Hergert <chergert redhat com>
Date:   Sat Dec 16 18:00:10 2017 -0800

    flatpak: short circuit when flatpak is not used
    
    If we are trying to update dependencies and we failed to locate
    the flatpak updater stage, just short-circuit.

 .../flatpak/gbp-flatpak-dependency-updater.c       |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/flatpak/gbp-flatpak-dependency-updater.c 
b/src/plugins/flatpak/gbp-flatpak-dependency-updater.c
index 6e40621..6d2ed51 100644
--- a/src/plugins/flatpak/gbp-flatpak-dependency-updater.c
+++ b/src/plugins/flatpak/gbp-flatpak-dependency-updater.c
@@ -98,8 +98,15 @@ gbp_flatpak_dependency_updater_update_async (IdeDependencyUpdater *updater,
 
   /* Find the downloads stage and tell it to download updates one time */
   ide_build_pipeline_foreach_stage (pipeline, find_download_stage_cb, &stage);
-  if (stage != NULL)
-    gbp_flatpak_download_stage_force_update (stage);
+
+  if (stage == NULL)
+    {
+      /* Synthesize success if they weren't using flatpak. */
+      g_task_return_boolean (task, TRUE);
+      return;
+    }
+
+  gbp_flatpak_download_stage_force_update (stage);
 
   /* Ensure downloads and everything past it is invalidated */
   ide_build_pipeline_invalidate_phase (pipeline, IDE_BUILD_PHASE_DOWNLOADS);