[gnome-builder] code: add g_critical() if invariant is not met

[Christian Hergert <chergert src gnome org>]

commit 0c78785566c8ecc9a2f8e4881d5fa9ed45717ddf
Author: Christian Hergert <chergert redhat com>
Date:   Sat Apr 27 11:14:38 2019 -0700

    code: add g_critical() if invariant is not met

 src/libide/code/ide-buffer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/src/libide/code/ide-buffer.c b/src/libide/code/ide-buffer.c
index 3eec82765..f063634f8 100644
--- a/src/libide/code/ide-buffer.c
+++ b/src/libide/code/ide-buffer.c
@@ -1448,8 +1448,10 @@ ide_buffer_save_file_cb (GObject      *object,
                                          &closure);
     }
 
-  if (self->buffer_manager)
+  if (self->buffer_manager != NULL)
     _ide_buffer_manager_buffer_saved (self->buffer_manager, self);
+  else
+    g_critical ("Attempt to save buffer without access to buffer-manager");
 
   ide_task_return_boolean (task, TRUE);