Fix T82607: crash cancelling Cycles render during adaptive subdivision update

Now that the Blender sync mechanism deletes nodes from the scene, we need to
ensure scene update is stopped before we do this.

Also add some more early out in scene geometry update to ensure we do not
continue working on incomplete geometry data, though that was not the cause of
this crash.

1 files changed, 1 insertions, 0 deletions

diff --git a/intern/cycles/render/session.h b/intern/cycles/render/session.h
index a22bf7731ae..a52082bd8cb 100644
--- a/intern/cycles/render/session.h
+++ b/intern/cycles/render/session.h
@@ -146,6 +146,7 @@ class Session {
   ~Session();
 
   void start();
+  void cancel();
   bool draw(BufferParams &params, DeviceDrawParams &draw_params);
   void wait();