a8e64f9a22
PRs #147511 and #147595 ensured that any check for scene strip renders in the prefetch thread would also recurse into "sequencer-type" scene strips, but this introduced the potential for an infinite recursion. Fix by using `SeqRenderState` to detect such a recursion. Also remove unused `seqbasep` context member in `PrefetchJob`, and add a check for non-nullptr `Editing`, fixing a crash where the scene was present without an `Editing` counterpart. Pull Request: https://projects.blender.org/blender/blender/pulls/147949