With this patch - command line arguments [--frame-start, --frame-end, --frame-jump] no longer write into the scene.
Instead, they modify local variables in creator_args.c which override the scene's values (when set),
the overrides are reset on loading a new blend file or scene switching.
- Setting frame range messing with sequencer rendering (reported as T52583)
- Changes to the render in the case of scripts using the start/end frame in their operations.
Since this is an obscure bug, submitting to get second opinion.
The main down-side to this change is existing usage that relies on existing arguments modifying the scene. Setting the frame range then baking physics for eg.
Note updated patch to avoid an error when loading a blend file or switching a scene is done without command line arguments, otherwise this wont work:
blender -b foo.blend -s 1 -e 20 -a --python script_that_loads_a_blend.py -a