Steps to reproduce:
- Start Blender with default scene, set renderer to Cycles
- Enable vector pass
- Enable motion blur
- Set Breakpoint on the first continue in BlenderSync::sync_render_passes
- Render again
Both renders should hit the breakpoint.
The first render hits the breakpoint, the second doesn't.
blender_sync.cpp is doing things in the wrong order. BlenderSync::sync_render_passes() checks the scene->integrator->motion_blur flag, but that gets synced later.