Yes, you patch supersedes issue16956 patch. Added new comments on Rietveld for lnotab_notes.txt. I afraid this patch can cause problems with code tracing where it is assumed that lines are increased monotonically and *instr_lb <= frame->f_lasti < *instr_ub. We should carefully analyze the effect of the patch on the tracing. Before committing you must ask Guido for approval. AFAIK his had objections against code transformations that make debugging harder.