Re-review of the fix commit returned MERGEABLE-WITH-NITS. It verified the gate is
now complete by enumerating the writers itself (no fourth persisting writer) and
proved B2's fix works by writing throwaway handler tests — which was also its
point: the fix shipped with none.
B2 was create and update silently DISAGREEING on the same input, and the fix
re-established agreement with nothing pinning it. Both paths are now driven from
one shared case list, plus an explicit test that create and update agree on every
case — the per-path tests would both have passed while the two diverged, which is
how the bug existed in the first place. Non-vacuity proven: inverting only the
update path's validation fails 10 of 20 on a clean build (0 errors, so not a
stale-dll pass), and the agreement test is among the failures.
The rest is my own prose contradicting my own code. The commit that added
EffectiveWeight removed the weight filter, then left four statements asserting a
0-weight source "is filtered out" — two of them authored by that same commit,
including the stated justification for Minimum=1 in MultiCollectionItemWeight.
A future agent could have read that and deleted the clamp or the floor as
redundant; they are belt-and-braces and neither is. Corrected to describe what the
code now does: the gate refuses input that means nothing on a share-of-airtime
scale, the clamp protects rows predating the gate.
Also corrected the writer count in the very bullet whose lesson is "grep every
writer of the field": ReplaceBlockItems writes BlockItem.PlaybackOrder, not
PlaylistItem.PlaybackOrder. There are TWO persisting writers of PlaylistItem's,
and the correction itself had miscounted by conflating the two fields — so the
lesson now says to grep each field separately.
Core.Tests 565 passed, ErsatzTV.Tests 1673 passed, 0 failed.
Refs #70
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
