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Short right lists recycle their first element instead of null padding · case 05

Short right lists recycle their first element instead of null padding.

Member previewVariant 5 · 3 implementations · 7 checks per implementation

Case contract

Zip two optional lists within each parent row using longest-list semantics and zero-based ordinals. Missing positions become None; two empty or null lists yield one outer placeholder with ordinal None.

Why this case matters

A bounded deterministic data engine model makes representation and changelog faults reproducible.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
longer left	`[[5, 0, 6, 8], [5, 1, 7, 8]]`	`[[5, 0, 6, 8], [5, 1, 7, null]]`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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