ResolvedLayoutIR carried a page/system tree and three flat primitive arrays
with nothing joining them, so a canvas wanting to re-tessellate one damaged
system had to infer ownership spatially — ambiguous exactly where it matters,
at cross-system slurs and boundary-straddling strokes. The partition was
never missing, though: casting-off computes it (system_of_slot, stroke_system,
curve_system) and the fold into ResolvedLayoutIR dropped it. This publishes
it instead of inferring it, so the answer is exact.
ResolvedSystem gains PrimitiveIndices — u32 index lists into the layout's flat
glyphs/strokes/curves — and ResolvedLayoutIR gains an unowned bucket of the
same shape. No primitive is split, merged, reordered, or renumbered; the flat
arrays are exactly what they were. The partition is total and disjoint: for
each array, every system's list plus the unowned bucket covers 0..len exactly
once, tested directly rather than assumed from construction.
Unowned is a first-class bucket with a real producer. The stub solver resolves
no per-system geometry — one default-rect system per region — so it publishes
every primitive unowned rather than fabricating an attribution it never
computed. Cross-system primitives need no special case: casting-off already
splits a spanning stroke or curve into per-system segments carrying
SYSTEM_CONTINUATION_SYNTHESIS provenance, and each segment is owned by the
system it was split into, not by the source's.
Ownership is excluded from the canonical encoding, for the reason vertical_band
already is: it draws nothing, so two layouts differing only in it are the same
rendered layout and hash alike. Encoding it would make the fingerprint more
fragile than the rendering it fingerprints — a casting-off refactor that
re-partitions without moving a pixel would become a byte-level break for
something no renderer and no conformance claim can observe. Verified against
main: all eight reference fixtures produce byte-identical canonical layouts,
and all five GUI goldens are untouched.
One derivation, structurally. The quality census consumed its own copy of the
glyph-to-system rule, and so did vertical_raw's system_of_glyph closure; both
now read the published glyph_system. That left CastLayout::system_of_slot with
no consumer outside the casting pass, so it is removed from the published
struct — a future consumer cannot grow a third copy of the rule, because the
raw material is no longer there. The per-glyph answer travels; the derivation
does not.
Six mutations, each killed and coordinator-re-verified independently: dropping
an index from a system's list, coercing unowned onto system 0, an off-by-one
system index, publishing a constant attribution, attributing a continuation to
its source's system, and encoding ownership into the canonical bytes. The
fourth is the one that proves the single-derivation claim rather than asserting
it — it kills three quality tests, two of which survived it before
vertical_raw was migrated.
Gate: 34 suites / 1341 tests / 0 failed, conformance 9/9 with golden-gate and
8/8 without, requirement labels 6/6 at 212/282/282, clippy 0, five goldens
byte-identical.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Levi Neuwirth
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