With per-sub-mesh declarations enabled, n201_01 decoded as a 2-part fragment 4 bytes
off. Both starts validate for the pivot — 0x32BA718 at pad 2 (earlier in file order,
so first-match took it) and the capture-proven 0x32BA71C at pad 0 — so the pivot
alone cannot separate them; at the early one two of four sub-meshes fall out as
out-of-range.
anchor_grouped_meshes now builds each accepted candidate and keeps the one that
explains the most of the declared pool: it returns immediately when a candidate
explains all n sub-meshes, else keeps the best partial, so it can never decode less
than first-match did. n201_01 lands on all four capture-proven offsets
(0x32BA71C / 0x32BEFF4 / 0x32C416C / 0x32C536C) and its two sibling copies take their
own pools, so the twin collapse is gone.
XBG7_SUBMESH_DECLS is therefore on by default (=0 reverts):
resources that never decode 85 -> 47
resources decoding in no container 63 -> 30
degenerate index runs 1 -> 1 (unchanged)
cross-container minority decodes 96 -> 96 (unchanged)
captured index runs, stage-02 93/93 (unchanged)
captured index runs, stage-05 124/128 -> 128/128
The last line is the point: the buffers the capture could not name are the n201
family, and they now decode and match the GPU's indices byte for byte. Suite green
including twin_pairs_do_not_share_a_buffer, apart from the pre-existing
known-failing cross-container consistency test.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NptfmpjdpNCKEez6d2xvA9
Claude (auto-RE)
3b35c48fce