The arr[i].f=src legacy assign block enumerated scalar field-type arms then fell to a 1-word scalar default, so a non-call aggregate source (ident/dot/index) cgexpr'd only its first word into AX and stored one eightbyte — silent on BOTH stages (byte-id blind). The non-indexed bases (local/deref/chained/global) reach the general assign resolver's canonical aggargsrcaddr+aggcopy; the indexed arm short-circuited before it. Route the indexed base through the block's own proven &arr[i] spine into the same aggargsrcaddr+aggcopy emitters (DRY — no third copy), dual-site symmetric. Unlike #11's in-cap arm, the source is a memory address so aggcopy is a pure memcpy: float bits and the sub-8 tail transport verbatim, no loud-stop needed. Did not fall through to the general resolver because its cgplaceaddr N_INDEX arm rejects a *[N]S (TY_PTR) base (latent resolver gap, filed separately).
Contained to the indexed base + non-call aggregate-field rhs; value-asserting pins redden under each stage's independent revert.
Hojun-Cho
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