julia

c947944d - inference: propagate `PartialStruct` for parametric struct construction (#61719)

inference: propagate `PartialStruct` for parametric struct construction (#61719) `abstract_eval_new` previously gated `PartialStruct` formation on `isconcretedispatch(rt)`. That's correct for fully-instantiated concrete struct construction, but it discards extended lattice information when `rt` is a partially-instantiated parametric type, e.g. `Some{OpaqueClosure{Tuple{Any}, T} where T}` or `Generator{Vector{Int}, F<:OpaqueClosure{Tuple{Int}, T} where T}`. Such types still have a well-defined field count and field types, so the per-field lattice elements (`PartialOpaque`, `Const`, `PartialStruct` of nested structs, …) carry strictly more precision than the declared field types — but without `PartialStruct` formation that precision is discarded at the construction site, and downstream `getfield` reads only recover the widened type. Loosen the gate to also accept the parametric case (`fcount !== nothing && nargs ≤ fcount`). `nothrow` and the `Const`-folding fast path remain gated on `isconcretedispatch(rt)` — those genuinely require the concrete result type — and the new non-concretedispatch arm falls back to `refine_partial_type(rt)` when no field refinement happens, mirroring the outer `else` branch. This complements the eager-body rt refinement (`abstract_eval_new_opaque_closure`) for an ongoing experiment in JETLS that runs inference statelessly against top-level chunks, where JETLS converts closures to opaque closures at re-lowering phase to workaround the closure name-resolution issues. Common code patterns wrap a closure in another struct (e.g. `map`'s implementation), and without this change the wrapping erased the `PartialOpaque` info, so a later call recovered only the widened `OpaqueClosure{argt, T} where T` and `abstract_call_unknown`'s OC fallback widened the result to `T<:Any`. With this change the `PartialStruct` carries the `PartialOpaque` field through in such cases, so the reading `getfield` hands `abstract_call_opaque_closure` the precise lattice element it needs. Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>