The MT stream initializer and its later dictionary update both encoded the
same three-way choice in C: copy a supplied dictionary, attach a borrowed
CDict, or install a raw prefix. The old code also embedded the required
release/clear-before-attach ordering in each callback wrapper. Project the
presence and raw-content flags into Rust, where the branch and ordering are
now explicit and tested. C retains only the private CDict allocation,
prefix-storage, context publication, and destruction callbacks, so the
configured C layouts and allocator behavior remain unchanged.
Test Plan:
- `ulimit -v 41943040; cargo +nightly fmt --manifest-path rust/Cargo.toml --all -- --check` -- passed
- `ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings` -- passed
- `git diff --check` and `rustfmt --edition 2021 --check` -- passed before commit
- Capped native and original-test verification remains pending for the complete batch.
ddidderr
b0e90c39e2