fix: negation of MIN_VALUE wraps to match sigma-state#870
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…/Long) sigma-rust's `Negation` eval ran every numeric width through `checked_neg`, erroring when negating a fixed-width MIN_VALUE (`-(i8::MIN)` … `-(i64::MIN)`). sigma-state 6.0.3 negates fixed-width ints with the unchecked numeric `negate` (`ast/trees.scala` Negation.eval), so `-MIN == MIN` via two's-complement wrap, no error. A script that negates a context-/register-derived MIN is therefore accepted by the JVM but rejected by sigma-rust -- a latent consensus fork (never observed on mainnet, since live scripts don't negate MIN). Negate Byte/Short/Int/Long with `wrapping_neg`; keep `BigInt256` on `checked_neg` -- sigma-state's 256-bit BigInt also overflows negating its MIN (`-(2^255)`), so both sides error there. Verified against SANTA's JVM-blessed v5 vectors (`Numeric_Negation_equivalence.json`: `-128#0`, `-32768#9`, `-2147483648#18`, `-9223372036854775808#26` -> MIN with `error:null`). New test `negation_of_min_value_wraps_to_self` asserts the four widths wrap and `BigInt256::min_value()` still errors. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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Negationran every numeric width throughchecked_neg, erroring when negating a fixed-width MIN_VALUE. sigma-state 6.0.3 negates fixed-width ints unchecked (ast/trees.scalaNegation.eval), so-MIN == MIN(two's-complement wrap, no error) — a script negating a MIN is accepted by the JVM but rejected here: a latent consensus fork (not seen on mainnet).Fix:
wrapping_negfor Byte/Short/Int/Long;BigInt256stays checked (its 256-bit MIN overflows on the JVM too).Verified against JVM-blessed v5 vectors (LanguageSpecificationV5 Numeric_Negation); new
negation_of_min_value_wraps_to_selftest asserts the 4 widths wrap and BigInt256 still errors.