fix: correct Vec::from_raw_parts element type in prqlc-c#5732
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The `result_destroy` function was using `*mut i8` as the element type when reconstructing the Vec for deallocation, but the original allocation was `Vec<Message>`. This mismatch causes undefined behavior because `Vec::from_raw_parts` requires the same type, alignment, and element size as the original allocation. Changed to `*mut Message` to match the original `Vec<Message>` allocation. Since `Message` is a `#[repr(C)]` struct with no `Drop` impl, the Vec drop simply deallocates the buffer without running element destructors, so there is no double-free risk with the manual field cleanup above. Closes #5731 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
result_destroywhereVec::from_raw_partswas called with*mut i8instead of*mut Message, causing undefined behavior due to mismatched element type, alignment, and size vs. the originalVec<Message>allocation.Closes #5731
Test plan
cargo build -p prqlc-ccompiles successfullycargo test -p prqlc-cpasses🤖 Generated with Claude Code