Windows File::truncate silently wraps u64 > i64::MAX to negative EOF

[SebTardif]

Bug

library/std/src/sys/fs/windows.rs File::truncate does size as i64 for FILE_END_OF_FILE_INFO::EndOfFile. Values above i64::MAX wrap to negative sizes, which is not a valid user-facing contract.

Origin

Windows FS port used a direct cast; Unix uses try_into() for off_t/off64_t and returns InvalidInput on overflow.

Impact

Caller-controlled sizes from untrusted configs/protocols (object stores, archives, IPC) can pass huge u64 values and get wrong/erroneous truncation behavior instead of a clean error. Availability/correctness issue on Windows only.

Fix

size.try_into::<i64>() with io::ErrorKind::InvalidInput on failure, matching Unix.