Previously, fd_prestat_get would return the length of the directory name + 1, for the null terminator. This isn't quite right, as WASI strings are not null-terminated, and instead always operate in terms of a pointer and a size.
If a consumer of fd_prestat_get with fd_prestat_dir_name wants this value as a null-terminated string, they need to null-terminate it themselves, which I reflected in the tests.
This probably hasn't been noticed before because if the consumer of uvwasi uses null-terminated strings, functions like strlen will still report the correct value, but this isn't the case for languages that don't null-terminate strings, with null being a valid string character.
This could be considered a breaking fix if someone relied on uvwasi reporting and subsequently copying over the null byte, but I'll leave that decision to @cjihrig.
Previously,
fd_prestat_getwould return the length of the directory name + 1, for the null terminator. This isn't quite right, as WASI strings are not null-terminated, and instead always operate in terms of a pointer and a size.If a consumer of
fd_prestat_getwithfd_prestat_dir_namewants this value as a null-terminated string, they need to null-terminate it themselves, which I reflected in the tests.This probably hasn't been noticed before because if the consumer of uvwasi uses null-terminated strings, functions like
strlenwill still report the correct value, but this isn't the case for languages that don't null-terminate strings, with null being a valid string character.This could be considered a breaking fix if someone relied on uvwasi reporting and subsequently copying over the null byte, but I'll leave that decision to @cjihrig.