Previously, `fd_readdir` was truncating directory entry names based on the
calculation of `min(name_len, buf_len - bufused)`, but `bufused` was not being
updated after writing in the `dirent` structure to the buffer.
This allowed `bufused` to be incremented beyond `buf_len` and returned as the
number of bytes written to the buffer, which is invalid.
This fix adjusts `bufused` when the buffer is written to for the `dirent` so
that name truncation happens as expected.
Fixes#2618.
the original C implementation was derived directly from cloudabi-utils.
that implementation is no longer in tree.
acfoltzer's initial Rust implementation included a path_open function
that was ported from cloudabi-utils. this rewrite of wasi-common has
completely delegated all path lookup functionality to cap-std (in the
cap-std-sync impls), and cap-std itself has a completely re-designed
method of path resolution.
This makes fstat work for stdout, stdin and stderr as expected.
This seemed like the only reasonable functions to implement from the
filestat_* set, for stdout, stdin and stderr.
Fixes#2515
Android always has `utimensat` available, so it is not necessary (or
possible, for that matter) to emulate it. Mark the fallback path as
`unreachable!()`.
`fd_readdir` returns a "bufused" value, which indicates the number of
bytes read into the buffer. WASI libc expects this value to be equal
to the size of the buffer if the end of the directory has not yet
been scanned.
Previously, wasi-common's `fd_readdir` was writing as many complete
entries as it could fit and then stopping, but this meant it was
returning size less than the buffer size even when the directory had
more entries. This patch makes it continue writing up until the end
of the buffer, and return that number of bytes, to let WASI libc
know that there's more to be read.
Fixes#2493.
