The temporary file is made read-only before the rename. When the rename
fails, Windows refuses to remove a read-only file, so the temporary copy
stayed in the cache directory. Give the owner write permission back
before removing it. The failure test now clears its cache directory,
including read-only files, before and after it runs, so it can run
again in the same directory.
Writing and reading the cached CA_LIST.cer used the throwing filesystem
and stream calls. Tests that share the cache directory raced on the
rename over the cached file, and on Windows the resulting
filesystem_error cannot be delivered through libkernel frames, so the
test process died. Use the error_code overloads, read in chunks that
set the stream error state, treat a lost rename race as success when the
cached file already holds the bundle, and answer an unavailable list
with no file instead of caching the failure.
The new test blocks the cache directory and the cached file in turn and
expects the open to fail with ENOENT, then to succeed once unblocked.
Dean Galvin