The negative-stat cache and the apr file-size cache memoize host
filesystem probe outcomes, but both were keyed with an ignore-case
comparer while the probes themselves (File.Exists/Directory.Exists/
FileInfo) are case-sensitive on Linux. That aliases distinct paths:
- stat("/app0/DATA.BIN") fails, the miss is cached, and a later
stat("/app0/Data.bin") is answered NOT_FOUND from the cache without
ever probing the disk - even though the file exists and the probe
would succeed.
- sceKernelAprResolveFilepathsToIdsAndFileSizes serves the cached size
of a case-distinct sibling file instead of the file's own size.
The registered-mount containment guard had the inverse problem: the
ignore-case StartsWith accepted a ".." path that resolves into a
sibling directory differing from the mount root only by case
("…/Save" vs "…/save"), letting guest I/O escape the mount.
All three sites now compare with the host filesystem's semantics:
ordinal-ignore-case on Windows, ordinal elsewhere. Windows behavior is
unchanged. Tests probe actual host filesystem behavior with real temp
files and skip their case-specific sections on case-insensitive hosts.
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