On Windows, WriteFileAtomically replaces a cache entry with a POSIX
rename so that readers and mappings of the old entry keep working.
Through an SMB share that rename fails with ERROR_INVALID_PARAMETER, and
the plain rename it falls back to is refused while the destination is
open or mapped, so agc_shader_disk_cache and shader_cache_file_read
failed with their temporary directory on such a share (#10833).
The POSIX rename moves into PosixReplaceByHandle, unchanged, and
PosixReplaceUnsupported probes it in a directory. Where it reports that
error, the tests skip only the replacements of an entry that a reader
holds open or the cache has mapped, and the disk cache test's cleanup
leaves its directory behind when the POSIX delete fails the same way;
any other failure still fails them. shader_cache_file_read also builds
its \?\ alias of a UNC path as \?\UNC\server\share. The limitation is
recorded in the shader debt file.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
