filelock: StrictSoftFileLock follows a symbolic link swapped in at <path>.filelock and creates claim files in a directory another local user chooses

StrictSoftFileLock and AsyncStrictSoftFileLock check .filelock the coordination directory that holds the lock's state with one lstat call on its name. lstat reports what a name is without following a symbolic link a file that redirects to another path. After that check, the code reaches...