FileSession time is too short

[viweei]

FileSession time is too short, I found in the File

sessions.py at line 297

self.cache = FileSystemCache (cache_dir, threshold = threshold, mode = mode)

Missing parameters default_timeout, because FileSystemCache default value is 300 seconds.
look at

class FileSystemCache(BaseCache):
   """
   ....
   """
    #: used for temporary files by the FileSystemCache
    _fs_transaction_suffix = '.__wz_cache'

    def __init__(self, cache_dir, threshold=500, default_timeout=300, mode=0o600):
        BaseCache.__init__(self, default_timeout)
        self._path = cache_dir
        self._threshold = threshold
        self._mode = mode

So I think we should use Flask parameter "PERMANENT_SESSION_LIFETIME"

[fengsp]

We are always using PERMANENT_SESSION_LIFETIME so far.