Introduce a time-of-check-time-of-use (TOCTOU) save file handler, this makes sure that from the time we check it is available until we get the file handler that no one attempted to put in a soft / hard link instead of what we checked for.
Introduce a time-of-check-time-of-use (TOCTOU) save file handler, this makes sure that from the time we check it is available until we get the file handler that no one attempted to put in a soft / hard link instead of what we checked for.

Further improves on #18056

# Port from tag PEAR-1.9.3

git-svn-id: 4b064e69dc630d28214c1e1442d27300cccf8e9a@309043 c90b9560-bf6c-de11-be94-00142212c4b1

DQNEO/PEAR_Exception