ZF-12047: Zend_Cache_Backend_File cache_file_umask and hashed_directory_umask are not umasks but octal permissions
The documentation and class uses the name "umask" for what is not an umask (see umask(2) man page for the definition : "umask() sets the calling process's file mode creation mask (umask) to mask & 0777"). Rather, the Zend_Cache_Backend_File uses the option "cache_file_umask" to chmod (http://php.net/chmod) the file. In effect this is an octal permission definition rather than a umask.
This is quite misleading.