session sid_regexp in error length

[RicherYang]

CI 3.1.1 set the session ID must at less length 40 letter.( _sid_regexp )

But when hash_function = 1 (SHA1) the session_id() is 160-bit digest.
when hash_bits_per_character = 4 it goto 40 char
when hash_bits_per_character = 5 it goto 32 char
when hash_bits_per_character = 6 it goto 27 char

[narfbg]

Please test to see if 2f76087 really fixes this.

[RicherYang]

that can't fix the _sid_regexp error.
BUT I get a new error " Notice: Undefined variable: bits "

My system is php 7.0.11 ( PHP_VERSION_ID 70011 )
in php.ini set session.hash_function = 1 and session.hash_bits_per_character = 5

in the fix use $sid_length = $bits * $bits_per_character; to calculate the sid length.
may change to $sid_length = (int) ceil($bits / $bits_per_character);

[narfbg]

How about now?

[RicherYang]

It work nice on my system.

[narfbg]

Great, thanks.