Description:
------------
The php function mkdir() does not apply the group sticky bit on folders created.  The php function chmod() is capable of doing this.

Previous, closed, bug reports show that mkdir() premitted sticky bits in the past when chmod() did not.

All of my safe_ variables are off:

[mjohansson@host tmp]$ php -r 'phpinfo();' | grep ^safe
safe_mode => Off => Off
safe_mode_exec_dir => no value => no value
safe_mode_gid => Off => Off
safe_mode_include_dir => no value => no value
safe_mode_allowed_env_vars => PHP_ => PHP_
safe_mode_protected_env_vars => LD_LIBRARY_PATH => LD_LIBRARY_PATH


Reproduce code:
---------------
rm -rf test2 test3;
php -r '
  umask(0);
  mkdir("test2", 02770);
  mkdir("test3",02770);
  chmod("test3",02770);';
ls -lad test2 test3

Expected result:
----------------
drwxrws--- 2 mjohansson mjohansson 4096 Feb 28 13:05 test2
drwxrws--- 2 mjohansson mjohansson 4096 Feb 28 13:05 test3

Actual result:
--------------
drwxrwx--- 2 mjohansson mjohansson 4096 Feb 28 13:05 test2
drwxrws--- 2 mjohansson mjohansson 4096 Feb 28 13:05 test3