`-u`/`update-head-ok` unsupported on pull

According to the documentation these options are supported:
$ git help pull | grep -e '--update-head-ok'
       -u, --update-head-ok

However: $ git pull --update-head-ok error: unknown option `update-head-ok'

Using: $ git --version git version 2.6.1 $ pacman --query --info git | grep ^Version Version : 2.6.1-1

Am I missing something? The manual seems to be for the right version:

$ git help pull | tail -n1 | tr -s ' ' Git 2.6.1 10/06/2015 GIT-PULL(1)

I'm running the system installed Git:

$ type -a git git is /usr/bin/git

Cheers Victor

+Paul Tan who rewrote git pull in C recently.

The manpage:
-u, --update-head-ok
           By default git fetch refuses to update the head which
corresponds to the current branch. This flag disables the check. This
is purely for the internal use for git pull to communicate with
           git fetch, and unless you are implementing your own
Porcelain you are not supposed to use it.

I guess we either need to update the manpage to remove that option then, or add it back in in case somebody actually uses it despite the warning in the man page?