[BUG] No font lock in src blocks for shells in org-babel-shell-names (was Re: Font lock for org-babel shell scripts?)

[Matt]

Of the shells given in `org-babel-shell-names' (that is, "sh" "bash" "zsh" 
"fish" "csh" "ash" "dash" "ksh" "mksh" "posh"), only "sh" and "bash" have font 
locking in source blocks.

For example,

#+begin_src sh
  if [ -z $TEST ]; then
      echo Fontified
  fi
#+end_src

#+begin_src bash
  if [ -z $TEST ]; then
      echo Fontified
  fi
#+end_src

#+begin_src zsh
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src fish
  if [ -z $TEST ]; then
     echo No fontification
  fi
#+end_src

#+begin_src csh
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src ash
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src dash
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src ksh
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src mksh
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

#+begin_src posh
  if [ -z $TEST ]; then
      echo No fontification
  fi
#+end_src

 Does anyone know which function is responsible for re-fontifing source blocks?