[ESS] what is font-lock-pre-idle-hook

[Stephen Eglen]

 > It has nothing to do with the ESS R buffer. i.e it has something to do
 > with loading .R files only. So if I load a .R file and I edited outside
 > the buffer (e.g. through pico or something) I get the message.
 > 
 > shortest example:
 > touch temp.R
 > xemacs temp.R
 > ls > temp.R # in gnome-terminal or something and go back to xemacs
 > Mx revert-buffer

Thanks for this - I can now reproduce the warning; will investigate
sometime - although it is a minor warning, it may have consequences
elsewhere.

Stephen