a strange error has been occuring more and more in my mode (web-mode.el available on http://web-mode.org)

The error message is "Invalid search bound (wrong side of point)" and is triggered with a quite simple re-search-forward

(while (re-search-forward "<\\?\\|<%[#-!@]?\\|</?[#@]\\|[$#]{\\|{[#{%]\\|^%." end t) .......

I tried to grep in the lisp sources of emacs and didn't find anything (just a comment in cc-cmds.el).

Do you know where I can find some informations about this error ?

Could you tell me when this kind of error is triggered ?

Best

François-Xavier Bois