Either I have a profound mis-understanding, or XEmacs (latest stable and beta) has a bug in the regular expression handling: (string-match "^\\|c" "") 0 ; ok (string-match "\\(^\\|c\\)" "") 0 ; ok (string-match "\\(?:^\\|c\\)" "") nil ; wtf? (string-match "\\(?:^\\|c\\)" "c") 0 ; ok (string-match "\\(?:c\\|^\\)" "") 0 ; ok ;; and even (string-match "\\(?:^\\)" "") nil ; wtf? ; but (string-match "\\(?:^\\)" "^") 0 In short, ^ seems to be mis-understood as a literal character when immediately following a shy grouping open. A few minutes later... The offending code is at_begline_loc_p() in regex.c, which hasn't been told about shy grouping. If you like, I can propose a fix, but if somebody else knows the regex code well (in particular all the bits that control syntax variations), that would be better;-) _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://lists.xemacs.org/mailman/listinfo/xemacs-beta