(fill-comment-paragraph): Document 2006-12-24 change.

Suggested by Stefan Monnier.

diff --git a/lisp/textmodes/fill.el b/lisp/textmodes/fill.el
index e3250a6f7105befb2e809d4202ade87d39136738..21ee585ec11e69c0bb01b993d0d1ba06f9a42c54 100644 (file)
--- a/lisp/textmodes/fill.el
+++ b/lisp/textmodes/fill.el
@@ -838,14 +838,16 @@ can take care of filling.  JUSTIFY is used as in `fill-paragraph'."
             (commark
              (comment-string-strip (buffer-substring comstart comin) nil t))
             (comment-re
+             ;; `commark' is surrounded with arbitrary text (`\0' and `a')
+             ;;  to make sure it can be used as an optimization of
+             ;; `comment-start-skip' in the middle of a line.  For example,
+             ;; `commark' can't be used with the "@c" in TeXinfo (hence
+             ;; the `a') or with the "C" at BOL in Fortran (hence the `\0').
              (if (string-match comment-start-skip (concat "\0" commark "a"))
                  (concat "[ \t]*" (regexp-quote commark)
                          ;; Make sure we only match comments that use
                          ;; the exact same comment marker.
                          "[^" (substring commark -1) "]")
-               ;; If the commark needs to be followed by some special
-               ;; set of characters (like @c in TeXinfo), we can't
-               ;; rely just on `commark'.
                (concat "[ \t]*\\(?:" comment-start-skip "\\)")))
             (comment-fill-prefix       ; Compute a fill prefix.
              (save-excursion