bug#14013: 24.3.50; dired-isearch-filenames-regexp is matching text outside filenames

[Stefan Monnier]

> To implement ^, I see no way other than special handling:
> when a regexp begins with ^, then after removing ^ from the regexp,
> call 'looking-at' at the beginning of the file name.

I don't know if we want to handle ^ specially, but if we do we can use
something like:

    (while (string-match "\\^" RE i)
      (setq i (match-end 0))
      (if (not (subregexp-context-p RE (match-beginning 0)))
          ;; The ^ is inside a char-range or escaped or something.
          nil
        (setq RE (replace-match (concat "\\(?:"
                                        directory-listing-before-filename-regexp
                                        "\\)")
                                t t RE))))


-- Stefan