read-file-name-electric-shadow-mode

[Eli Zaretskii]

I like this!

However, in this beginning of rfn-eshadow-setup-minibuffer:

    ;; This function goes on minibuffer-setup-hook
    (defun rfn-eshadow-setup-minibuffer ()
      "Set up a minibuffer for `read-file-name-electric-shadow-mode'.
    The prompt and initial input should already have been inserted."
      (when minibuffer-completing-file-name
        (setq rfn-eshadow-overlay
              (make-overlay (minibuffer-prompt-end) (minibuffer-prompt-end)))
        ;; Give rfn-eshadow-overlay the user's props.
        (let ((props
               (if window-system
                   read-file-name-electric-shadow-properties
                 read-file-name-electric-shadow-tty-properties)))
          (while props
            (overlay-put rfn-eshadow-overlay (pop props) (pop props))))

is there any reason why you used window-system rather than
display-color-p?  Don't we want users to use colors on a tty if
available?

Btw, I ran some tests with DOSish file names, and the code works
well.  Good job!