(completion-root-regexp): New defvar.

(completion-setup-function): Use it instead of a literal string.

diff --git a/lisp/simple.el b/lisp/simple.el
index 1e112b1be74f3f124b0ec1c3428fbf23529346d2..b52220d542b89308a49a9dd4f09dd7f8bbdac622 100644 (file)
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4304,6 +4304,12 @@ make the common parts less visible than normal, so that the rest
 of the differing parts is, by contrast, slightly highlighted."
   :group 'completion)
 
+;; This is for packages that need to bind it to a non-default regexp
+;; in order to make the first-differing character highlight work
+;; to their liking
+(defvar completion-root-regexp "^/"
+  "Regexp to use in `completion-setup-function' to find the root directory.")
+
 (defun completion-setup-function ()
   (let ((mainbuf (current-buffer))
        (mbuf-contents (minibuffer-contents)))
@@ -4332,7 +4338,7 @@ of the differing parts is, by contrast, slightly highlighted."
                (with-current-buffer mainbuf
                  (save-excursion
                    (goto-char (point-max))
-                   (skip-chars-backward "^/")
+                   (skip-chars-backward completion-root-regexp)
                    (- (point) (minibuffer-prompt-end)))))
        ;; Otherwise, in minibuffer, the whole input is being completed.
        (if (minibufferp mainbuf)