* files.el (parse-colon-path): Use split-string.

Fixes: debbugs:12351

lisp/ChangeLog

 2012-09-16  Chong Yidong  <cyd@gnu.org>
+	* files.el (parse-colon-path): Use split-string (Bug#12351).
+
 	* window.el (special-display-popup-frame): Doc fix (Bug#8853).
 	(display-buffer-function): Mark as obsolete.

lisp/files.el

@@ -658,22 +658,13 @@ Not actually set up until the first time you use it.")
 
 (defun parse-colon-path (search-path)
   "Explode a search path into a list of directory names.
-Directories are separated by occurrences of `path-separator'
-\(which is colon in GNU and GNU-like systems)."
-  ;; We could use split-string here.
-  (and search-path
-       (let (cd-list (cd-start 0) cd-colon)
-	 (setq search-path (concat search-path path-separator))
-	 (while (setq cd-colon (string-match path-separator search-path cd-start))
-	   (setq cd-list
-		 (nconc cd-list
-			(list (if (= cd-start cd-colon)
-				   nil
-				(substitute-in-file-name
-				 (file-name-as-directory
-				  (substring search-path cd-start cd-colon)))))))
-	   (setq cd-start (+ cd-colon 1)))
-	 cd-list)))
+Directories are separated by `path-separator' (which is colon in
+GNU and Unix systems).  Substitute environment variables into the
+resulting list of directory names."
+  (when (stringp search-path)
+    (mapcar (lambda (f)
+	      (substitute-in-file-name (file-name-as-directory f)))
+	    (split-string search-path path-separator t))))
 
 (defun cd-absolute (dir)
   "Change current directory to given absolute file name DIR."