+(defun unescape-uri-field (query)
+ "Unescape non-alphanumeric characters for URI fields"
+ (declare (simple-string query)
+ (optimize (speed 3) (safety 0) (space 0)))
+ (do* ((count (count-string-char query #\%))
+ (len (length query))
+ (new-len (- len (* 2 count)))
+ (str (make-string new-len))
+ (spos 0 (1+ spos))
+ (dpos 0 (1+ dpos)))
+ ((= spos len) str)
+ (declare (fixnum count len new-len spos dpos)
+ (simple-string str))
+ (let ((ch (schar query spos)))
+ (if (char= #\% ch)
+ (let ((c1 (charhex (schar query (1+ spos))))
+ (c2 (charhex (schar query (+ spos 2)))))
+ (declare (fixnum c1 c2))
+ (setf (schar str dpos)
+ (code-char (logior c2 (ash c1 4))))
+ (incf spos 2))
+ (setf (schar str dpos) ch)))))
+
+