Moved debug test from %STREAM-UNREAD-CHAR to STREAM-UNREAD-CHAR.

Signed-off-by: Stelian Ionescu <sionescu@common-lisp.net>

sockets/gray-stream-methods.lisp

@@ -450,14 +450,7 @@
         (char str 0)))))
 
 (defun %stream-unread-char (stream)
-  ;; unreading anything but the latest character is wrong,
-  ;; but checking is not mandated by the standard
   (declare (type active-socket stream))
-  #+iolib-debug
-  (progn
-    (%stream-unread-char stream)
-    (unless (ignore-errors (eql (stream-read-char stream) character))
-      (error "Trying to unread wrong character ~S" character)))
   (with-accessors ((ib input-buffer-of)
                    (unread-index ibuf-unread-index-of)) stream
     (symbol-macrolet ((start (iobuf-start ib)))
@@ -469,7 +462,16 @@
   nil)
 
 (defmethod stream-unread-char ((stream active-socket) character)
+  ;; unreading anything but the latest character is wrong,
+  ;; but checking is not mandated by the standard
+  #+iolib-debug
+  (progn
+    (%stream-unread-char stream)
+    (unless (ignore-errors (eql (stream-read-char stream) character))
+      (error "Trying to unread wrong character ~S" character)))
+  #-iolib-debug
   (declare (ignore character))
+  #-iolib-debug
   (%stream-unread-char stream))
 
 (defmethod stream-peek-char ((stream active-socket))