server: Valid rects are in parent coordinates.
diff --git a/server/protocol.def b/server/protocol.def
index 21cae9c..321a933 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -2336,7 +2336,7 @@
     user_handle_t  previous;      /* previous window in Z order */
     rectangle_t    window;        /* window rectangle (in parent coords) */
     rectangle_t    client;        /* client rectangle (in parent coords) */
-    VARARG(valid,rectangles);     /* valid rectangles from WM_NCCALCSIZE (in client coords) */
+    VARARG(valid,rectangles);     /* valid rectangles from WM_NCCALCSIZE (in parent coords) */
 @REPLY
     unsigned int   new_style;     /* new window style */
     unsigned int   new_ex_style;  /* new window extended style */