patch 7.4.1229
Problem:    "eval" and "expr" channel commands don't work yet.
Solution:   Implement them.  Update the error numbers.  Also add "redraw".
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 028af35..1321b7f 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -335,7 +335,6 @@
 static void	ex_redo(exarg_T *eap);
 static void	ex_later(exarg_T *eap);
 static void	ex_redir(exarg_T *eap);
-static void	ex_redraw(exarg_T *eap);
 static void	ex_redrawstatus(exarg_T *eap);
 static void	close_redir(void);
 static void	ex_mkrc(exarg_T *eap);
@@ -9466,7 +9465,7 @@
 /*
  * ":redraw": force redraw
  */
-    static void
+    void
 ex_redraw(exarg_T *eap)
 {
     int		r = RedrawingDisabled;