--- emacs-24.3/src/lisp.h
+++ emacs-24.3/src/lisp.h
@@ -3148,6 +3148,7 @@
 extern _Noreturn void error (const char *, ...) ATTRIBUTE_FORMAT_PRINTF (1, 2);
 extern _Noreturn void verror (const char *, va_list)
   ATTRIBUTE_FORMAT_PRINTF (1, 0);
+extern _Noreturn void user_error (const char *);
 extern Lisp_Object un_autoload (Lisp_Object);
 extern Lisp_Object call_debugger (Lisp_Object arg);
 extern void init_eval_once (void);
--- emacs-24.3/src/keyboard.c
+++ emacs-24.3/src/keyboard.c
@@ -782,7 +782,7 @@
   /* Handle throw from read_minibuf when using minibuffer
      while it's active but we're in another window.  */
   if (STRINGP (val))
-    xsignal1 (Qerror, val);
+    xsignal1 (Quser_error, val);
 
   return unbind_to (count, Qnil);
 }
@@ -1207,7 +1207,7 @@
   Fthrow (Qtop_level, Qnil);
 }
 
-static _Noreturn void
+_Noreturn void
 user_error (const char *msg)
 {
   xsignal1 (Quser_error, build_string (msg));
--- emacs-24.3/src/minibuf.c
+++ emacs-24.3/src/minibuf.c
@@ -449,7 +449,7 @@
       && minibuf_level > 0)
     {
       if (EQ (selected_window, minibuf_window))
-	error ("Command attempted to use minibuffer while in minibuffer");
+	user_error ("Command attempted to use minibuffer while in minibuffer");
       else
 	/* If we're in another window, cancel the minibuffer that's active.  */
 	Fthrow (Qexit,
--- emacs-24.3/src/undo.c
+++ emacs-24.3/src/undo.c
@@ -445,12 +445,6 @@
   unbind_to (count, Qnil);
 }
 
-static _Noreturn void
-user_error (const char *msg)
-{
-  xsignal1 (Quser_error, build_string (msg));
-}
-
 
 DEFUN ("primitive-undo", Fprimitive_undo, Sprimitive_undo, 2, 2, 0,
        doc: /* Undo N records from the front of the list LIST.