Unset the environment variables associated with individual menu items

before invoking the kernel.

Quoting submitter:

The issue is with the new boot loader menu. It adds many loader variables
including ones that contain ANSI color escapes.

Obviously, these ANSI codes don't play well with serial consoles when
kenv(1) is executed without arguments (reports vary as to what happens,
but it's never pretty).

The net-effect is that kenv(1) no longer reports menu-related variables.

In essence, kenv(1) output should now appear the same as on RELENG_8
(which lacks the new boot loader and didn't use any such variables).
Thus, restoring serial console glory.

Submitted by:	Devin Teske <devin dott teske fisglobal.com>
MFC after:	2 weeks

1 files changed, 7 insertions, 3 deletions

diff --git a/sys/boot/forth/menu.4th.8 b/sys/boot/forth/menu.4th.8
index 55cbfd1..dc00af8 100644
--- a/sys/boot/forth/menu.4th.8
+++ b/sys/boot/forth/menu.4th.8
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd Aug 29, 2011
+.Dd Dec 27, 2011
 .Dt MENU.4TH 8
 .Os
 .Sh NAME
@@ -69,9 +69,13 @@ Clears the screen area within the menu bounding box.
 Calls
 .Ic menu-erase
 and then redraws the menu.
+.It Ic menu-unset
+Unsets the environment variables associated with individual menu items,
+clearing the way for a new menu.
 .It Ic menu-clear
-Unsets all possible environment variables used
-to configure the menu and then calls
+Calls
+.Ic menu-unset
+and then
 .Ic menu-erase .
 .El
 .Pp