bin/40256: sh bug breaks etcupdate

[Christoph_Egger%gmx.de@localhost]

>Number:         40256
>Category:       bin
>Synopsis:       sh bug breaks etcupdate
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Dec 22 23:25:00 +0000 2008
>Originator:     Christoph Egger
>Release:        5.99.5
>Organization:
>Environment:
NetBSD netbsdamd64 5.99.5 NetBSD 5.99.5 (GENERIC) #75: Sun Dec 14 09:03:02 CET 
2008  
cegger%powermacg5.local@localhost:/Users/cegger/devel/bsd/netbsd/src-xen/build/obj.kern.amd64/GENERIC
 amd64
>Description:
In -current, latest sh changes introduced a new bug
which breaks etcupdate -s etc.tgz
>How-To-Repeat:

A little shell script triggers the sh bug.

Script1.sh:
---------------------------
#!/bin/sh

TEMPROOT="${TEMPROOT:=/tmp/temproot}"
mkdir -p "${TEMPROOT}"
---------------------------

Script2.sh:
---------------------------
TEMPROOT="/tmp/temproot"
mkdir -p "${TEMPROOT}"
---------------------------

Script1.sh creates a ./?/tmp?/temproot
directory hierarchy.

Script2.sh creates a /tmp/temproot
directory hierarchy.


>Fix: