bin/52172: /bin/ksh crashes on re-executing an alias that adds environment

[nis7999%gmail.com@localhost]

>Number:         52172
>Category:       bin
>Synopsis:       /bin/ksh crashes on re-executing an alias that adds environment
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 17 11:40:00 +0000 2017
>Originator:     Shingo Nishioka
>Release:        NetBSD 7.1_STABLE
>Organization:
>Environment:
amd64
>Description:
As alias expansion stops if command is alias word itself,
an alias can be used to add environment variable to a simple command.
Re-execute such alias causes /bin/ksh to crash.

workaround: 
add trailing space to aliased command. 
For example:
alias ls='LANG=C ls '

Other implementation:
bash, mksh, ksh93, and zsh are not affected this problem.

>How-To-Repeat:
$ /bin/ksh
$ alias ls='LANG=C ls'
$ ls
$ fc -e -

>Fix: