ksh incompatabilities with sh?

[Dennis L. Mumaugh]

In article <4627 at hoptoad.uucp> gnu at hoptoad.uucp (John Gilmore) writes:
   I have heard this too, over the years, and would like real
   documentation on what's wrong.  Are there gross bugs in "sh" that ksh
   is too polite to perpetuate, but which users depend upon?  It would
   seem the best course to fix the ksh to match the sh in all respects,
   rename it to /bin/sh, and throw away the old sh.  I thought that was
   the original idea; what happened?

I have seen a couple:

1) the test builtin for sh accepts extra arguments:
	test -r /bin/*
while the ksh test builtin complains about syntax error


2) Also, several environment variables are set  readonly  in  ksh
but  not  in  sh and when cron/at is setting up an at job it will
attempt to re-establish  the  user's  enviornment  and  sets  the
"read-only" variables.
-- 
=Dennis L. Mumaugh
 Lisle, IL       ...!{ihnp4,cbosgd,lll-crg}!cuuxb!dlm