Re: tests: work around Tru64 sh -e issues for instspc*.test.

[Ralf Wildenhues]

* Eric Blake wrote on Sat, Jan 22, 2011 at 02:41:39PM CET:
> On 01/22/2011 01:30 AM, Ralf Wildenhues wrote:
> >  @prindex @command{unset}
> > -In some nonconforming shells (e.g., Bash 2.05a), @code{unset FOO} fails
> > -when @code{FOO} is not set.  You can use
> > +In some nonconforming shells (e.g., NetBSD 5.99.43 sh or Bash 2.05a),
> > address@hidden FOO} fails when @code{FOO} is not set.  You can use
> 
> Maybe add one additional sentence:
> 
> This can interfere with @code{set -e} operation.

Good idea.  I also added @noindent before the half-sentence after the
example.

> Looks fine with that addition.

Thanks, pushed as below,
Ralf

    docs: update entry about unset.
    
    * doc/autoconf.texi (Limitations of Builtins): NetBSD sh unset
    also fails upon `unset' of a variable that is not set.  Bash 2.01
    could also dump core over `unset MAILPATH'.
    Suggestion by Eric Blake.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 4cb3a8c..7eccba7 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -17758,13 +17758,15 @@ Limitations of Builtins
 @item @command{unset}
 @c ------------------
 @prindex @command{unset}
-In some nonconforming shells (e.g., Bash 2.05a), @code{unset FOO} fails
-when @code{FOO} is not set.  You can use
+In some nonconforming shells (e.g., NetBSD 5.99.43 sh or Bash 2.05a),
address@hidden FOO} fails when @code{FOO} is not set.  This can interfere
+with @code{set -e} operation.  You can use
 
 @smallexample
 FOO=; unset FOO
 @end smallexample
 
address@hidden
 if you are not sure that @code{FOO} is set.
 
 A few ancient shells lack @command{unset} entirely.  For some variables
@@ -17777,8 +17779,8 @@ Limitations of Builtins
 Usually, shells that do not support @command{unset} need less effort to
 make the environment sane, so for example is not a problem if you cannot
 unset @command{CDPATH} on those shells.  However, Bash 2.01 mishandles
address@hidden MAIL} in some cases and dumps core.  So, you should do
-something like
address@hidden MAIL} and @code{unset MAILPATH} in some cases and dumps core.
+So, you should do something like
 
 @smallexample
 ( (unset MAIL) || exit 1) >/dev/null 2>&1 && unset MAIL || :