CVS commit: src/bin/sh

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Mon Nov 26 13:47:39 UTC 2018

Modified Files:
        src/bin/sh: eval.c

Log Message:
Make it be that an empty command is treated as a regular builtin
for the purposes of any redirects it might have -- ie: as posix
requires, make the redirects appear to have been executed in a subshell
environment, so if one fails, aside from a diagnositc msg, all the
running script sees is a command that failed ($? != 0), rather
that having the shell exit which used to happen (the empty command was
being treated as a special builtin).

Continue to treat the empty command as special for the purposes of
var assigns it might contain (those are not executed in a sub-shell
and persist) - an error there (eg: assigning to a readonly var) will
continue to cause the shell (non-interactive shell) to exit.

This makes the NetBSD shell behave like all other (reasonably modern)
shells - fix method (not the implementation, details differ) taken from
FreeBSD who fixed this back in early 2010.    Problem pointed out
in (non-list) mail by Martijn Dekker.


To generate a diff of this commit:
cvs rdiff -u -r1.163 -r1.164 src/bin/sh/eval.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.