''"$@" expansion

On Sun, May 1, 2016 at 7:29 PM, Chet Ramey <chet.ramey@case.edu> wrote:

Thanks for the report. This was discussed by the austin group back in 2014
and resulted in Posix interpretation 888.

Thanks for the pointer. Looking at that interpretation (http://austingroupbugs.net/view.php?id=888), I noticed that it includes one case that bash is not handling correctly:

If there are no positional parameters, the expansion of @ shall generate zero fields […] however, if the expansion is embedded within a word which contains one or more other parts that expand to a quoted null string, these null string(s) shall still produce an empty field […]

The provided example is:

set --
printf '[%s]\n' foo ''"$@"
[foo]
[]

(Bash just prints [foo]).

The attached exp9.sub and exp.right could be used for testing all the examples from the interpretation if desired. I removed the test cases that included undefined behavior.

From:	Grisha Levit
Subject:	''"$@" expansion
Date:	Thu, 12 May 2016 19:37:45 -0400