shell parsing bug with &>

[Rich Felker]

On Mon, Sep 03, 2012 at 12:58:37PM +0200, Denys Vlasenko wrote:
> On Sun, Sep 2, 2012 at 11:21 PM, Rich Felker <dalias at aerifal.cx> wrote:
> > It seems busybox ash is misinterpreting "&>" as having some special
> > meaning rather than being a "&" token followed by a ">" token. I've
> > filed a bug report:
> >
> > https://bugs.busybox.net/show_bug.cgi?id=5498
> 
> Set CONFIG_ASH_BASH_COMPAT to "no" and it will stop doing that.

Indeed I tested and this fixes the problem. But all the other reasons
to turn CONFIG_ASH_BASH_COMPAT off just seem to be minimizing binary
size; I couldn't find any other extensions that conflict the
interpreting of standards-conforming shell programs.

To resolve this issue, I'd really like to see either the option split
out into harmless bash extensions vs incompatible bash extensions, or
just a note added to the documentation in configure that
CONFIG_ASH_BASH_COMPAT can break the parsing of conforming scripts
(rather than just adding extensions that won't break anything).

Rich