Reference:
 <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=7800>

On Friday 07 January 2011, Ralf Wildenhues wrote:
> Hi Stefano,
> 
> thanks for the report.
> 
> * Stefano Lattarini wrote on Fri, Jan 07, 2011 at 03:36:43PM CET:
> > Currently, automake is not smart enough to resolve variable expansions
> > in AM_YFLAGS (or foo_YFLAGS) when scanning them for the `-d' flag.
> 
> value_as_list_recursive can usually help here.
> 
> > Not sure if this bug is worth fixing, but having it reported in the bug
> > database won't hurt, either (and I might anyway attempt a fix soonish).
> 
> The usual complication is what to do if
> - the variable is overridden at 'make' time (automake usually punts in
>   that case),
> - the variable is conditionally set (this usually requires making the
>   automake code more complex to solve).
> 
> Punting also for the latter is fine if the feature is expected to be
> little-used.
> 
> Cheers,
> Ralf
> 

The attached two-patch series should fix the bug (the first patch
is a testsuite enhancement, the second one really fixes the bug).

OK to apply to the temporary branch 'yacc-clean' (recently merged into
master with commit v1.11-575-ga297a16) and merge to master again?

Regards,
   Stefano