On Fri, 5 Jul 2019, Artur Tarassow wrote:
 Am 05.07.19 um 14:04 schrieb Sven Schreiber:
> 
> 2) Simply be more explicit by adding "list" at the start:
> 
> list b.L += FOO*
> 
 Thanks, Sven. I like the latter solution which works well. 
That's certainly the recommended version. However, we now (git) make 
an effort to detect a bundled list on the LHS of a modified 
assignment at the preprocessing stage, so plain "b.L += FOO*" will 
now work (though not in any release).
Allin