>> When I attempt to change the "direction" property of a slur,
>> whether that is with \tweak or \override, I cannot set the
>> direction to neutral (0). UP (1) and DOWN (-1) work fine, but when
>> setting to 0, I get the following error:
>>
>> "Assertion failed: d, file
>> /home/lily/lilypond-2.24.0/release/binaries/mingw/lilypond/lilypond-2.24.0/flower/include/drul-array.hh,
>> line 56
>> Exited with return code 3." [...]
>
> You can see with
>
> \void \displayLilyMusic \slurNeutral
>
> that \slurNeutral is not equivalent to \override Slur.direction =
> #0, but \revert Slur.direction, which reverts Slur.direction to its
> default value #ly:slur::calc-direction. [...]
But the user shouldn't see an assertion error even in case of a wrong
argument, right?
Werner
