Thanks Jean, both for the solution and for the education.
> On 21 May 2023, at 13:58, Jean Abou Samra <j...@abou-samra.fr> wrote:
>
>
>>
>> Le dimanche 21 mai 2023 à 12:09 +0100, Graham King a écrit :
>>
>> In the following code, I would expect the tie between the final two notes to
>> be dotted. The actual output is a solid tie. Not sure whether this is a
>> bug or just my doing something wrong...
>>
>> \version "2.25.0"
>>
>> { c''2
>> \once \tieDotted
>> \set melismaBusyProperties = #'()
>> 1 ~ 2
>> }
>>
>> \layout {
>> \context {
>> \Voice
>> \remove "Note_heads_engraver"
>> \consists "Completion_heads_engraver"
>> }
>> }
>> I can work around this pretty easily, but I'd rather preserve the note
>> durations of the original mensural notation if possible.
>>
> That the second tie is not dotted is perfectly normal since \once makes a
> command apply only at the current moment, and that tie starts later.
>
I feared that this might be the case. I'll have to be much more circumspect
when using the Completion_heads_engraver, in case a change of barline
distribution triggers this unexpectedly.
> What is more surprising is that the first tie is not dotted; this is harder
> to explain simply, it's caused by shenanigans in the internals of
> Completion_heads_engrver (it creates ties “retroactively”, later than when
> they start).
>
> Try
>
> \version "2.24.1"
>
> { c''2
> \once \override Tie.color = red
> \set melismaBusyProperties = #'()
> 1 \single \tieDotted ~ 2
> }
>
> \layout {
> \context {
> \Voice
> \remove "Note_heads_engraver"
> \consists "Completion_heads_engraver"
> }
> }
That works! I didn't know about \single (and I hadn't thought of using a
tweak). I might convert all my dotted-tie instances to this mechanism, to
avoid the impression that the decisions of the Completion_heads_engraver are
changing the semantics of the .ly file.
