Timing of events in the beginning of bars

[Erik Sandberg]

Hi,

If something happens in the beginning of a bar, such as a clef change, a 
\mark, or a time signature, then this is currently placed at time 0, which is 
_after_ any grace notes. This results, as Julien pointed out, in problems in 
cases such as this:
<<
    \context Staff=A {r1 | \mark "X" c8}
    \context Staff=B {r1 | \grace c8 c}
>>

In my opinion, what the user would expect, is that the mark should be placed 
in the beginning of that bar. However, the mark is added _after_ the grace 
note.

I have been thinking some more about it. I realised that intuitively, \mark 
should be considered placed after the note preceding it, as opposed to before 
the note following it. Which AFAICS would be equivalent to subtracting 
infinity to the grace part of its time stamp, whenever there is no grace note 
preceding the \mark in the current context.

This semantics would not destroy anything; you would still be able to add 
marks etc. after grace notes by
<<
    \context Staff=A {r1 | \grace s8 \mark "X" c8}
    \context Staff=B {r1 | \grace c8 c}
>>
(which is actually a bit dirty, but would very rarely be needed)

Does this sound sensible to you developers? If it does I'll add it to the bug 
cvs as a wish.

Erik