rehearsal marks and the vertical axis of bar lines

[Werner LEMBERG]

[lilypond 2.11.20]

Looking into bar-line.cc, it seems to me that the vertical axis of bar
lines is constructed to properly align them at the beginning of a
staff.  Well, it's not of big importance for Joe User to know the
details -- it works, and this is just fine (some comments in function
Bar_line::compound_barline would be helpful, though).

The very problem, however, is the interaction with rehearsal marks.
As can be seen in the image in section 6.4.5, `Bar lines', the
horizontal alignment of the strings over the various bar line types
(these strings should all be centered horizontally) is, erhm,
surprising.

IMHO we need an `anchor' for objects attached to bar lines which is
the visual middle of the bar line glyphs, not the logical one.

If you agree with my analysis I'll add this to the bug database.


    Werner