Oddity with \( indentation in LilyPond-mode

[Reuben Thomas]

Something I don't really understand: although the only indent setting I
have that is non-zero is LilyPond-indent, when I have a construct like

          c2\( \cresc b4 a \endcresc a( gs8 fs gs2) |
               a1\) r1 |

LilyPond-mode insists on indenting it as shown. If I remove the \( on the
first line, the second line is unindented.

If I do something similar but with ( instead of \(, the indentation is
also correct (i.e. no extra indent on the second line).

There's a comment in lilypond-indent.el at one point saying

          ;; expressional slurs  '\( ... \)' are not taken into account

which could be something to do with it, and there seems to be special case
code for expression slurs at several points, but my head hurts after
staring at all the \\, so I'm not sure.

-- 
http://www.mupsych.org/~rrt/
author, n.  one who parades ignorance in public