"Wrong type" with polyphony, manual beams, dotted rests and notes

[Marcus Macauley]

This one is weird. Apparently some combinations of polyphony, manual
beams, and a dotted rest followed by a note, trigger a "Wrong type"
error (Windows XP here). Many variations I've tried still trigger the
error, while other variations don't. You can experiment for yourself.

Unlike the stemlets-over-rests-only bug which I submitted yesterday,
this one actually interferes with real-world usage.

The complete error message in context is:

"Preprocessing graphical objects...ERROR: Wrong type (expecting real
number): #<unknown-type (0x27 . 0x13c9e48) @ 0x35bbb80>"

Marcus


% The following results in an "ERROR: Wrong type (expecting real number)"
% even if the beamed rest is lengthened or shortened (as long as it's dotted)
% even if the beamed note is lengthened or shortened
% even if (certain) rests are inserted between, before, or after those two.
% The manual beaming and the polyphony both appear to be necessary.
\version "2.10.33"
\paper{ ragged-right=##t }
{ <<
{ r8.[ b16] } \\ % originally: r8[ r16. r32 r8 r16 r16 b8 r32 r16. r8]
{ r4 } >> } % originally: r4 r r r