Gets first stem-info of a kneed-beam right (issue 5043047)

[mtsolo]

Reviewers: ,

Message:
Hey all,

Cleaning up my work on broken beam slopes, I found this bug in
calc_stem_info.  It is a one liner, but it has a pretty significant
impact on kneed beams.  The first stem info of all kneed beams is
currently being incorrectly calculated because it accessed the property
directly instead of using Beam::is_knee.  This fixes that problem.

I'd like to push it directly to current master, as it is a one liner,
passes regtests (it changes several files that were incorrect before),
and I can't move on with my work on the other patch until this is sorted
out.  I'm gonna hold off until I get some responses back, though, to
make sure that people are cool with this.

Cheers,
MS

Description:
Gets first stem-info of a kneed-beam right

Please review this at http://codereview.appspot.com/5043047/

Affected files:
  M lily/stem.cc


Index: lily/stem.cc
diff --git a/lily/stem.cc b/lily/stem.cc
index  
6575914789de9e84c7e9164592d82eda600b6319..f6bedcfd95461992e1e2498b34b055c8e1c0a0fb  
100644
--- a/lily/stem.cc
+++ b/lily/stem.cc
@@ -988,7 +988,7 @@ Stem::calc_stem_info (SCM smob)

   Also, not for knees.  Seems to be a good thing. */
   bool no_extend = to_boolean (me->get_property ("no-stem-extend"));
-  bool is_knee = to_boolean (beam->get_property ("knee"));
+  bool is_knee = Beam::is_knee (beam);
   if (!no_extend && !is_knee)
     {
       /* Highest beam of (UP) beam must never be lower than middle