Set page breaking properties in the System grob (issue 581470047 by address@hidden)

[nine . fierce . ballads]

What's the purpose of this change?  Is it preparation for a new feature?


https://codereview.appspot.com/581470047/diff/565490043/lily/page-breaking.cc
File lily/page-breaking.cc (right):

https://codereview.appspot.com/581470047/diff/565490043/lily/page-breaking.cc#newcode624
lily/page-breaking.cc:624: for (SCM l = lines; scm_is_pair (l); l =
scm_cdr (l))
Veto! I've had more than one bad experience with lowercase ell.

In one case--I think it was elsewhere in LilyPond--it was purely a
readability issue, but reason enough to avoid it.

In the other, one person *thought* that he was using it as a loop
variable (i, j, k, l, ...), though he was actually using it outside its
loop.  His code compiled anyway because another person had defined a
global of the same name.  Thankfully, I don't work at that company
anymore.

I suggest "SCM line = lines;" as an alternative.

https://codereview.appspot.com/581470047/