From: David Kastrup <dak@gnu.org>
Date: Thu, 23 May 2013 20:03:10 +0000 (+0200)
Subject: Issue 3375: Fix accounting problem in page breaking
X-Git-Tag: release/2.17.19-1~8^2~1
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=dcace4c82a3d5dfa679a3331128c98febbec925c;p=lilypond.git

Issue 3375: Fix accounting problem in page breaking

The code

\markup \stencil #(ly:make-stencil '() empty-interval empty-interval)
\markup *
\markup *
\markup *
\markup *

distributed itself across 5 pages because page accounting was thrown
off by empty intervals.  While the effects were smaller (and did not
propagate to the next page) with the less radically empty intervals
employed as extents of empty-stencil, they were still present.
---

diff --git a/lily/constrained-breaking.cc b/lily/constrained-breaking.cc
index ee8b28906c..8d3b6967e4 100644
--- a/lily/constrained-breaking.cc
+++ b/lily/constrained-breaking.cc
@@ -571,7 +571,9 @@ Line_details::Line_details (Prob *pb, Output_def *paper)
 
   last_column_ = 0;
   force_ = 0;
-  Interval stencil_extent = unsmob_stencil (pb->get_property ("stencil"))->extent (Y_AXIS);
+  Stencil *st = unsmob_stencil (pb->get_property ("stencil"));
+  Interval stencil_extent = st->is_empty () ? Interval (0, 0)
+    : st->extent (Y_AXIS);
   shape_ = Line_shape (stencil_extent, stencil_extent); // pretend it goes all the way across
   tallness_ = 0;
   bottom_padding_ = 0;