From 8dfb8cb1d1c7cdb47635ec49b7103194a447e2f9 Mon Sep 17 00:00:00 2001
From: Paul Morris <paulwmorris@gmail.com>
Date: Wed, 6 Jan 2016 16:29:46 -0500
Subject: [PATCH] Do not draw ledger lines on top of staff lines

when StaffSymbol.ledger-extra > 0
---
 input/regression/ledger-extra.ly | 28 ++++++++++++++++++++++++++++
 lily/staff-symbol.cc             | 15 ++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 input/regression/ledger-extra.ly

diff --git a/input/regression/ledger-extra.ly b/input/regression/ledger-extra.ly
new file mode 100644
index 0000000000..55ad653ef6
--- /dev/null
+++ b/input/regression/ledger-extra.ly
@@ -0,0 +1,28 @@
+\version "2.19.36"
+
+\header {
+  texidoc = "The ledger-extra grob property increases
+the number of ledger lines drawn, but they are not
+drawn on top of staff lines."
+}
+
+notes = \relative {
+  \time 6/8
+  a4. b | c d | e f |
+  g4. a | b c | d e |
+  f4. g | a b |
+}
+
+\new Staff {
+  \notes
+}
+
+\new Staff {
+  \override Staff.StaffSymbol.ledger-extra = 1
+  \notes
+}
+
+\new Staff {
+  \override Staff.StaffSymbol.ledger-extra = 2
+  \notes
+}
diff --git a/lily/staff-symbol.cc b/lily/staff-symbol.cc
index de88102d14..256a9bdd0d 100644
--- a/lily/staff-symbol.cc
+++ b/lily/staff-symbol.cc
@@ -247,7 +247,20 @@ Staff_symbol::ledger_positions (Grob *me, int pos)
           values[i] = nearest_line + dir * (ledger_count - i) * 2;
         }
     }
-  return values;
+  // remove any ledger lines that would fall on staff lines,
+  // which can happen when ledger-extra > 0
+  vector<Real> final_values;
+  for (vector<Real>::const_iterator i = values.begin (),
+       e = values.end ();
+       i != e;
+       ++i)
+    {
+      if (find (line_positions.begin (), line_positions.end (), *i) == line_positions.end ())
+        {
+          final_values.push_back (*i);
+        }
+    }
+  return final_values;
 }
 
 int
-- 
2.39.2