Add regression test for issue 879

diff --git a/input/regression/remove-empty-staves-auto-knee.ly b/input/regression/remove-empty-staves-auto-knee.ly
new file mode 100644 (file)
index 0000000..e86ce39
--- /dev/null
+++ b/input/regression/remove-empty-staves-auto-knee.ly
@@ -0,0 +1,48 @@
+\version "2.13.46"\r
+\r
+\header {\r
+  texidoc = "\r
+RemoveEmptyStaves should keep the pre-existing value of\r
+@code{auto-knee-gap}.  In this case, the cross-staff beam\r
+should be between the two staves.\r
+"\r
+}\r
+\r
+staffMusic = \new StaffGroup {\r
+  <<\r
+    \new Staff = "rh" {\r
+      \relative c' {\r
+        c1 \break\r
+        c1 \break\r
+        c8[ c c c\r
+        \change Staff = "lh"\r
+        g, g g g]\r
+        \change Staff = "rh"\r
+       c1\r
+      }\r
+    }\r
+    \new Staff = "lh" {\r
+      \relative c {\r
+        \clef bass\r
+        c1\r
+        R1\r
+        R1\r
+       R1\r
+      }\r
+    }\r
+  >>\r
+}\r
+\r
+\score {\r
+  \staffMusic\r
+}\r
+\r
+\layout {\r
+  ragged-right = ##t\r
+  \context {\r
+    \Staff\r
+    \override Beam #'auto-knee-gap = #4.5\r
+    \RemoveEmptyStaves\r
+  }\r
+}\r
+\r