Add regtest for \contextStringTuning.

Somebody might want to make a better test / better texidoc, but at
the moment I just want to have something in there.  This function
was not previously tested.

diff --git a/input/regression/context-string-tuning.ly b/input/regression/context-string-tuning.ly
new file mode 100644 (file)
index 0000000..2281bb9
--- /dev/null
+++ b/input/regression/context-string-tuning.ly
@@ -0,0 +1,24 @@
+\version "2.14.0"
+
+\header {
+  texidoc="
+Using \contextStringTuning does not break compiling.
+"
+}
+
+mynotes = {
+  c'4 e' g' c'' |
+  e''4 g'' b'' c'''
+}
+
+<<
+  \new Staff {
+    \clef treble
+    \mynotes
+  }
+  \new TabStaff {
+    \contextStringTuning #'custom-tuning <c' g' d'' a''>
+    \mynotes
+  }
+>>
+