X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=input%2Fregression%2Fautomatic-polyphony-context-id.ly;fp=input%2Fregression%2Fautomatic-polyphony-context-id.ly;h=a825222600af6f05eff90558de556b2e73de96a8;hb=941dff9d2a67080e0dd8474f1e70f0c72ace6424;hp=0000000000000000000000000000000000000000;hpb=5a22d6233a39d3164e1ca043244794c268be4ad0;p=lilypond.git

diff --git a/input/regression/automatic-polyphony-context-id.ly b/input/regression/automatic-polyphony-context-id.ly
new file mode 100644
index 0000000000..a825222600
--- /dev/null
+++ b/input/regression/automatic-polyphony-context-id.ly
@@ -0,0 +1,36 @@
+\version "2.14.0"
+
+\header {
+  texidoc = "The bottom-level contexts in polyphony shorthand are
+allocated a context id in order of creation, starting with
+@code{\"1\"}.
+This snippet will fail to compile if either voice has an invalid
+@code{context-id} string.
+"
+}
+
+assertContextId =
+#(define-music-function (parser location id) (string?)
+   (let ((music (make-music 'ApplyContext
+                            'procedure
+                            (lambda (ctx)
+                              (and
+                               (not (string=? (ly:context-id ctx) id))
+                               (ly:error "context-id mismatch found: expecting ~s, got ~s"
+                                         id
+                                         (ly:context-id ctx)))))))
+     music))
+
+\relative c'' {
+  <<
+    {
+      \assertContextId "1"
+      c4 d e2
+    }
+    \\
+    {
+      \assertContextId "2"
+      a,4 b c2
+    }
+  >>
+}