Fix a bug in type class enrichment from substructures

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/mproj.ur b/tests/mproj.ur
new file mode 100644
index 00000000..8e4317c7
--- /dev/null
+++ b/tests/mproj.ur
@@ -0,0 +1,21 @@
+structure M : sig
+    type t
+    val x : t
+
+    structure S : sig
+        type u = t
+
+        val eq : eq u
+    end
+end = struct
+    type t = int
+    val x = 0
+
+    structure S = struct
+        type u = t
+
+        val eq = _
+    end
+end
+
+val y = M.x = M.x