1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/specialization/assoc-ty-graph-cycle.rs b/src/test/ui/specialization/assoc-ty-graph-cycle.rs
new file mode 100644
index 000000000..fc39b553a
--- /dev/null
+++ b/src/test/ui/specialization/assoc-ty-graph-cycle.rs
@@ -0,0 +1,25 @@
+// run-pass
+
+// Make sure we don't crash with a cycle error during coherence.
+
+#![feature(specialization)] //~ WARN the feature `specialization` is incomplete
+
+trait Trait<T> {
+    type Assoc;
+}
+
+impl<T> Trait<T> for Vec<T> {
+    default type Assoc = ();
+}
+
+impl Trait<u8> for Vec<u8> {
+    type Assoc = u8;
+}
+
+impl<T> Trait<T> for String {
+    type Assoc = ();
+}
+
+impl Trait<<Vec<u8> as Trait<u8>>::Assoc> for String {}
+
+fn main() {}