1 files changed, 48 insertions, 0 deletions
diff --git a/tests/ui/nll/closure-requirements/propagate-from-trait-match.rs b/tests/ui/nll/closure-requirements/propagate-from-trait-match.rs
new file mode 100644
index 000000000..cda781d8e
--- /dev/null
+++ b/tests/ui/nll/closure-requirements/propagate-from-trait-match.rs
@@ -0,0 +1,48 @@
+// Test that regions which appear only in the closure's generics (in
+// this case, `'a`) are properly mapped to the creator's generics. In
+// this case, the closure constrains its type parameter `T` to outlive
+// the same `'a` for which it implements `Trait`, which can only be the `'a`
+// from the function definition.
+
+// compile-flags:-Zverbose
+
+#![feature(rustc_attrs)]
+#![allow(dead_code)]
+
+trait Trait<'a> {}
+
+fn establish_relationships<T, F>(value: T, closure: F)
+where
+    F: FnOnce(T),
+{
+    closure(value)
+}
+
+fn require<'a, T>(t: T)
+where
+    T: Trait<'a> + 'a,
+{
+}
+
+#[rustc_regions]
+fn supply<'a, T>(value: T)
+where
+    T: Trait<'a>,
+{
+    establish_relationships(value, |value| {
+        // This function call requires that
+        //
+        // (a) T: Trait<'a>
+        //
+        // and
+        //
+        // (b) T: 'a
+        //
+        // The latter does not hold.
+
+        require(value);
+        //~^ ERROR the parameter type `T` may not live long enough
+    });
+}
+
+fn main() {}