1 files changed, 35 insertions, 0 deletions
diff --git a/tests/ui/regions/regions-trait-object-1.rs b/tests/ui/regions/regions-trait-object-1.rs
new file mode 100644
index 000000000..e2520d978
--- /dev/null
+++ b/tests/ui/regions/regions-trait-object-1.rs
@@ -0,0 +1,35 @@
+// run-pass
+// This is a regression test for something that only came up while
+// attempting to bootstrap librustc_ast; it is adapted from
+// `rustc_ast::ext::tt::generic_extension`.
+
+
+pub struct E<'a> {
+    pub f: &'a u8,
+}
+impl<'b> E<'b> {
+    pub fn m(&self) -> &'b u8 { self.f }
+}
+
+pub struct P<'c> {
+    pub g: &'c u8,
+}
+pub trait M {
+    fn n(&self) -> u8;
+}
+impl<'d> M for P<'d> {
+    fn n(&self) -> u8 { *self.g }
+}
+
+fn extension<'e>(x: &'e E<'e>) -> Box<dyn M+'e> {
+    loop {
+        let p = P { g: x.m() };
+        return Box::new(p) as Box<dyn M+'e>;
+    }
+}
+
+fn main() {
+    let w = E { f: &10 };
+    let o = extension(&w);
+    assert_eq!(o.n(), 10);
+}