1 files changed, 37 insertions, 0 deletions
diff --git a/src/test/ui/span/issue-24805-dropck-child-has-items-via-parent.rs b/src/test/ui/span/issue-24805-dropck-child-has-items-via-parent.rs
new file mode 100644
index 000000000..9c772052f
--- /dev/null
+++ b/src/test/ui/span/issue-24805-dropck-child-has-items-via-parent.rs
@@ -0,0 +1,37 @@
+// Check that child trait who only has items via its *parent* trait
+// does cause dropck to inject extra region constraints.
+
+#![allow(non_camel_case_types)]
+
+trait Parent { fn foo(&self); }
+trait Child: Parent { }
+
+impl Parent for i32 { fn foo(&self) { } }
+impl<'a> Parent for &'a D_Child<i32> {
+    fn foo(&self) {
+        println!("accessing child value: {}", self.0);
+    }
+}
+
+impl Child for i32 { }
+impl<'a> Child for &'a D_Child<i32> { }
+
+struct D_Child<T:Child>(T);
+impl <T:Child> Drop for D_Child<T> { fn drop(&mut self) { self.0.foo() } }
+
+fn f_child() {
+    // `_d` and `d1` are assigned the *same* lifetime by region inference ...
+    let (_d, d1);
+
+    d1 = D_Child(1);
+    // ... we store a reference to `d1` within `_d` ...
+    _d = D_Child(&d1);
+    //~^ ERROR `d1` does not live long enough
+
+    // ... dropck *should* complain, because Drop of _d could (and
+    // does) access the already dropped `d1` via the `foo` method.
+}
+
+fn main() {
+    f_child();
+}