Merge ref 'f957826bff7a' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: f957826bff7a68b267ce75b1ea56352aed0cca0a
Filtered ref: 7291893f9d875b6e8775a7a0e661abdaec15d3c1
Upstream diff: https://github.com/rust-lang/rust/compare/caccb4d0368bd918ef6668af8e13834d07040417...f957826bff7a68b267ce75b1ea56352aed0cca0a

This merge was created using https://github.com/rust-lang/josh-sync.

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/ui/impl-trait/method/method-resolution4.rs b/tests/ui/impl-trait/method/method-resolution4.rs
new file mode 100644
index 00000000000..f90a9309cda
--- /dev/null
+++ b/tests/ui/impl-trait/method/method-resolution4.rs
@@ -0,0 +1,18 @@
+//! The recursive method call yields the opaque type. The
+//! `next` method call then constrains the hidden type to `&mut _`
+//! because `next` takes `&mut self`. We never resolve the inference
+//! variable, but get a type mismatch when comparing `&mut _` with
+//! `std::iter::Empty`.
+
+//@ revisions: current next
+//@[next] compile-flags: -Znext-solver
+//@ check-pass
+
+fn foo(b: bool) -> impl Iterator<Item = ()> {
+    if b {
+        foo(false).next().unwrap();
+    }
+    std::iter::empty()
+}
+
+fn main() {}