1 files changed, 59 insertions, 0 deletions
diff --git a/tests/ui/impl-trait/in-trait/rpitit-duplicate-associated-fn-with-nested.rs b/tests/ui/impl-trait/in-trait/rpitit-duplicate-associated-fn-with-nested.rs
new file mode 100644
index 00000000000..9c9cef24a96
--- /dev/null
+++ b/tests/ui/impl-trait/in-trait/rpitit-duplicate-associated-fn-with-nested.rs
@@ -0,0 +1,59 @@
+// issue#143560
+
+trait T {
+    type Target;
+}
+
+trait Foo {
+    fn foo() -> impl T<Target = impl T<Target = impl Sized>>;
+    fn foo() -> impl Sized;
+    //~^ ERROR: the name `foo` is defined multiple times
+}
+
+trait Bar {
+    fn foo() -> impl T<Target = impl T<Target = impl Sized>>;
+    fn foo() -> impl T<Target = impl T<Target = impl Sized>>;
+    //~^ ERROR: the name `foo` is defined multiple times
+}
+
+struct S<T> {
+    a: T
+}
+
+trait Baz {
+    fn foo() -> S<impl T<Target = S<S<impl Sized>>>>;
+    fn foo() -> S<impl T<Target = S<S<impl Sized>>>>;
+    //~^ ERROR: the name `foo` is defined multiple times
+}
+
+struct S1<T1, T2> {
+    a: T1,
+    b: T2
+}
+
+trait Qux {
+    fn foo() -> S1<
+        impl T<Target = impl T<Target = impl Sized>>,
+        impl T<Target = impl T<Target = S<impl Sized>>>
+        >;
+    fn foo() -> S1<
+        impl T<Target = impl T<Target = impl Sized>>,
+        impl T<Target = impl T<Target = S<impl Sized>>>
+        >;
+    //~^^^^ ERROR: the name `foo` is defined multiple times
+}
+
+trait T0<T> {
+    type Target;
+}
+trait T1<T> {}
+
+trait X {
+    fn a() -> impl T0<(), Target = impl T1<()>>;
+    fn a() -> impl T0<(), Target = impl T1<()>>;
+    //~^ ERROR the name `a` is defined multiple times
+    fn a() -> impl T0<(), Target = impl T1<()>>;
+    //~^ ERROR the name `a` is defined multiple times
+}
+
+fn main() {}