From 782824c48f79d5fbe6732484e4b5cc4ab9892e41 Mon Sep 17 00:00:00 2001
From: Yerkebulan Tulibergenov <yerkebulan@gmail.com>
Date: Tue, 15 Jun 2021 21:32:13 -0700
Subject: [PATCH] add regression test for issue #78632

---
 src/test/ui/traits/issue-78632.rs | 59 +++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 src/test/ui/traits/issue-78632.rs

diff --git a/src/test/ui/traits/issue-78632.rs b/src/test/ui/traits/issue-78632.rs
new file mode 100644
index 00000000000..c72a2aef490
--- /dev/null
+++ b/src/test/ui/traits/issue-78632.rs
@@ -0,0 +1,59 @@
+// check-pass
+//
+// Regression test for issue #78632
+
+#![crate_type = "lib"]
+
+pub trait Corge<T> {
+    type Fred;
+}
+
+impl Corge<u8> for () {
+    type Fred = u32;
+}
+
+pub trait Waldo {
+    type Quax;
+}
+
+impl Waldo for u32 {
+    type Quax = u8;
+}
+
+pub trait Grault
+where
+    (): Corge<Self::Thud>,
+{
+    type Thud;
+    fn bar(_: <() as Corge<Self::Thud>>::Fred) {}
+}
+
+impl<T> Grault for T
+where
+    T: Waldo,
+    (): Corge<T::Quax>,
+    <() as Corge<T::Quax>>::Fred: Waldo,
+{
+    type Thud = u8;
+}
+
+pub trait Plugh<I> {
+    fn baz();
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct Qiz<T> {
+    foo: T,
+}
+
+impl<T> Plugh<<() as Corge<T::Thud>>::Fred> for Qiz<T>
+where
+    T: Grault,
+    (): Corge<T::Thud>,
+{
+    fn baz() {}
+}
+
+pub fn test() {
+    <Qiz<u32> as Plugh<u32>>::baz();
+}