3 files changed, 58 insertions, 0 deletions
diff --git a/tests/ui/traits/new-solver/assembly/assemble-normalizing-self-ty-impl-ambiguity.rs b/tests/ui/traits/new-solver/assembly/assemble-normalizing-self-ty-impl-ambiguity.rs
new file mode 100644
index 00000000000..826e8c1e0b1
--- /dev/null
+++ b/tests/ui/traits/new-solver/assembly/assemble-normalizing-self-ty-impl-ambiguity.rs
@@ -0,0 +1,27 @@
+// compile-flags: -Ztrait-solver=next
+// check-pass
+
+// Checks that we do not get ambiguity by considering an impl
+// multiple times if we're able to normalize the self type.
+
+trait Trait<'a> {}
+
+impl<'a, T: 'a> Trait<'a> for T {}
+
+fn impls_trait<'a, T: Trait<'a>>() {}
+
+trait Id {
+    type Assoc;
+}
+impl<T> Id for T {
+    type Assoc = T;
+}
+
+fn call<T>() {
+    impls_trait::<<T as Id>::Assoc>();
+}
+
+fn main() {
+    call::<()>();
+    impls_trait::<<<() as Id>::Assoc as Id>::Assoc>();
+}
diff --git a/tests/ui/traits/new-solver/dont-normalize-proj-with-error.rs b/tests/ui/traits/new-solver/dont-normalize-proj-with-error.rs
new file mode 100644
index 00000000000..19a6fa990ff
--- /dev/null
+++ b/tests/ui/traits/new-solver/dont-normalize-proj-with-error.rs
@@ -0,0 +1,22 @@
+// compile-flags: -Ztrait-solver=next
+
+// Test that we don't incorrectly leak unconstrained inference variables
+// if the projection contained an error. This caused an ICE in writeback.
+
+trait Mirror {
+    type Assoc: ?Sized;
+}
+
+struct Wrapper<T: ?Sized>(T);
+impl<T: ?Sized> Mirror for Wrapper<T> {
+    type Assoc = T;
+}
+
+fn mirror<W: Mirror>(_: W) -> Box<W::Assoc> { todo!() }
+
+fn type_error() -> TypeError { todo!() }
+//~^ ERROR cannot find type `TypeError` in this scope
+
+fn main() {
+    let x = mirror(type_error());
+}
diff --git a/tests/ui/traits/new-solver/dont-normalize-proj-with-error.stderr b/tests/ui/traits/new-solver/dont-normalize-proj-with-error.stderr
new file mode 100644
index 00000000000..5a7459ec1fd
--- /dev/null
+++ b/tests/ui/traits/new-solver/dont-normalize-proj-with-error.stderr
@@ -0,0 +1,9 @@
+error[E0412]: cannot find type `TypeError` in this scope
+  --> $DIR/dont-normalize-proj-with-error.rs:17:20
+   |
+LL | fn type_error() -> TypeError { todo!() }
+   |                    ^^^^^^^^^ not found in this scope
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0412`.