Do not project when there are unconstrained impl params

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/ui/traits/unconstrained-projection-normalization-2.rs b/tests/ui/traits/unconstrained-projection-normalization-2.rs
new file mode 100644
index 00000000000..085e9e4a61a
--- /dev/null
+++ b/tests/ui/traits/unconstrained-projection-normalization-2.rs
@@ -0,0 +1,17 @@
+// Make sure we don't ICE in `normalize_erasing_regions` when normalizing
+// an associated type in an impl with unconstrained non-lifetime params.
+// (This time in a function signature)
+
+struct Thing;
+
+pub trait Every {
+    type Assoc;
+}
+impl<T: ?Sized> Every for Thing {
+//~^ ERROR the type parameter `T` is not constrained
+    type Assoc = T;
+}
+
+fn foo(_: <Thing as Every>::Assoc) {}
+
+fn main() {}