Normalize possibly unnormalized type in relate_type_and_user_type

1 files changed, 3 insertions, 0 deletions

diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs
index 4d57e7aac58..3c95ebf9ffa 100644
--- a/compiler/rustc_borrowck/src/type_check/mod.rs
+++ b/compiler/rustc_borrowck/src/type_check/mod.rs
@@ -482,6 +482,9 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         }
         trace!(?curr_projected_ty);
 
+        // Need to renormalize `a` as typecheck may have failed to normalize
+        // higher-ranked aliases if normalization was ambiguous due to inference.
+        let a = self.normalize(a, locations);
         let ty = self.normalize(curr_projected_ty.ty, locations);
         self.relate_types(ty, v.xform(ty::Contravariant), a, locations, category)?;