From 377d8fa4e3057838f20dd1eb1669d4ebaf8a561a Mon Sep 17 00:00:00 2001
From: Boxy <rust@boxyuwu.dev>
Date: Wed, 18 Jun 2025 15:04:03 +0100
Subject: Reviews

---
 compiler/rustc_type_ir/src/fast_reject.rs                           | 3 ---
 tests/ui/associated-inherent-types/bound_vars_in_args.rs            | 4 ++--
 tests/ui/associated-inherent-types/candidate-with-alias-2.rs        | 3 +++
 tests/ui/associated-inherent-types/candidate-with-alias-2.stderr    | 6 +++---
 tests/ui/associated-inherent-types/candidate-with-alias.rs          | 3 +++
 .../associated-inherent-types/multiple-candidates-in-adt-field-2.rs | 4 ++--
 6 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/compiler/rustc_type_ir/src/fast_reject.rs b/compiler/rustc_type_ir/src/fast_reject.rs
index a5d461c57cd..d88c88fc6f3 100644
--- a/compiler/rustc_type_ir/src/fast_reject.rs
+++ b/compiler/rustc_type_ir/src/fast_reject.rs
@@ -241,9 +241,6 @@ impl<I: Interner, const INSTANTIATE_LHS_WITH_INFER: bool, const INSTANTIATE_RHS_
     }
 
     pub fn types_may_unify_with_depth(self, lhs: I::Ty, rhs: I::Ty, depth_limit: usize) -> bool {
-        if lhs == rhs {
-            return true;
-        }
         self.types_may_unify_inner(lhs, rhs, depth_limit)
     }
 
diff --git a/tests/ui/associated-inherent-types/bound_vars_in_args.rs b/tests/ui/associated-inherent-types/bound_vars_in_args.rs
index 0baa242af76..49a9ef31cd6 100644
--- a/tests/ui/associated-inherent-types/bound_vars_in_args.rs
+++ b/tests/ui/associated-inherent-types/bound_vars_in_args.rs
@@ -1,8 +1,8 @@
 #![feature(non_lifetime_binders, inherent_associated_types)]
 #![expect(incomplete_features)]
 
-// Test that we can resolve to the right IAT when the self type
-// contains a bound type.
+// Test whether we can resolve to the right IAT when the self type
+// contains a bound type. This should ideally use the second impl.
 
 struct Foo<T: ?Sized>(T);
 
diff --git a/tests/ui/associated-inherent-types/candidate-with-alias-2.rs b/tests/ui/associated-inherent-types/candidate-with-alias-2.rs
index d7be825a9c2..551d30a8786 100644
--- a/tests/ui/associated-inherent-types/candidate-with-alias-2.rs
+++ b/tests/ui/associated-inherent-types/candidate-with-alias-2.rs
@@ -1,6 +1,9 @@
 #![feature(inherent_associated_types)]
 #![expect(incomplete_features)]
 
+// A behaviour test showcasing that we do not normalize associated types in
+// the impl self ty when assembling IAT candidates
+
 trait Identity {
     type Assoc;
 }
diff --git a/tests/ui/associated-inherent-types/candidate-with-alias-2.stderr b/tests/ui/associated-inherent-types/candidate-with-alias-2.stderr
index 335e35a9577..2b79b65f22b 100644
--- a/tests/ui/associated-inherent-types/candidate-with-alias-2.stderr
+++ b/tests/ui/associated-inherent-types/candidate-with-alias-2.stderr
@@ -1,16 +1,16 @@
 error[E0034]: multiple applicable items in scope
-  --> $DIR/candidate-with-alias-2.rs:20:23
+  --> $DIR/candidate-with-alias-2.rs:23:23
    |
 LL |     field: <Foo<u8>>::Inherent,
    |                       ^^^^^^^^ multiple `Inherent` found
    |
 note: candidate #1 is defined in an impl for the type `Foo<<u8 as Identity>::Assoc>`
-  --> $DIR/candidate-with-alias-2.rs:13:5
+  --> $DIR/candidate-with-alias-2.rs:16:5
    |
 LL |     type Inherent = u8;
    |     ^^^^^^^^^^^^^
 note: candidate #2 is defined in an impl for the type `Foo<<u16 as Identity>::Assoc>`
-  --> $DIR/candidate-with-alias-2.rs:16:5
+  --> $DIR/candidate-with-alias-2.rs:19:5
    |
 LL |     type Inherent = u32;
    |     ^^^^^^^^^^^^^
diff --git a/tests/ui/associated-inherent-types/candidate-with-alias.rs b/tests/ui/associated-inherent-types/candidate-with-alias.rs
index d4dd002a774..a84da195c26 100644
--- a/tests/ui/associated-inherent-types/candidate-with-alias.rs
+++ b/tests/ui/associated-inherent-types/candidate-with-alias.rs
@@ -3,6 +3,9 @@
 #![feature(inherent_associated_types)]
 #![expect(incomplete_features)]
 
+// A behaviour test showcasing that IAT resolution can pick the right
+// candidate even if it has an alias, if it's the only candidate.
+
 trait Identity {
     type Assoc;
 }
diff --git a/tests/ui/associated-inherent-types/multiple-candidates-in-adt-field-2.rs b/tests/ui/associated-inherent-types/multiple-candidates-in-adt-field-2.rs
index b942c303d3e..8a6d1896f7d 100644
--- a/tests/ui/associated-inherent-types/multiple-candidates-in-adt-field-2.rs
+++ b/tests/ui/associated-inherent-types/multiple-candidates-in-adt-field-2.rs
@@ -1,8 +1,8 @@
 #![feature(inherent_associated_types)]
 #![expect(incomplete_features)]
 
-// Test that when we have an unnormalized projection we don't normalize it
-// to determine which IAT to resolve to.
+// Test that when we have an unnormalized projection in the IAT self ty
+// we don't normalize it to determine which IAT to resolve to.
 
 struct Foo<T>(T);
 impl Foo<u8> {
-- 
cgit 1.4.1-3-g733a5