Auto merge of rust-lang#12336 - bitgaoshu:mismatch, r=flodiebold

fix: rust-lang#12267  type-mismatch when using equals w/ a trait bound

Author: bors

crates/hir-ty/src/chalk_db.rs

@@ -410,8 +410,10 @@ pub(crate) fn associated_ty_data_query(
     let resolver = hir_def::resolver::HasResolver::resolver(type_alias, db.upcast());
     let ctx = crate::TyLoweringContext::new(db, &resolver)
         .with_type_param_mode(crate::lower::ParamLoweringMode::Variable);
-    let self_ty =
-        TyKind::BoundVar(BoundVar::new(crate::DebruijnIndex::INNERMOST, 0)).intern(Interner);
+    let pro_ty = TyBuilder::assoc_type_projection(db, type_alias)
+        .fill_with_bound_vars(crate::DebruijnIndex::INNERMOST, 0)
+        .build();
+    let self_ty = TyKind::Alias(AliasTy::Projection(pro_ty)).intern(Interner);
     let mut bounds: Vec<_> = type_alias_data
         .bounds
         .iter()

crates/hir-ty/src/tests/traits.rs

@@ -1,7 +1,7 @@
 use cov_mark::check;
 use expect_test::expect;
 
-use super::{check, check_infer, check_infer_with_mismatches, check_types};
+use super::{check, check_infer, check_infer_with_mismatches, check_no_mismatches, check_types};
 
 #[test]
 fn infer_await() {
@@ -3316,6 +3316,42 @@ pub trait Deserialize {
     );
 }
 
+#[test]
+fn bin_op_with_rhs_is_self_for_assoc_bound() {
+    check_no_mismatches(
+        r#"//- minicore: eq
+        fn repro<T>(t: T) -> bool
+where
+    T: Request,
+    T::Output: Convertable,
+{
+    let a = execute(&t).convert();
+    let b = execute(&t).convert();
+    a.eq(&b);
+    let a = execute(&t).convert2();
+    let b = execute(&t).convert2();
+    a.eq(&b)
+}
+fn execute<T>(t: &T) -> T::Output
+where
+    T: Request,
+{
+    <T as Request>::output()
+}
+trait Convertable {
+    type TraitSelf: PartialEq<Self::TraitSelf>;
+    type AssocAsDefaultSelf: PartialEq;
+    fn convert(self) -> Self::AssocAsDefaultSelf;
+    fn convert2(self) -> Self::TraitSelf;
+}
+trait Request {
+    type Output;
+    fn output() -> Self::Output;
+}
+     "#,
+    );
+}
+
 #[test]
 fn bin_op_adt_with_rhs_primitive() {
     check_infer_with_mismatches(