Move ty::Error branch into super_combine_tys

compiler/rustc_infer/src/infer/relate/combine.rs

@@ -43,6 +43,11 @@ impl<'tcx> InferCtxt<'tcx> {
         debug_assert!(!b.has_escaping_bound_vars());
 
         match (a.kind(), b.kind()) {
+            (&ty::Error(e), _) | (_, &ty::Error(e)) => {
+                self.set_tainted_by_errors(e);
+                return Ok(Ty::new_error(self.tcx, e));
+            }
+
             // Relate integral variables to other types
             (&ty::Infer(ty::IntVar(a_id)), &ty::Infer(ty::IntVar(b_id))) => {
                 self.inner.borrow_mut().int_unification_table().union(a_id, b_id);

compiler/rustc_infer/src/infer/relate/type_relating.rs

@@ -183,11 +183,6 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for TypeRelating<'_, 'tcx> {
                 )?;
             }
 
-            (&ty::Error(e), _) | (_, &ty::Error(e)) => {
-                infcx.set_tainted_by_errors(e);
-                return Ok(Ty::new_error(self.cx(), e));
-            }
-
             (
                 &ty::Alias(ty::Opaque, ty::AliasTy { def_id: a_def_id, .. }),
                 &ty::Alias(ty::Opaque, ty::AliasTy { def_id: b_def_id, .. }),

tests/ui/associated-types/remove-invalid-type-bound-suggest-issue-127555.rs

@@ -14,7 +14,6 @@ impl Foo for Baz {
     //~^ ERROR `F` cannot be sent between threads safely
     where
         F: FnMut() + Send,
-        //~^ ERROR impl has stricter requirements than trait
     {
         ()
     }

tests/ui/associated-types/remove-invalid-type-bound-suggest-issue-127555.stderr

@@ -16,18 +16,6 @@ LL |     async fn bar<F>(&mut self, _func: F) -> ()
 LL |         F: FnMut() + Send,
    |                      ^^^^ required by this bound in `<Baz as Foo>::bar`
 
-error[E0276]: impl has stricter requirements than trait
+error: aborting due to 1 previous error
-  --> $DIR/remove-invalid-type-bound-suggest-issue-127555.rs:16:22
-   |
-LL | /     fn bar<F>(&mut self, func: F) -> impl std::future::Future<Output = ()> + Send
-LL | |     where
-LL | |         F: FnMut();
-   | |___________________- definition of `bar` from trait
-...
-LL |           F: FnMut() + Send,
-   |                        ^^^^ impl has extra requirement `F: Send`
 
-error: aborting due to 2 previous errors
+For more information about this error, try `rustc --explain E0277`.
-
-Some errors have detailed explanations: E0276, E0277.
-For more information about an error, try `rustc --explain E0276`.

tests/ui/impl-trait/in-trait/false-positive-predicate-entailment-error.current.stderr

@@ -73,32 +73,6 @@ help: consider further restricting this bound
 LL |         F: Callback<Self::CallbackArg> + MyFn<i32>,
    |                                        +++++++++++
 
-error[E0277]: the trait bound `F: Callback<i32>` is not satisfied
-  --> $DIR/false-positive-predicate-entailment-error.rs:43:12
-   |
-LL |         F: Callback<Self::CallbackArg>,
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `MyFn<i32>` is not implemented for `F`, which is required by `F: Callback<i32>`
-   |
-note: required for `F` to implement `Callback<i32>`
-  --> $DIR/false-positive-predicate-entailment-error.rs:14:21
-   |
-LL | impl<A, F: MyFn<A>> Callback<A> for F {
-   |            -------  ^^^^^^^^^^^     ^
-   |            |
-   |            unsatisfied trait bound introduced here
-note: the requirement `F: Callback<i32>` appears on the `impl`'s method `autobatch` but not on the corresponding trait's method
-  --> $DIR/false-positive-predicate-entailment-error.rs:25:8
-   |
-LL | trait ChannelSender {
-   |       ------------- in this trait
-...
-LL |     fn autobatch<F>(self) -> impl Trait
-   |        ^^^^^^^^^ this trait's method doesn't have the requirement `F: Callback<i32>`
-help: consider further restricting this bound
-   |
-LL |         F: Callback<Self::CallbackArg> + MyFn<i32>,
-   |                                        +++++++++++
-
 error[E0277]: the trait bound `F: MyFn<i32>` is not satisfied
   --> $DIR/false-positive-predicate-entailment-error.rs:36:30
    |
@@ -168,6 +142,6 @@ help: consider further restricting this bound
 LL |         F: Callback<Self::CallbackArg> + MyFn<i32>,
    |                                        +++++++++++
 
-error: aborting due to 8 previous errors
+error: aborting due to 7 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/impl-trait/in-trait/false-positive-predicate-entailment-error.rs

@@ -41,8 +41,7 @@ impl ChannelSender for Sender {
     //[current]~| ERROR the trait bound `F: MyFn<i32>` is not satisfied
     where
         F: Callback<Self::CallbackArg>,
-        //[current]~^ ERROR the trait bound `F: Callback<i32>` is not satisfied
+        //[current]~^ ERROR the trait bound `F: MyFn<i32>` is not satisfied
-        //[current]~| ERROR the trait bound `F: MyFn<i32>` is not satisfied
     {
         Thing
     }

tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.rs

@@ -8,7 +8,6 @@ impl Foo<char> for Bar {
     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
         //~^ ERROR: the trait bound `impl Foo<u8>: Foo<char>` is not satisfied [E0277]
         //~| ERROR: the trait bound `Bar: Foo<u8>` is not satisfied [E0277]
-        //~| ERROR: impl has stricter requirements than trait
         //~| ERROR: the trait bound `F2: Foo<u8>` is not satisfied
         self
     }

tests/ui/impl-trait/in-trait/return-dont-satisfy-bounds.stderr

@@ -23,15 +23,6 @@ note: required by a bound in `<Bar as Foo<char>>::foo`
 LL |     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
    |                ^^^^^^^ required by this bound in `<Bar as Foo<char>>::foo`
 
-error[E0276]: impl has stricter requirements than trait
-  --> $DIR/return-dont-satisfy-bounds.rs:8:16
-   |
-LL |     fn foo<F2>(self) -> impl Foo<T>;
-   |     -------------------------------- definition of `foo` from trait
-...
-LL |     fn foo<F2: Foo<u8>>(self) -> impl Foo<u8> {
-   |                ^^^^^^^ impl has extra requirement `F2: Foo<u8>`
-
 error[E0277]: the trait bound `Bar: Foo<u8>` is not satisfied
   --> $DIR/return-dont-satisfy-bounds.rs:8:34
    |
@@ -44,7 +35,6 @@ LL |         self
    = help: the trait `Foo<char>` is implemented for `Bar`
    = help: for that trait implementation, expected `char`, found `u8`
 
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0276, E0277.
+For more information about this error, try `rustc --explain E0277`.
-For more information about an error, try `rustc --explain E0276`.

tests/ui/impl-trait/precise-capturing/rpitit-captures-more-method-lifetimes.rs

@@ -10,7 +10,6 @@ pub trait Foo {
 impl Foo for () {
     fn bar<'im: 'im>(&'im mut self) -> impl Sized + 'im {}
     //~^ ERROR return type captures more lifetimes than trait definition
-    //~| WARN impl trait in impl method signature does not match trait method signature
 }
 
 fn main() {}

tests/ui/impl-trait/precise-capturing/rpitit-captures-more-method-lifetimes.stderr

@@ -21,22 +21,5 @@ LL |     fn bar<'tr: 'tr>(&'tr mut self) -> impl Sized + use<Self>;
    |                                        ^^^^^^^^^^^^^^^^^^^^^^
    = note: hidden type inferred to be `impl Sized + 'im`
 
-warning: impl trait in impl method signature does not match trait method signature
+error: aborting due to 2 previous errors
-  --> $DIR/rpitit-captures-more-method-lifetimes.rs:11:40
-   |
-LL |     fn bar<'tr: 'tr>(&'tr mut self) -> impl Sized + use<Self>;
-   |                                        ---------------------- return type from trait method defined here
-...
-LL |     fn bar<'im: 'im>(&'im mut self) -> impl Sized + 'im {}
-   |                                        ^^^^^^^^^^^^^^^^
-   |
-   = note: add `#[allow(refining_impl_trait)]` if it is intended for this to be part of the public API of this crate
-   = note: we are soliciting feedback, see issue #121718 <https://github.com/rust-lang/rust/issues/121718> for more information
-   = note: `#[warn(refining_impl_trait_reachable)]` on by default
-help: replace the return type so that it matches the trait
-   |
-LL |     fn bar<'im: 'im>(&'im mut self) -> impl Sized {}
-   |                                        ~~~~~~~~~~
-
-error: aborting due to 2 previous errors; 1 warning emitted