diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index c1b3f34e5a6d4..e2a592d851a8c 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -176,15 +176,14 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
 
     return_if_di_node_created_in_meantime!(cx, unique_type_id);
 
-    let (thin_pointer_size, thin_pointer_align) =
-        cx.size_and_align_of(cx.tcx.mk_imm_ptr(cx.tcx.types.unit));
+    let data_layout = &cx.tcx.data_layout;
     let ptr_type_debuginfo_name = compute_debuginfo_type_name(cx.tcx, ptr_type, true);
 
     match fat_pointer_kind(cx, pointee_type) {
         None => {
             // This is a thin pointer. Create a regular pointer type and give it the correct name.
             debug_assert_eq!(
-                (thin_pointer_size, thin_pointer_align),
+                (data_layout.pointer_size, data_layout.pointer_align.abi),
                 cx.size_and_align_of(ptr_type),
                 "ptr_type={}, pointee_type={}",
                 ptr_type,
@@ -195,8 +194,8 @@ fn build_pointer_or_reference_di_node<'ll, 'tcx>(
                 llvm::LLVMRustDIBuilderCreatePointerType(
                     DIB(cx),
                     pointee_type_di_node,
-                    thin_pointer_size.bits(),
-                    thin_pointer_align.bits() as u32,
+                    data_layout.pointer_size.bits(),
+                    data_layout.pointer_align.abi.bits() as u32,
                     0, // Ignore DWARF address space.
                     ptr_type_debuginfo_name.as_ptr().cast(),
                     ptr_type_debuginfo_name.len(),
diff --git a/compiler/rustc_hir_analysis/src/astconv/mod.rs b/compiler/rustc_hir_analysis/src/astconv/mod.rs
index 6d9dfe9697c0c..4ab6bb5908bcd 100644
--- a/compiler/rustc_hir_analysis/src/astconv/mod.rs
+++ b/compiler/rustc_hir_analysis/src/astconv/mod.rs
@@ -1427,13 +1427,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         for (base_trait_ref, span, constness) in regular_traits_refs_spans {
             assert_eq!(constness, ty::BoundConstness::NotConst);
 
-            for obligation in traits::elaborate_trait_ref(tcx, base_trait_ref) {
-                debug!(
-                    "conv_object_ty_poly_trait_ref: observing object predicate `{:?}`",
-                    obligation.predicate
-                );
+            for pred in traits::elaborate_trait_ref(tcx, base_trait_ref) {
+                debug!("conv_object_ty_poly_trait_ref: observing object predicate `{:?}`", pred);
 
-                let bound_predicate = obligation.predicate.kind();
+                let bound_predicate = pred.kind();
                 match bound_predicate.skip_binder() {
                     ty::PredicateKind::Clause(ty::Clause::Trait(pred)) => {
                         let pred = bound_predicate.rebind(pred);
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 491bd04f346bd..c912a8a640d45 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -1912,14 +1912,13 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         // Check elaborated bounds.
         let implied_obligations = traits::elaborate_predicates_with_span(tcx, predicates_with_span);
 
-        for obligation in implied_obligations {
+        for (pred, obligation_span) in implied_obligations {
             // We lower empty bounds like `Vec<dyn Copy>:` as
             // `WellFormed(Vec<dyn Copy>)`, which will later get checked by
             // regular WF checking
-            if let ty::PredicateKind::WellFormed(..) = obligation.predicate.kind().skip_binder() {
+            if let ty::PredicateKind::WellFormed(..) = pred.kind().skip_binder() {
                 continue;
             }
-            let pred = obligation.predicate;
             // Match the existing behavior.
             if pred.is_global() && !pred.has_late_bound_vars() {
                 let pred = self.normalize(span, None, pred);
@@ -1930,8 +1929,6 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
                 if let Some(hir::Generics { predicates, .. }) =
                     hir_node.and_then(|node| node.generics())
                 {
-                    let obligation_span = obligation.cause.span();
-
                     span = predicates
                         .iter()
                         // There seems to be no better way to find out which predicate we are in
diff --git a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
index aa66d7bb5efc8..d2e45c28658bd 100644
--- a/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
+++ b/compiler/rustc_hir_analysis/src/collect/item_bounds.rs
@@ -130,12 +130,9 @@ pub(super) fn item_bounds(
     tcx: TyCtxt<'_>,
     def_id: DefId,
 ) -> ty::EarlyBinder<&'_ ty::List<ty::Predicate<'_>>> {
-    let bounds = tcx.mk_predicates_from_iter(
-        util::elaborate_predicates(
-            tcx,
-            tcx.explicit_item_bounds(def_id).iter().map(|&(bound, _span)| bound),
-        )
-        .map(|obligation| obligation.predicate),
-    );
+    let bounds = tcx.mk_predicates_from_iter(util::elaborate_predicates(
+        tcx,
+        tcx.explicit_item_bounds(def_id).iter().map(|&(bound, _span)| bound),
+    ));
     ty::EarlyBinder(bounds)
 }
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index 7f1e4ccc9647b..dfa9e6148aab5 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -318,16 +318,8 @@ fn check_predicates<'tcx>(
     span: Span,
 ) {
     let instantiated = tcx.predicates_of(impl1_def_id).instantiate(tcx, impl1_substs);
-    let impl1_predicates: Vec<_> = traits::elaborate_predicates_with_span(
-        tcx,
-        std::iter::zip(
-            instantiated.predicates,
-            // Don't drop predicates (unsound!) because `spans` is too short
-            instantiated.spans.into_iter().chain(std::iter::repeat(span)),
-        ),
-    )
-    .map(|obligation| (obligation.predicate, obligation.cause.span))
-    .collect();
+    let impl1_predicates: Vec<_> =
+        traits::elaborate_predicates_with_span(tcx, instantiated.into_iter()).collect();
 
     let mut impl2_predicates = if impl2_node.is_from_trait() {
         // Always applicable traits have to be always applicable without any
@@ -341,7 +333,6 @@ fn check_predicates<'tcx>(
                 .predicates
                 .into_iter(),
         )
-        .map(|obligation| obligation.predicate)
         .collect()
     };
     debug!(?impl1_predicates, ?impl2_predicates);
@@ -361,12 +352,16 @@ fn check_predicates<'tcx>(
     // which is sound because we forbid impls like the following
     //
     // impl<D: Debug> AlwaysApplicable for D { }
-    let always_applicable_traits = impl1_predicates.iter().copied().filter(|&(predicate, _)| {
-        matches!(
-            trait_predicate_kind(tcx, predicate),
-            Some(TraitSpecializationKind::AlwaysApplicable)
-        )
-    });
+    let always_applicable_traits = impl1_predicates
+        .iter()
+        .copied()
+        .filter(|&(predicate, _)| {
+            matches!(
+                trait_predicate_kind(tcx, predicate),
+                Some(TraitSpecializationKind::AlwaysApplicable)
+            )
+        })
+        .map(|(pred, _span)| pred);
 
     // Include the well-formed predicates of the type parameters of the impl.
     for arg in tcx.impl_trait_ref(impl1_def_id).unwrap().subst_identity().substs {
@@ -380,10 +375,7 @@ fn check_predicates<'tcx>(
             traits::elaborate_obligations(tcx, obligations).map(|obligation| obligation.predicate),
         )
     }
-    impl2_predicates.extend(
-        traits::elaborate_predicates_with_span(tcx, always_applicable_traits)
-            .map(|obligation| obligation.predicate),
-    );
+    impl2_predicates.extend(traits::elaborate_predicates(tcx, always_applicable_traits));
 
     for (predicate, span) in impl1_predicates {
         if !impl2_predicates.iter().any(|pred2| trait_predicates_eq(tcx, predicate, *pred2, span)) {
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index ec391ea80f48b..47a8b0801664f 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -204,15 +204,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let mut expected_sig = None;
         let mut expected_kind = None;
 
-        for obligation in traits::elaborate_predicates_with_span(
+        for (pred, span) in traits::elaborate_predicates_with_span(
             self.tcx,
             // Reverse the obligations here, since `elaborate_*` uses a stack,
             // and we want to keep inference generally in the same order of
             // the registered obligations.
             predicates.rev(),
         ) {
-            debug!(?obligation.predicate);
-            let bound_predicate = obligation.predicate.kind();
+            debug!(?pred);
+            let bound_predicate = pred.kind();
 
             // Given a Projection predicate, we can potentially infer
             // the complete signature.
@@ -220,9 +220,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 && let ty::PredicateKind::Clause(ty::Clause::Projection(proj_predicate)) = bound_predicate.skip_binder()
             {
                 let inferred_sig = self.normalize(
-                    obligation.cause.span,
+                    span,
                     self.deduce_sig_from_projection(
-                    Some(obligation.cause.span),
+                    Some(span),
                         bound_predicate.rebind(proj_predicate),
                     ),
                 );
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index a0aa43deadcfd..2762e778591ee 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -576,17 +576,13 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
 
         traits::elaborate_predicates(self.tcx, predicates.predicates.iter().copied())
             // We don't care about regions here.
-            .filter_map(|obligation| match obligation.predicate.kind().skip_binder() {
+            .filter_map(|pred| match pred.kind().skip_binder() {
                 ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred))
                     if trait_pred.def_id() == sized_def_id =>
                 {
                     let span = predicates
                         .iter()
-                        .find_map(
-                            |(p, span)| {
-                                if p == obligation.predicate { Some(span) } else { None }
-                            },
-                        )
+                        .find_map(|(p, span)| if p == pred { Some(span) } else { None })
                         .unwrap_or(rustc_span::DUMMY_SP);
                     Some((trait_pred, span))
                 }
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index fd16363a1db01..75c3d9f641dda 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -1942,7 +1942,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     escaped
                 }
                 let mut err = struct_span_err!(self.tcx.sess, span, E0308, "{}", failure_str);
-                if let Some((expected, found)) = trace.values.ty() {
+                let values = self.resolve_vars_if_possible(trace.values);
+                if let Some((expected, found)) = values.ty() {
                     match (expected.kind(), found.kind()) {
                         (ty::Tuple(_), ty::Tuple(_)) => {}
                         // If a tuple of length one was expected and the found expression has
diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs
index 0d2faeba5fc0f..f3797499866ac 100644
--- a/compiler/rustc_infer/src/traits/util.rs
+++ b/compiler/rustc_infer/src/traits/util.rs
@@ -74,44 +74,58 @@ pub struct Elaborator<'tcx> {
 pub fn elaborate_trait_ref<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>,
-) -> Elaborator<'tcx> {
+) -> impl Iterator<Item = ty::Predicate<'tcx>> {
     elaborate_predicates(tcx, std::iter::once(trait_ref.without_const().to_predicate(tcx)))
 }
 
 pub fn elaborate_trait_refs<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_refs: impl Iterator<Item = ty::PolyTraitRef<'tcx>>,
-) -> Elaborator<'tcx> {
-    let predicates = trait_refs.map(|trait_ref| trait_ref.without_const().to_predicate(tcx));
+) -> impl Iterator<Item = ty::Predicate<'tcx>> {
+    let predicates = trait_refs.map(move |trait_ref| trait_ref.without_const().to_predicate(tcx));
     elaborate_predicates(tcx, predicates)
 }
 
 pub fn elaborate_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: impl Iterator<Item = ty::Predicate<'tcx>>,
-) -> Elaborator<'tcx> {
-    let obligations = predicates
-        .map(|predicate| {
-            predicate_obligation(predicate, ty::ParamEnv::empty(), ObligationCause::dummy())
-        })
-        .collect();
-    elaborate_obligations(tcx, obligations)
+) -> impl Iterator<Item = ty::Predicate<'tcx>> {
+    elaborate_obligations(
+        tcx,
+        predicates
+            .map(|predicate| {
+                Obligation::new(
+                    tcx,
+                    // We'll dump the cause/param-env later
+                    ObligationCause::dummy(),
+                    ty::ParamEnv::empty(),
+                    predicate,
+                )
+            })
+            .collect(),
+    )
+    .map(|obl| obl.predicate)
 }
 
 pub fn elaborate_predicates_with_span<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: impl Iterator<Item = (ty::Predicate<'tcx>, Span)>,
-) -> Elaborator<'tcx> {
-    let obligations = predicates
-        .map(|(predicate, span)| {
-            predicate_obligation(
-                predicate,
-                ty::ParamEnv::empty(),
-                ObligationCause::dummy_with_span(span),
-            )
-        })
-        .collect();
-    elaborate_obligations(tcx, obligations)
+) -> impl Iterator<Item = (ty::Predicate<'tcx>, Span)> {
+    elaborate_obligations(
+        tcx,
+        predicates
+            .map(|(predicate, span)| {
+                Obligation::new(
+                    tcx,
+                    // We'll dump the cause/param-env later
+                    ObligationCause::dummy_with_span(span),
+                    ty::ParamEnv::empty(),
+                    predicate,
+                )
+            })
+            .collect(),
+    )
+    .map(|obl| (obl.predicate, obl.cause.span))
 }
 
 pub fn elaborate_obligations<'tcx>(
@@ -141,10 +155,6 @@ impl<'tcx> Elaborator<'tcx> {
         self.stack.extend(obligations.into_iter().filter(|o| self.visited.insert(o.predicate)));
     }
 
-    pub fn filter_to_traits(self) -> FilterToTraits<Self> {
-        FilterToTraits::new(self)
-    }
-
     fn elaborate(&mut self, obligation: &PredicateObligation<'tcx>) {
         let tcx = self.visited.tcx;
 
@@ -325,20 +335,18 @@ impl<'tcx> Iterator for Elaborator<'tcx> {
 // Supertrait iterator
 ///////////////////////////////////////////////////////////////////////////
 
-pub type Supertraits<'tcx> = FilterToTraits<Elaborator<'tcx>>;
-
 pub fn supertraits<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ref: ty::PolyTraitRef<'tcx>,
-) -> Supertraits<'tcx> {
-    elaborate_trait_ref(tcx, trait_ref).filter_to_traits()
+) -> impl Iterator<Item = ty::PolyTraitRef<'tcx>> {
+    FilterToTraits::new(elaborate_trait_ref(tcx, trait_ref))
 }
 
 pub fn transitive_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
-    bounds: impl Iterator<Item = ty::PolyTraitRef<'tcx>>,
-) -> Supertraits<'tcx> {
-    elaborate_trait_refs(tcx, bounds).filter_to_traits()
+    trait_refs: impl Iterator<Item = ty::PolyTraitRef<'tcx>>,
+) -> impl Iterator<Item = ty::PolyTraitRef<'tcx>> {
+    FilterToTraits::new(elaborate_trait_refs(tcx, trait_refs))
 }
 
 /// A specialized variant of `elaborate_trait_refs` that only elaborates trait references that may
@@ -393,12 +401,12 @@ impl<I> FilterToTraits<I> {
     }
 }
 
-impl<'tcx, I: Iterator<Item = PredicateObligation<'tcx>>> Iterator for FilterToTraits<I> {
+impl<'tcx, I: Iterator<Item = ty::Predicate<'tcx>>> Iterator for FilterToTraits<I> {
     type Item = ty::PolyTraitRef<'tcx>;
 
     fn next(&mut self) -> Option<ty::PolyTraitRef<'tcx>> {
-        while let Some(obligation) = self.base_iterator.next() {
-            if let Some(data) = obligation.predicate.to_opt_poly_trait_pred() {
+        while let Some(pred) = self.base_iterator.next() {
+            if let Some(data) = pred.to_opt_poly_trait_pred() {
                 return Some(data.map_bound(|t| t.trait_ref));
             }
         }
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index faca61fc29bf9..42e59f92840e0 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -258,11 +258,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
                         cx.tcx,
                         cx.tcx.explicit_item_bounds(def).iter().cloned(),
                     )
-                    .find_map(|obligation| {
+                    .find_map(|(pred, _span)| {
                         // We only look at the `DefId`, so it is safe to skip the binder here.
                         if let ty::PredicateKind::Clause(ty::Clause::Trait(
                             ref poly_trait_predicate,
-                        )) = obligation.predicate.kind().skip_binder()
+                        )) = pred.kind().skip_binder()
                         {
                             let def_id = poly_trait_predicate.trait_ref.def_id;
 
diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs
index c1cf6ee0f9ec1..e7075d5e79120 100644
--- a/compiler/rustc_mir_transform/src/const_prop.rs
+++ b/compiler/rustc_mir_transform/src/const_prop.rs
@@ -117,7 +117,7 @@ impl<'tcx> MirPass<'tcx> for ConstProp {
             .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
         if traits::impossible_predicates(
             tcx,
-            traits::elaborate_predicates(tcx, predicates).map(|o| o.predicate).collect(),
+            traits::elaborate_predicates(tcx, predicates).collect(),
         ) {
             trace!("ConstProp skipped for {:?}: found unsatisfiable predicates", def_id);
             return;
diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs
index 45bd98f39d2ba..60401b054922a 100644
--- a/compiler/rustc_mir_transform/src/const_prop_lint.rs
+++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs
@@ -93,7 +93,7 @@ impl<'tcx> MirLint<'tcx> for ConstProp {
             .filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
         if traits::impossible_predicates(
             tcx,
-            traits::elaborate_predicates(tcx, predicates).map(|o| o.predicate).collect(),
+            traits::elaborate_predicates(tcx, predicates).collect(),
         ) {
             trace!("ConstProp skipped for {:?}: found unsatisfiable predicates", def_id);
             return;
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 80618fd1abed2..2ff7de8cb9efc 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -1065,7 +1065,7 @@ pub(super) struct CurrentDepGraph<K: DepKind> {
     /// This is used to verify that fingerprints do not change between the creation of a node
     /// and its recomputation.
     #[cfg(debug_assertions)]
-    fingerprints: Lock<FxHashMap<DepNode<K>, Fingerprint>>,
+    fingerprints: Lock<IndexVec<DepNodeIndex, Option<Fingerprint>>>,
 
     /// Used to trap when a specific edge is added to the graph.
     /// This is used for debug purposes and is only active with `debug_assertions`.
@@ -1151,7 +1151,7 @@ impl<K: DepKind> CurrentDepGraph<K> {
             #[cfg(debug_assertions)]
             forbidden_edge,
             #[cfg(debug_assertions)]
-            fingerprints: Lock::new(Default::default()),
+            fingerprints: Lock::new(IndexVec::from_elem_n(None, new_node_count_estimate)),
             total_read_count: AtomicU64::new(0),
             total_duplicate_read_count: AtomicU64::new(0),
             node_intern_event_id,
@@ -1163,14 +1163,8 @@ impl<K: DepKind> CurrentDepGraph<K> {
         if let Some(forbidden_edge) = &self.forbidden_edge {
             forbidden_edge.index_to_node.lock().insert(dep_node_index, key);
         }
-        match self.fingerprints.lock().entry(key) {
-            Entry::Vacant(v) => {
-                v.insert(fingerprint);
-            }
-            Entry::Occupied(o) => {
-                assert_eq!(*o.get(), fingerprint, "Unstable fingerprints for {:?}", key);
-            }
-        }
+        let previous = *self.fingerprints.lock().get_or_insert_with(dep_node_index, || fingerprint);
+        assert_eq!(previous, fingerprint, "Unstable fingerprints for {:?}", key);
     }
 
     /// Writes the node to the current dep-graph and allocates a `DepNodeIndex` for it.
diff --git a/compiler/rustc_trait_selection/src/solve/assembly.rs b/compiler/rustc_trait_selection/src/solve/assembly.rs
index 995fec78c4076..b2658614fd3df 100644
--- a/compiler/rustc_trait_selection/src/solve/assembly.rs
+++ b/compiler/rustc_trait_selection/src/solve/assembly.rs
@@ -470,7 +470,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         for assumption in
             elaborate_predicates(tcx, bounds.iter().map(|bound| bound.with_self_ty(tcx, self_ty)))
         {
-            match G::consider_object_bound_candidate(self, goal, assumption.predicate) {
+            match G::consider_object_bound_candidate(self, goal, assumption) {
                 Ok(result) => {
                     candidates.push(Candidate { source: CandidateSource::BuiltinImpl, result })
                 }
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 6b3a59b1ed545..878c502655cf6 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -349,8 +349,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
             let normalized_preds = elaborate_predicates(
                 tcx,
                 computed_preds.clone().chain(user_computed_preds.iter().cloned()),
-            )
-            .map(|o| o.predicate);
+            );
             new_env = ty::ParamEnv::new(
                 tcx.mk_predicates_from_iter(normalized_preds),
                 param_env.reveal(),
diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index 98e00e8223bbc..03ba125cf2b5f 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -367,8 +367,8 @@ fn negative_impl_exists<'tcx>(
     }
 
     // Try to prove a negative obligation exists for super predicates
-    for o in util::elaborate_predicates(infcx.tcx, iter::once(o.predicate)) {
-        if resolve_negative_obligation(infcx.fork(), &o, body_def_id) {
+    for pred in util::elaborate_predicates(infcx.tcx, iter::once(o.predicate)) {
+        if resolve_negative_obligation(infcx.fork(), &o.with(infcx.tcx, pred), body_def_id) {
             return true;
         }
     }
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
index 84045c4d0edea..672b3365ff4a9 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
@@ -82,15 +82,15 @@ pub fn recompute_applicable_impls<'tcx>(
 
     let predicates =
         tcx.predicates_of(obligation.cause.body_id.to_def_id()).instantiate_identity(tcx);
-    for obligation in elaborate_predicates_with_span(tcx, predicates.into_iter()) {
-        let kind = obligation.predicate.kind();
+    for (pred, span) in elaborate_predicates_with_span(tcx, predicates.into_iter()) {
+        let kind = pred.kind();
         if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = kind.skip_binder()
             && param_env_candidate_may_apply(kind.rebind(trait_pred))
         {
             if kind.rebind(trait_pred.trait_ref) == ty::TraitRef::identity(tcx, trait_pred.def_id()) {
                 ambiguities.push(Ambiguity::ParamEnv(tcx.def_span(trait_pred.def_id())))
             } else {
-                ambiguities.push(Ambiguity::ParamEnv(obligation.cause.span))
+                ambiguities.push(Ambiguity::ParamEnv(span))
             }
         }
     }
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 296fd1ed5248f..c19798213b70c 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -1624,8 +1624,8 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             }
         };
 
-        for obligation in super::elaborate_predicates(self.tcx, std::iter::once(cond)) {
-            let bound_predicate = obligation.predicate.kind();
+        for pred in super::elaborate_predicates(self.tcx, std::iter::once(cond)) {
+            let bound_predicate = pred.kind();
             if let ty::PredicateKind::Clause(ty::Clause::Trait(implication)) =
                 bound_predicate.skip_binder()
             {
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index e89706067046a..8d831dca6e309 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -66,7 +66,7 @@ pub use self::util::{expand_trait_aliases, TraitAliasExpander};
 pub use self::util::{get_vtable_index_of_object_method, impl_item_is_final, upcast_choices};
 pub use self::util::{
     supertrait_def_ids, supertraits, transitive_bounds, transitive_bounds_that_define_assoc_type,
-    SupertraitDefIds, Supertraits,
+    SupertraitDefIds,
 };
 
 pub use self::chalk_fulfill::FulfillmentContext as ChalkFulfillmentContext;
@@ -267,9 +267,7 @@ pub fn normalize_param_env_or_error<'tcx>(
     // and errors will get reported then; so outside of type inference we
     // can be sure that no errors should occur.
     let mut predicates: Vec<_> =
-        util::elaborate_predicates(tcx, unnormalized_env.caller_bounds().into_iter())
-            .map(|obligation| obligation.predicate)
-            .collect();
+        util::elaborate_predicates(tcx, unnormalized_env.caller_bounds().into_iter()).collect();
 
     debug!("normalize_param_env_or_error: elaborated-predicates={:?}", predicates);
 
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index 5d2af5ff33c8f..dbf6b78572a19 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -379,26 +379,24 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     // Search for a predicate like `Self : Sized` amongst the trait bounds.
     let predicates = tcx.predicates_of(def_id);
     let predicates = predicates.instantiate_identity(tcx).predicates;
-    elaborate_predicates(tcx, predicates.into_iter()).any(|obligation| {
-        match obligation.predicate.kind().skip_binder() {
-            ty::PredicateKind::Clause(ty::Clause::Trait(ref trait_pred)) => {
-                trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0)
-            }
-            ty::PredicateKind::Clause(ty::Clause::Projection(..))
-            | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
-            | ty::PredicateKind::Subtype(..)
-            | ty::PredicateKind::Coerce(..)
-            | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
-            | ty::PredicateKind::WellFormed(..)
-            | ty::PredicateKind::ObjectSafe(..)
-            | ty::PredicateKind::ClosureKind(..)
-            | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
-            | ty::PredicateKind::ConstEvaluatable(..)
-            | ty::PredicateKind::ConstEquate(..)
-            | ty::PredicateKind::AliasRelate(..)
-            | ty::PredicateKind::Ambiguous
-            | ty::PredicateKind::TypeWellFormedFromEnv(..) => false,
+    elaborate_predicates(tcx, predicates.into_iter()).any(|pred| match pred.kind().skip_binder() {
+        ty::PredicateKind::Clause(ty::Clause::Trait(ref trait_pred)) => {
+            trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0)
         }
+        ty::PredicateKind::Clause(ty::Clause::Projection(..))
+        | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
+        | ty::PredicateKind::Subtype(..)
+        | ty::PredicateKind::Coerce(..)
+        | ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..))
+        | ty::PredicateKind::WellFormed(..)
+        | ty::PredicateKind::ObjectSafe(..)
+        | ty::PredicateKind::ClosureKind(..)
+        | ty::PredicateKind::Clause(ty::Clause::TypeOutlives(..))
+        | ty::PredicateKind::ConstEvaluatable(..)
+        | ty::PredicateKind::ConstEquate(..)
+        | ty::PredicateKind::AliasRelate(..)
+        | ty::PredicateKind::Ambiguous
+        | ty::PredicateKind::TypeWellFormedFromEnv(..) => false,
     })
 }
 
@@ -669,9 +667,9 @@ fn object_ty_for_trait<'tcx>(
     debug!(?trait_predicate);
 
     let mut elaborated_predicates: Vec<_> = elaborate_trait_ref(tcx, trait_ref)
-        .filter_map(|obligation| {
-            debug!(?obligation);
-            let pred = obligation.predicate.to_opt_poly_projection_pred()?;
+        .filter_map(|pred| {
+            debug!(?pred);
+            let pred = pred.to_opt_poly_projection_pred()?;
             Some(pred.map_bound(|p| {
                 ty::ExistentialPredicate::Projection(ty::ExistentialProjection::erase_self_ty(
                     tcx, p,
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index ec5bd982a3c98..156674e33c334 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -921,9 +921,9 @@ pub(crate) fn required_region_bounds<'tcx>(
     assert!(!erased_self_ty.has_escaping_bound_vars());
 
     traits::elaborate_predicates(tcx, predicates)
-        .filter_map(|obligation| {
-            debug!(?obligation);
-            match obligation.predicate.kind().skip_binder() {
+        .filter_map(|pred| {
+            debug!(?pred);
+            match pred.kind().skip_binder() {
                 ty::PredicateKind::Clause(ty::Clause::Projection(..))
                 | ty::PredicateKind::Clause(ty::Clause::Trait(..))
                 | ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(..))
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 5469261ef5659..55e18b0495601 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -135,7 +135,6 @@
 #![feature(maybe_uninit_uninit_array)]
 #![feature(maybe_uninit_uninit_array_transpose)]
 #![cfg_attr(test, feature(new_uninit))]
-#![feature(nonnull_slice_from_raw_parts)]
 #![feature(pattern)]
 #![feature(pointer_byte_offsets)]
 #![feature(provide_any)]
diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs
index 2a93a242d5174..966cf57511630 100644
--- a/library/alloc/tests/lib.rs
+++ b/library/alloc/tests/lib.rs
@@ -8,7 +8,7 @@
 #![feature(const_cow_is_borrowed)]
 #![feature(const_heap)]
 #![feature(const_mut_refs)]
-#![feature(const_nonnull_slice_from_raw_parts)]
+#![feature(const_slice_from_raw_parts_mut)]
 #![feature(const_ptr_write)]
 #![feature(const_try)]
 #![feature(core_intrinsics)]
@@ -38,7 +38,6 @@
 #![feature(const_default_impls)]
 #![feature(const_trait_impl)]
 #![feature(const_str_from_utf8)]
-#![feature(nonnull_slice_from_raw_parts)]
 #![feature(panic_update_hook)]
 #![feature(pointer_is_aligned)]
 #![feature(slice_flatten)]
diff --git a/library/core/src/ptr/non_null.rs b/library/core/src/ptr/non_null.rs
index 8c1a648860555..a46804c186c28 100644
--- a/library/core/src/ptr/non_null.rs
+++ b/library/core/src/ptr/non_null.rs
@@ -462,8 +462,6 @@ impl<T> NonNull<[T]> {
     /// # Examples
     ///
     /// ```rust
-    /// #![feature(nonnull_slice_from_raw_parts)]
-    ///
     /// use std::ptr::NonNull;
     ///
     /// // create a slice pointer when starting out with a pointer to the first element
@@ -475,8 +473,8 @@ impl<T> NonNull<[T]> {
     ///
     /// (Note that this example artificially demonstrates a use of this method,
     /// but `let slice = NonNull::from(&x[..]);` would be a better way to write code like this.)
-    #[unstable(feature = "nonnull_slice_from_raw_parts", issue = "71941")]
-    #[rustc_const_unstable(feature = "const_nonnull_slice_from_raw_parts", issue = "71941")]
+    #[stable(feature = "nonnull_slice_from_raw_parts", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_unstable(feature = "const_slice_from_raw_parts_mut", issue = "67456")]
     #[must_use]
     #[inline]
     pub const fn slice_from_raw_parts(data: NonNull<T>, len: usize) -> Self {
@@ -494,7 +492,6 @@ impl<T> NonNull<[T]> {
     /// # Examples
     ///
     /// ```rust
-    /// #![feature(nonnull_slice_from_raw_parts)]
     /// use std::ptr::NonNull;
     ///
     /// let slice: NonNull<[i8]> = NonNull::slice_from_raw_parts(NonNull::dangling(), 3);
@@ -514,7 +511,7 @@ impl<T> NonNull<[T]> {
     /// # Examples
     ///
     /// ```rust
-    /// #![feature(slice_ptr_get, nonnull_slice_from_raw_parts)]
+    /// #![feature(slice_ptr_get)]
     /// use std::ptr::NonNull;
     ///
     /// let slice: NonNull<[i8]> = NonNull::slice_from_raw_parts(NonNull::dangling(), 3);
@@ -534,7 +531,7 @@ impl<T> NonNull<[T]> {
     /// # Examples
     ///
     /// ```rust
-    /// #![feature(slice_ptr_get, nonnull_slice_from_raw_parts)]
+    /// #![feature(slice_ptr_get)]
     /// use std::ptr::NonNull;
     ///
     /// let slice: NonNull<[i8]> = NonNull::slice_from_raw_parts(NonNull::dangling(), 3);
@@ -668,7 +665,7 @@ impl<T> NonNull<[T]> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(slice_ptr_get, nonnull_slice_from_raw_parts)]
+    /// #![feature(slice_ptr_get)]
     /// use std::ptr::NonNull;
     ///
     /// let x = &mut [1, 2, 4];
diff --git a/library/panic_abort/src/android.rs b/library/panic_abort/src/android.rs
index 0fd824f8a458d..20b5b6b514685 100644
--- a/library/panic_abort/src/android.rs
+++ b/library/panic_abort/src/android.rs
@@ -15,7 +15,7 @@ type SetAbortMessageType = unsafe extern "C" fn(*const libc::c_char) -> ();
 //
 // Weakly resolve the symbol for android_set_abort_message. This function is only available
 // for API >= 21.
-pub(crate) unsafe fn android_set_abort_message(payload: *mut &mut dyn BoxMeUp) {
+pub(crate) unsafe fn android_set_abort_message(payload: &mut dyn BoxMeUp) {
     let func_addr =
         libc::dlsym(libc::RTLD_DEFAULT, ANDROID_SET_ABORT_MESSAGE.as_ptr() as *const libc::c_char)
             as usize;
@@ -23,7 +23,7 @@ pub(crate) unsafe fn android_set_abort_message(payload: *mut &mut dyn BoxMeUp) {
         return;
     }
 
-    let payload = (*payload).get();
+    let payload = payload.get();
     let msg = match payload.downcast_ref::<&'static str>() {
         Some(msg) => msg.as_bytes(),
         None => match payload.downcast_ref::<String>() {
diff --git a/library/panic_abort/src/lib.rs b/library/panic_abort/src/lib.rs
index a3cebf99c5342..b193d79b0e1a8 100644
--- a/library/panic_abort/src/lib.rs
+++ b/library/panic_abort/src/lib.rs
@@ -29,7 +29,7 @@ pub unsafe extern "C" fn __rust_panic_cleanup(_: *mut u8) -> *mut (dyn Any + Sen
 
 // "Leak" the payload and shim to the relevant abort on the platform in question.
 #[rustc_std_internal_symbol]
-pub unsafe fn __rust_start_panic(_payload: *mut &mut dyn BoxMeUp) -> u32 {
+pub unsafe fn __rust_start_panic(_payload: &mut dyn BoxMeUp) -> u32 {
     // Android has the ability to attach a message as part of the abort.
     #[cfg(target_os = "android")]
     android::android_set_abort_message(_payload);
diff --git a/library/panic_unwind/src/lib.rs b/library/panic_unwind/src/lib.rs
index ea3c9a7a663c2..ce78ab82ef942 100644
--- a/library/panic_unwind/src/lib.rs
+++ b/library/panic_unwind/src/lib.rs
@@ -99,8 +99,8 @@ pub unsafe extern "C" fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any
 // Entry point for raising an exception, just delegates to the platform-specific
 // implementation.
 #[rustc_std_internal_symbol]
-pub unsafe fn __rust_start_panic(payload: *mut &mut dyn BoxMeUp) -> u32 {
-    let payload = Box::from_raw((*payload).take_box());
+pub unsafe fn __rust_start_panic(payload: &mut dyn BoxMeUp) -> u32 {
+    let payload = Box::from_raw(payload.take_box());
 
     imp::panic(payload)
 }
diff --git a/library/std/src/io/cursor.rs b/library/std/src/io/cursor.rs
index d98ab021cadb1..25c64240e7480 100644
--- a/library/std/src/io/cursor.rs
+++ b/library/std/src/io/cursor.rs
@@ -34,7 +34,7 @@ use crate::io::{self, BorrowedCursor, ErrorKind, IoSlice, IoSliceMut, SeekFrom};
 /// use std::fs::File;
 ///
 /// // a library function we've written
-/// fn write_ten_bytes_at_end<W: Write + Seek>(writer: &mut W) -> io::Result<()> {
+/// fn write_ten_bytes_at_end<W: Write + Seek>(mut writer: W) -> io::Result<()> {
 ///     writer.seek(SeekFrom::End(-10))?;
 ///
 ///     for i in 0..10 {
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 4e7b608083500..baad6de707bc2 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -292,7 +292,6 @@
 #![feature(is_some_and)]
 #![feature(maybe_uninit_slice)]
 #![feature(maybe_uninit_write_slice)]
-#![feature(nonnull_slice_from_raw_parts)]
 #![feature(panic_can_unwind)]
 #![feature(panic_info_message)]
 #![feature(panic_internals)]
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index e59f32af77df8..e505466e535a0 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -46,12 +46,10 @@ extern "C" {
     fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static);
 }
 
-#[allow(improper_ctypes)]
 extern "Rust" {
-    /// `payload` is passed through another layer of raw pointers as `&mut dyn Trait` is not
-    /// FFI-safe. `BoxMeUp` lazily performs allocation only when needed (this avoids allocations
-    /// when using the "abort" panic runtime).
-    fn __rust_start_panic(payload: *mut &mut dyn BoxMeUp) -> u32;
+    /// `BoxMeUp` lazily performs allocation only when needed (this avoids
+    /// allocations when using the "abort" panic runtime).
+    fn __rust_start_panic(payload: &mut dyn BoxMeUp) -> u32;
 }
 
 /// This function is called by the panic runtime if FFI code catches a Rust
@@ -738,10 +736,7 @@ pub fn rust_panic_without_hook(payload: Box<dyn Any + Send>) -> ! {
 /// yer breakpoints.
 #[inline(never)]
 #[cfg_attr(not(test), rustc_std_internal_symbol)]
-fn rust_panic(mut msg: &mut dyn BoxMeUp) -> ! {
-    let code = unsafe {
-        let obj = &mut msg as *mut &mut dyn BoxMeUp;
-        __rust_start_panic(obj)
-    };
+fn rust_panic(msg: &mut dyn BoxMeUp) -> ! {
+    let code = unsafe { __rust_start_panic(msg) };
     rtabort!("failed to initiate panic, error {code}")
 }
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 840ed8e1080b7..c081578b8d4bb 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -1946,11 +1946,7 @@ function initSearch(rawSearchIndex) {
     function showResults(results, go_to_first, filterCrates) {
         const search = searchState.outputElement();
         if (go_to_first || (results.others.length === 1
-            && getSettingValue("go-to-only-result") === "true"
-            // By default, the search DOM element is "empty" (meaning it has no children not
-            // text content). Once a search has been run, it won't be empty, even if you press
-            // ESC or empty the search input (which also "cancels" the search).
-            && (!search.firstChild || search.firstChild.innerText !== searchState.loadingText))
+            && getSettingValue("go-to-only-result") === "true")
         ) {
             const elem = document.createElement("a");
             elem.href = results.others[0].href;
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 1ab81aee7b8d5..327e090d38be8 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -124,9 +124,9 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
 
         let preds = traits::elaborate_predicates(cx.tcx, cx.param_env.caller_bounds().iter())
             .filter(|p| !p.is_global())
-            .filter_map(|obligation| {
+            .filter_map(|pred| {
                 // Note that we do not want to deal with qualified predicates here.
-                match obligation.predicate.kind().no_bound_vars() {
+                match pred.kind().no_bound_vars() {
                     Some(ty::PredicateKind::Clause(ty::Clause::Trait(pred))) if pred.def_id() != sized_trait => {
                         Some(pred)
                     },
diff --git a/src/tools/clippy/clippy_utils/src/lib.rs b/src/tools/clippy/clippy_utils/src/lib.rs
index 29830557a4454..fd06c0b86775a 100644
--- a/src/tools/clippy/clippy_utils/src/lib.rs
+++ b/src/tools/clippy/clippy_utils/src/lib.rs
@@ -2106,7 +2106,6 @@ pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_>, did: DefId) -> bool {
     traits::impossible_predicates(
         cx.tcx,
         traits::elaborate_predicates(cx.tcx, predicates)
-            .map(|o| o.predicate)
             .collect::<Vec<_>>(),
     )
 }
diff --git a/tests/rustdoc-gui/setting-go-to-only-result.goml b/tests/rustdoc-gui/setting-go-to-only-result.goml
new file mode 100644
index 0000000000000..3811011a64e6f
--- /dev/null
+++ b/tests/rustdoc-gui/setting-go-to-only-result.goml
@@ -0,0 +1,63 @@
+// Checks that the setting "Directly go to item in search if there is only one result " is working as expected.
+
+define-function: (
+    "check-setting",
+    (storage_value, setting_attribute_value),
+    block {
+        assert-local-storage: {"rustdoc-go-to-only-result": |storage_value|}
+        click: "#settings-menu"
+        wait-for: "#settings"
+        assert-property: ("#go-to-only-result", {"checked": |setting_attribute_value|})
+    }
+)
+
+goto: "file://" + |DOC_PATH| + "/lib2/index.html"
+
+call-function: ("check-setting", {
+    "storage_value": null,
+    "setting_attribute_value": "false",
+})
+
+// By default, the search doesn't automatically go to the page if there is only one result.
+goto: "file://" + |DOC_PATH| + "/lib2/index.html?search=HasALongTraitWithParams"
+// It will timeout if the setting isn't working.
+wait-for: "#search"
+assert-document-property: ({"URL": "/lib2/index.html"}, CONTAINS)
+
+// Now we change its value.
+click: "#settings-menu"
+wait-for: "#settings"
+click: "#go-to-only-result"
+assert-local-storage: {"rustdoc-go-to-only-result": "true"}
+
+goto: "file://" + |DOC_PATH| + "/lib2/index.html"
+// We enter it into the search.
+write: (".search-input", "HasALongTraitWithParams")
+wait-for-document-property: {"title": "HasALongTraitWithParams in lib2 - Rust"}
+assert-document-property: ({"URL": "/lib2/struct.HasALongTraitWithParams.html"}, ENDS_WITH)
+
+// We try again to see if it goes to the only result
+goto: "file://" + |DOC_PATH| + "/lib2/index.html?search=HasALongTraitWithParams"
+wait-for-document-property: {"title": "HasALongTraitWithParams in lib2 - Rust"}
+assert-document-property: ({"URL": "/lib2/struct.HasALongTraitWithParams.html"}, ENDS_WITH)
+
+// We check the settings
+call-function: ("check-setting", {
+    "storage_value": "true",
+    "setting_attribute_value": "true",
+})
+
+// And now we re-disable the setting.
+click: "#go-to-only-result"
+assert-local-storage: {"rustdoc-go-to-only-result": "false"}
+
+goto: "file://" + |DOC_PATH| + "/lib2/index.html?search=HasALongTraitWithParams"
+// It will timeout if the setting isn't working.
+wait-for: "#search"
+assert-document-property: ({"URL": "/lib2/index.html"}, CONTAINS)
+
+// And we check everything is back the way it was before.
+call-function: ("check-setting", {
+    "storage_value": "false",
+    "setting_attribute_value": "false",
+})
diff --git a/tests/ui/inference/char-as-str-single.fixed b/tests/ui/inference/char-as-str-single.fixed
index bab1854dc5173..1621a279f03ff 100644
--- a/tests/ui/inference/char-as-str-single.fixed
+++ b/tests/ui/inference/char-as-str-single.fixed
@@ -10,3 +10,12 @@ fn main() {
     let _: char = '人'; //~ ERROR mismatched types
     let _: char = '\''; //~ ERROR mismatched types
 }
+
+// regression test for https://github.com/rust-lang/rust/issues/109586
+#[allow(dead_code)]
+fn convert_c_to_str(c: char) {
+    match c {
+        'A' => {} //~ ERROR mismatched types
+        _ => {}
+    }
+}
diff --git a/tests/ui/inference/char-as-str-single.rs b/tests/ui/inference/char-as-str-single.rs
index 736920643b2c4..2903142f15991 100644
--- a/tests/ui/inference/char-as-str-single.rs
+++ b/tests/ui/inference/char-as-str-single.rs
@@ -10,3 +10,12 @@ fn main() {
     let _: char = "人"; //~ ERROR mismatched types
     let _: char = "'"; //~ ERROR mismatched types
 }
+
+// regression test for https://github.com/rust-lang/rust/issues/109586
+#[allow(dead_code)]
+fn convert_c_to_str(c: char) {
+    match c {
+        "A" => {} //~ ERROR mismatched types
+        _ => {}
+    }
+}
diff --git a/tests/ui/inference/char-as-str-single.stderr b/tests/ui/inference/char-as-str-single.stderr
index 3375ec6ac32ca..9149efe324071 100644
--- a/tests/ui/inference/char-as-str-single.stderr
+++ b/tests/ui/inference/char-as-str-single.stderr
@@ -37,6 +37,19 @@ help: if you meant to write a `char` literal, use single quotes
 LL |     let _: char = '\'';
    |                   ~~~~
 
-error: aborting due to 3 previous errors
+error[E0308]: mismatched types
+  --> $DIR/char-as-str-single.rs:18:9
+   |
+LL |     match c {
+   |           - this expression has type `char`
+LL |         "A" => {}
+   |         ^^^ expected `char`, found `&str`
+   |
+help: if you meant to write a `char` literal, use single quotes
+   |
+LL |         'A' => {}
+   |         ~~~
+
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0308`.