3 files changed, 33 insertions, 8 deletions
diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs
index afac6fc6004..68fe90f0de2 100644
--- a/compiler/rustc_trait_selection/src/errors.rs
+++ b/compiler/rustc_trait_selection/src/errors.rs
@@ -10,7 +10,7 @@ use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{Visitor, walk_ty};
-use rustc_hir::{FnRetTy, GenericParamKind};
+use rustc_hir::{FnRetTy, GenericParamKind, Node};
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_middle::ty::print::{PrintTraitRefExt as _, TraitRefPrintOnlyTraitPath};
 use rustc_middle::ty::{self, Binder, ClosureKind, FnSig, PolyTraitRef, Region, Ty, TyCtxt};
@@ -1888,10 +1888,35 @@ pub fn impl_trait_overcapture_suggestion<'tcx>(
         .collect::<Vec<_>>()
         .join(", ");
 
-    suggs.push((
-        tcx.def_span(opaque_def_id).shrink_to_hi(),
-        format!(" + use<{concatenated_bounds}>"),
-    ));
+    let opaque_hir_id = tcx.local_def_id_to_hir_id(opaque_def_id);
+    // FIXME: This is a bit too conservative, since it ignores parens already written in AST.
+    let (lparen, rparen) = match tcx
+        .hir()
+        .parent_iter(opaque_hir_id)
+        .nth(1)
+        .expect("expected ty to have a parent always")
+        .1
+    {
+        Node::PathSegment(segment)
+            if segment.args().paren_sugar_output().is_some_and(|ty| ty.hir_id == opaque_hir_id) =>
+        {
+            ("(", ")")
+        }
+        Node::Ty(ty) => match ty.kind {
+            rustc_hir::TyKind::Ptr(_) | rustc_hir::TyKind::Ref(..) => ("(", ")"),
+            // FIXME: RPITs are not allowed to be nested in `impl Fn() -> ...`,
+            // but we eventually could support that, and that would necessitate
+            // making this more sophisticated.
+            _ => ("", ""),
+        },
+        _ => ("", ""),
+    };
+
+    let rpit_span = tcx.def_span(opaque_def_id);
+    if !lparen.is_empty() {
+        suggs.push((rpit_span.shrink_to_lo(), lparen.to_string()));
+    }
+    suggs.push((rpit_span.shrink_to_hi(), format!(" + use<{concatenated_bounds}>{rparen}")));
 
     Some(AddPreciseCapturingForOvercapture { suggs, apit_spans })
 }
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 49c34550f8e..541c0c915ff 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -744,7 +744,7 @@ fn assemble_candidates_from_trait_def<'cx, 'tcx>(
             let Some(clause) = clause.as_projection_clause() else {
                 return ControlFlow::Continue(());
             };
-            if clause.projection_def_id() != obligation.predicate.def_id {
+            if clause.item_def_id() != obligation.predicate.def_id {
                 return ControlFlow::Continue(());
             }
 
@@ -847,7 +847,7 @@ fn assemble_candidates_from_predicates<'cx, 'tcx>(
         let bound_predicate = predicate.kind();
         if let ty::ClauseKind::Projection(data) = predicate.kind().skip_binder() {
             let data = bound_predicate.rebind(data);
-            if data.projection_def_id() != obligation.predicate.def_id {
+            if data.item_def_id() != obligation.predicate.def_id {
                 continue;
             }
 
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index d362866cbc3..25fe43e3a0e 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -1737,7 +1737,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         env_predicate: PolyProjectionPredicate<'tcx>,
         potentially_unnormalized_candidates: bool,
     ) -> ProjectionMatchesProjection {
-        debug_assert_eq!(obligation.predicate.def_id, env_predicate.projection_def_id());
+        debug_assert_eq!(obligation.predicate.def_id, env_predicate.item_def_id());
 
         let mut nested_obligations = PredicateObligations::new();
         let infer_predicate = self.infcx.instantiate_binder_with_fresh_vars(