Don't suggest assoc ty bound on non-angle-bracketed problematic assoc ty binding

1 files changed, 16 insertions, 3 deletions

diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
index 9abae33ffdb..646ff3ca08d 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs
@@ -447,17 +447,30 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
     fn maybe_suggest_assoc_ty_bound(&self, self_ty: &hir::Ty<'_>, diag: &mut Diag<'_>) {
         let mut parents = self.tcx().hir_parent_iter(self_ty.hir_id);
 
-        if let Some((_, hir::Node::AssocItemConstraint(constraint))) = parents.next()
+        if let Some((c_hir_id, hir::Node::AssocItemConstraint(constraint))) = parents.next()
             && let Some(obj_ty) = constraint.ty()
+            && let Some((_, hir::Node::TraitRef(trait_ref))) = parents.next()
         {
-            if let Some((_, hir::Node::TraitRef(..))) = parents.next()
-                && let Some((_, hir::Node::Ty(ty))) = parents.next()
+            if let Some((_, hir::Node::Ty(ty))) = parents.next()
                 && let hir::TyKind::TraitObject(..) = ty.kind
             {
                 // Assoc ty bounds aren't permitted inside trait object types.
                 return;
             }
 
+            if trait_ref
+                .path
+                .segments
+                .iter()
+                .find_map(|seg| {
+                    seg.args.filter(|args| args.constraints.iter().any(|c| c.hir_id == c_hir_id))
+                })
+                .is_none_or(|args| args.parenthesized != hir::GenericArgsParentheses::No)
+            {
+                // Only consider angle-bracketed args (where we have a `=` to replace with `:`).
+                return;
+            }
+
             let lo = if constraint.gen_args.span_ext.is_dummy() {
                 constraint.ident.span
             } else {