rustdoc: always pass the owner of generic args

Author: fmease

src/librustdoc/clean/mod.rs

@@ -475,16 +475,17 @@ fn projection_to_path_segment<'tcx>(
     ty: ty::Binder<'tcx, ty::AliasTy<'tcx>>,
     cx: &mut DocContext<'tcx>,
 ) -> PathSegment {
-    let item = cx.tcx.associated_item(ty.skip_binder().def_id);
-    let generics = cx.tcx.generics_of(ty.skip_binder().def_id);
+    let def_id = ty.skip_binder().def_id;
+    let item = cx.tcx.associated_item(def_id);
+    let generics = cx.tcx.generics_of(def_id);
     PathSegment {
         name: item.name,
         args: GenericArgs::AngleBracketed {
             args: ty_args_to_args(
                 cx,
                 ty.map_bound(|ty| &ty.args[generics.parent_count..]),
                 false,
-                None,
+                def_id,
             )
             .into(),
             bindings: Default::default(),
@@ -2200,18 +2201,19 @@ pub(crate) fn clean_middle_ty<'tcx>(
         }
 
         ty::Alias(ty::Inherent, alias_ty) => {
+            let def_id = alias_ty.def_id;
             let alias_ty = bound_ty.rebind(alias_ty);
             let self_type = clean_middle_ty(alias_ty.map_bound(|ty| ty.self_ty()), cx, None, None);
 
             Type::QPath(Box::new(QPathData {
                 assoc: PathSegment {
-                    name: cx.tcx.associated_item(alias_ty.skip_binder().def_id).name,
+                    name: cx.tcx.associated_item(def_id).name,
                     args: GenericArgs::AngleBracketed {
                         args: ty_args_to_args(
                             cx,
                             alias_ty.map_bound(|ty| ty.args.as_slice()),
                             true,
-                            None,
+                            def_id,
                         )
                         .into(),
                         bindings: Default::default(),

src/librustdoc/clean/utils.rs

@@ -79,9 +79,9 @@ pub(crate) fn ty_args_to_args<'tcx>(
     cx: &mut DocContext<'tcx>,
     ty_args: ty::Binder<'tcx, &'tcx [ty::GenericArg<'tcx>]>,
     has_self: bool,
-    container: Option<DefId>,
+    owner: DefId,
 ) -> Vec<GenericArg> {
-    let params = container.map(|container| &cx.tcx.generics_of(container).params);
+    let params = &cx.tcx.generics_of(owner).params;
     let mut elision_has_failed_once_before = false;
 
     let offset = if has_self { 1 } else { 0 };
@@ -94,7 +94,6 @@ pub(crate) fn ty_args_to_args<'tcx>(
         GenericArgKind::Type(_) if has_self && index == 0 => None,
         GenericArgKind::Type(ty) => {
             if !elision_has_failed_once_before
-                && let Some(params) = params
                 && let Some(default) = params[index].default_value(cx.tcx)
             {
                 let default =
@@ -111,8 +110,8 @@ pub(crate) fn ty_args_to_args<'tcx>(
                 ty_args.rebind(ty),
                 cx,
                 None,
-                container.map(|container| crate::clean::ContainerTy::Regular {
-                    ty: container,
+                Some(crate::clean::ContainerTy::Regular {
+                    ty: owner,
                     args: ty_args,
                     has_self,
                     arg: index,
@@ -130,7 +129,6 @@ pub(crate) fn ty_args_to_args<'tcx>(
             }
 
             if !elision_has_failed_once_before
-                && let Some(params) = params
                 && let Some(default) = params[index].default_value(cx.tcx)
             {
                 let default =
@@ -200,7 +198,7 @@ fn external_generic_args<'tcx>(
     bindings: ThinVec<TypeBinding>,
     ty_args: ty::Binder<'tcx, GenericArgsRef<'tcx>>,
 ) -> GenericArgs {
-    let args = ty_args_to_args(cx, ty_args.map_bound(|args| &args[..]), has_self, Some(did));
+    let args = ty_args_to_args(cx, ty_args.map_bound(|args| &args[..]), has_self, did);
 
     if cx.tcx.fn_trait_kind_from_def_id(did).is_some() {
         let ty = ty_args