1 files changed, 9 insertions, 5 deletions

diff --git a/crates/hir_def/src/path/lower.rs b/crates/hir_def/src/path/lower.rs
index 505493a74..7b29d9d4f 100644
--- a/crates/hir_def/src/path/lower.rs
+++ b/crates/hir_def/src/path/lower.rs
@@ -2,6 +2,7 @@
 
 mod lower_use;
 
+use crate::intern::Interned;
 use std::sync::Arc;
 
 use either::Either;
@@ -68,15 +69,17 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
                 match trait_ref {
                     // <T>::foo
                     None => {
-                        type_anchor = Some(Box::new(self_type));
+                        type_anchor = Some(Interned::new(self_type));
                         kind = PathKind::Plain;
                     }
                     // <T as Trait<A>>::Foo desugars to Trait<Self=T, A>::Foo
                     Some(trait_ref) => {
                         let path = Path::from_src(trait_ref.path()?, hygiene)?;
-                        kind = path.mod_path.kind;
+                        let mod_path = (*path.mod_path).clone();
+                        let num_segments = path.mod_path.segments.len();
+                        kind = mod_path.kind;
 
-                        let mut prefix_segments = path.mod_path.segments;
+                        let mut prefix_segments = mod_path.segments;
                         prefix_segments.reverse();
                         segments.extend(prefix_segments);
 
@@ -85,7 +88,8 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
                         generic_args.extend(prefix_args);
 
                         // Insert the type reference (T in the above example) as Self parameter for the trait
-                        let last_segment = generic_args.last_mut()?;
+                        let last_segment =
+                            generic_args.iter_mut().rev().nth(num_segments.saturating_sub(1))?;
                         if last_segment.is_none() {
                             *last_segment = Some(Arc::new(GenericArgs::empty()));
                         };
@@ -138,7 +142,7 @@ pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option<Path>
         }
     }
 
-    let mod_path = ModPath::from_segments(kind, segments);
+    let mod_path = Interned::new(ModPath::from_segments(kind, segments));
     return Some(Path { type_anchor, mod_path, generic_args });
 
     fn qualifier(path: &ast::Path) -> Option<ast::Path> {