display correctly 'impl Trait<T> + Trait<T>' #4814

Signed-off-by: Benjamin Coenen <5719034+bnjjj@users.noreply.github.com>

crates/hir_ty/src/display.rs

@@ -511,6 +511,7 @@ fn write_bounds_like_dyn_trait(
             GenericPredicate::Implemented(trait_ref) => {
                 if angle_open {
                     write!(f, ">")?;
+                    angle_open = false;
                 }
                 if !first {
                     write!(f, " + ")?;

crates/ide/src/hover.rs

@@ -766,6 +766,25 @@ fn main() {
         )
     }
 
+    #[test]
+    fn hover_for_param_with_multiple_traits() {
+        check(
+            r#"trait Deref {
+                type Target: ?Sized;
+            }
+            trait DerefMut {
+                type Target: ?Sized;
+            }
+            fn f(_x<|>: impl Deref<Target=u8> + DerefMut<Target=u8>) {}"#,
+            expect![[r#"
+                *_x*
+                ```rust
+                impl Deref<Target = u8> + DerefMut<Target = u8>
+                ```
+            "#]],
+        )
+    }
+
     #[test]
     fn test_hover_infer_associated_method_result() {
         check(