make ast::UseTree::wrap_in_tree_list more robust

Author: davidsemakula

crates/syntax/src/ast/edit_in_place.rs

@@ -538,16 +538,21 @@ impl ast::UseTree {
     /// `foo::bar` -> `{foo::bar}`
     ///
     /// `{foo::bar}` -> `{foo::bar}`
-    pub fn wrap_in_tree_list(&self) {
-        if self.path().is_none() {
-            return;
+    pub fn wrap_in_tree_list(&self) -> Option<()> {
+        if self.use_tree_list().is_some()
+            && self.path().is_none()
+            && self.star_token().is_none()
+            && self.rename().is_none()
+        {
+            return None;
         }
         let subtree = self.clone_subtree().clone_for_update();
         ted::remove_all_iter(self.syntax().children_with_tokens());
         ted::append_child(
             self.syntax(),
             make::use_tree_list(once(subtree)).clone_for_update().syntax(),
         );
+        Some(())
     }
 }