Fix syntax_editor duplicated changed tokens

Author: A4-Tacks

src/tools/rust-analyzer/crates/syntax/src/syntax_editor.rs

@@ -654,6 +654,24 @@ mod tests {
         expect.assert_eq(&edit.new_root.to_string());
     }
 
+    #[test]
+    fn test_more_times_replace_node_to_mutable_token() {
+        let arg_list =
+            make::arg_list([make::expr_literal("1").into(), make::expr_literal("2").into()]);
+
+        let mut editor = SyntaxEditor::new(arg_list.syntax().clone());
+        let target_expr = make::token(parser::SyntaxKind::UNDERSCORE);
+
+        for arg in arg_list.args() {
+            editor.replace(arg.syntax(), &target_expr);
+        }
+
+        let edit = editor.finish();
+
+        let expect = expect![["(_, _)"]];
+        expect.assert_eq(&edit.new_root.to_string());
+    }
+
     #[test]
     fn test_more_times_replace_node_to_mutable() {
         let arg_list =

src/tools/rust-analyzer/crates/syntax/src/syntax_editor/edit_algo.rs

@@ -152,9 +152,29 @@ pub(super) fn apply_edits(editor: SyntaxEditor) -> SyntaxEdit {
     let mut changed_elements = vec![];
     let mut changed_elements_set = rustc_hash::FxHashSet::default();
     let mut deduplicate_node = |node_or_token: &mut SyntaxElement| {
-        let SyntaxElement::Node(node) = node_or_token else { return };
+        let node;
+        let node = match node_or_token {
+            SyntaxElement::Token(token) => match token.parent() {
+                None => return,
+                Some(parent) => {
+                    node = parent;
+                    &node
+                }
+            },
+            SyntaxElement::Node(node) => node,
+        };
         if changed_elements_set.contains(node) {
-            *node = node.clone_subtree().clone_for_update();
+            let new_node = node.clone_subtree().clone_for_update();
+            match node_or_token {
+                SyntaxElement::Node(node) => *node = new_node,
+                SyntaxElement::Token(token) => {
+                    *token = new_node
+                        .children_with_tokens()
+                        .filter_map(SyntaxElement::into_token)
+                        .find(|it| it.kind() == token.kind() && it.text() == token.text())
+                        .unwrap();
+                }
+            }
         } else {
             changed_elements_set.insert(node.clone());
         }