project_search: Guard replace_next match lookup (#48327)

Release Notes:

- N/A

Signed-off-by: Xiaobo Liu <cppcoffee@gmail.com>

crates/search/src/project_search.rs

@@ -728,10 +728,11 @@ impl ProjectSearchView {
         if let Some(query) = query {
             let query = query.with_replacement(self.replacement(cx));
 
-            // TODO: Do we need the clone here?
-            let mat = self.entity.read(cx).match_ranges[active_index].clone();
+            let mat = self.entity.read(cx).match_ranges.get(active_index).cloned();
             self.results_editor.update(cx, |editor, cx| {
-                editor.replace(&mat, &query, window, cx);
+                if let Some(mat) = mat.as_ref() {
+                    editor.replace(mat, &query, window, cx);
+                }
             });
             self.select_match(Direction::Next, window, cx)
         }