Support docutils-0.18: Consume iterator of Element.traverse()

Since 0.18, Element.traverse() returns an iterator instead of
intermediate object.  As a result, the return value is always considered
as truthy value.  And it becomes fragile when the caller modifies the
doctree on the loop.

1 files changed, 1 insertions, 1 deletions

diff --git a/sphinx/ext/todo.py b/sphinx/ext/todo.py
index 6b7c1b73b..beab0976d 100644
--- a/sphinx/ext/todo.py
+++ b/sphinx/ext/todo.py
@@ -131,7 +131,7 @@ class TodoListProcessor:
 
     def process(self, doctree: nodes.document, docname: str) -> None:
         todos: List[todo_node] = sum(self.domain.todos.values(), [])
-        for node in doctree.traverse(todolist):
+        for node in list(doctree.traverse(todolist)):
             if not self.config.todo_include_todos:
                 node.parent.remove(node)
                 continue