Fix `findall` usage in KeyboardTransform

1 files changed, 5 insertions, 1 deletions

diff --git a/sphinx/builders/html/transforms.py b/sphinx/builders/html/transforms.py
index ea596cb4b..7f96c4e60 100644
--- a/sphinx/builders/html/transforms.py
+++ b/sphinx/builders/html/transforms.py
@@ -40,7 +40,10 @@ class KeyboardTransform(SphinxPostTransform):
 
     def run(self, **kwargs: Any) -> None:
         matcher = NodeMatcher(nodes.literal, classes=["kbd"])
-        for node in self.document.findall(matcher):  # type: nodes.literal
+        # this list must be pre-created as during iteration new nodes
+        # are added which match the condition in the NodeMatcher.
+        nodes_to_expand = list(self.document.findall(matcher))
+        for node in nodes_to_expand:  # type: nodes.literal
             parts = self.pattern.split(node[-1].astext())
             if len(parts) == 1 or self.is_multiwords_key(parts):
                 continue
@@ -61,6 +64,7 @@ class KeyboardTransform(SphinxPostTransform):
                     node += nodes.Text(sep)
                 except IndexError:
                     pass
+                _a = 1
 
     def is_multiwords_key(self, parts: List[str]) -> bool:
         if len(parts) >= 3 and parts[1].strip() == '':