Suppress ValueError in apply_source_workaround (#11092)

CHANGES

@@ -16,6 +16,9 @@ Features added
 Bugs fixed
 ----------
 
+* #11091: Fix ``util.nodes.apply_source_workaround`` for ``literal_block`` nodes
+  with no source information in the node or the node's parents.
+
 Testing
 --------
 

sphinx/util/nodes.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import contextlib
 import re
 import unicodedata
 from typing import TYPE_CHECKING, Any, Callable, Iterable
@@ -152,7 +153,8 @@ def apply_source_workaround(node: Element) -> None:
 
     # workaround: literal_block under bullet list (#4913)
     if isinstance(node, nodes.literal_block) and node.source is None:
-        node.source = get_node_source(node)
+        with contextlib.suppress(ValueError):
+            node.source = get_node_source(node)
 
     # workaround: recommonmark-0.2.0 doesn't set rawsource attribute
     if not node.rawsource:

tests/test_util_nodes.py

@@ -11,8 +11,8 @@
 from docutils.utils import new_document
 
 from sphinx.transforms import ApplySourceWorkaround
-from sphinx.util.nodes import (NodeMatcher, clean_astext, extract_messages, make_id,
-                               split_explicit_title)
+from sphinx.util.nodes import (NodeMatcher, apply_source_workaround, clean_astext,
+                               extract_messages, make_id, split_explicit_title)
 
 
 def _transform(doctree):
@@ -226,3 +226,23 @@ def test_make_id_sequential(app):
 )
 def test_split_explicit_target(title, expected):
     assert expected == split_explicit_title(title)
+
+
+def test_apply_source_workaround_literal_block_no_source():
+    """Regression test for #11091.
+
+     Test that apply_source_workaround doesn't raise.
+     """
+    literal_block = nodes.literal_block('', '')
+    list_item = nodes.list_item('', literal_block)
+    bullet_list = nodes.bullet_list('', list_item)
+
+    assert literal_block.source is None
+    assert list_item.source is None
+    assert bullet_list.source is None
+
+    apply_source_workaround(literal_block)
+
+    assert literal_block.source is None
+    assert list_item.source is None
+    assert bullet_list.source is None