Handle numbering levels defined without an index

1 files changed, 6 insertions, 0 deletions

diff --git a/mammoth/docx/body_xml.py b/mammoth/docx/body_xml.py
index d3dd267..e2a490a 100644
--- a/mammoth/docx/body_xml.py
+++ b/mammoth/docx/body_xml.py
@@ -288,6 +288,12 @@ def _create_reader(numbering, content_types, relationships, styles, docx_file, f
             if level is not None:
                 return level
 
+        # Some malformed documents define numbering levels without an index, and
+        # reference the numbering using a w:numPr element without a w:ilvl child.
+        # To handle such cases, we assume a level of 0 as a fallback.
+        if num_id is not None:
+            return numbering.find_level(num_id, "0")
+
         return None
 
     def _read_paragraph_indent(element):