fix(asciidoc): stop a dedented list from crashing the backend

docling/backend/asciidoc_backend.py

@@ -153,7 +153,7 @@ def _parse(self, doc: DoclingDocument):
 
                 elif in_list and item["indent"] < indents[level]:
                     # print(item["indent"], " => ", indents[level])
-                    while item["indent"] < indents[level]:
+                    while level > 0 and item["indent"] < indents[level]:
                         # print(item["indent"], " => ", indents[level])
                         parents[level] = None
                         indents[level] = None

tests/test_backend_asciidoc.py

@@ -1,4 +1,5 @@
 import glob
+from io import BytesIO
 from pathlib import Path
 
 from docling.backend.asciidoc_backend import (
@@ -24,6 +25,23 @@ def _get_backend(fname):
     return doc_backend
 
 
+def test_list_dedent_to_base_does_not_crash():
+    # A list that starts indented and then dedents back to the base level used
+    # to raise "TypeError: '<' not supported between instances of 'int' and
+    # 'NoneType'": the dedent loop walked past level 0, where the base indent is
+    # never set. It should keep both items instead.
+    src = b"  * a\n* b\n"
+    in_doc = InputDocument(
+        path_or_stream=BytesIO(src),
+        format=InputFormat.ASCIIDOC,
+        backend=AsciiDocBackend,
+        filename="dedent.asciidoc",
+    )
+    doc = in_doc._backend.convert()
+
+    assert [item.text for item in doc.texts] == ["a", "b"]
+
+
 def test_parse_picture():
     line = (
         "image::images/example1.png[Example Image, width=200, height=150, align=center]"