Syntax error while parsing object key (pdf with Chinese characters)

[danielkorzekwa]

Bug

Converting a pdf with Chinese characters fails with "syntax error while parsing object key" exception

...
ArxivService.extract_text_from_pdf(self, arxiv_id)
41 source = self._get_pdf_filepath(arxiv_id)
42 converter = DocumentConverter()
---> 43 result = converter.convert(source)
44 pdf_text = result.document.export_to_markdown()
...
miniconda3/envs/bfs/lib/python3.12/site-packages/docling/backend/docling_parse_backend.py#line=24), in DoclingParsePageBackend.init(self, parser, document_hash, page_no, page_obj)
21 def init(
22 self, parser: pdf_parser_v1, document_hash: str, page_no: int, page_obj: PdfPage
23 ):
24 self._ppage = page_obj
---> 25 parsed_page = parser.parse_pdf_from_key_on_page(document_hash, page_no)
27 self.valid = "pages" in parsed_page
28 if self.valid:

RuntimeError: [json.exception.parse_error.101] parse error at line 13, column 36: syntax error while parsing object key - invalid string: control character U+001F (US) must be escaped to \u001F; last read: '"/PVOXJK+FlexiFontBZ?<U+001F>'; expected string literal
https://arxiv.org/pdf/2410.06488

Steps to reproduce

Parse this pdf:
https://arxiv.org/pdf/2410.06488

Docling version

pip list |grep docling
docling 2.4.2
docling-core 2.3.1
docling-ibm-models 2.0.3
docling-parse 2.0.3

Python version

Python 3.12.4