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fix: gracefully handle invalide html string during chunking#4243

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badGarnet merged 7 commits intomainfrom
fix/gracefully-handle-invalid-html-string
Feb 18, 2026
Merged

fix: gracefully handle invalide html string during chunking#4243
badGarnet merged 7 commits intomainfrom
fix/gracefully-handle-invalid-html-string

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@badGarnet badGarnet commented Feb 18, 2026

This PR fixes an issue where an invalid text_as_html input into html based table chunking logic can lead to chunking failing. Like the following stack trace shows:

    |   File "/app/unstructured/unstructured/chunking/base.py", line 594, in iter_chunks
    |     yield from _TableChunker.iter_chunks(
    |   File "/app/unstructured/unstructured/chunking/base.py", line 837, in _iter_chunks
    |     html_size = measure(self._html) if self._html else 0
    |                                        ^^^^^^^^^^
    |   File "/app/unstructured/unstructured/utils.py", line 154, in __get__
    |     value = self._fget(obj)
    |             ^^^^^^^^^^^^^^^
    |   File "/app/unstructured/unstructured/chunking/base.py", line 866, in _html
    |     if not (html_table := self._html_table):
    |                           ^^^^^^^^^^^^^^^^
    |   File "/app/unstructured/unstructured/utils.py", line 154, in __get__
    |     value = self._fget(obj)
    |             ^^^^^^^^^^^^^^^
    |   File "/app/unstructured/unstructured/chunking/base.py", line 884, in _html_table
    |     return HtmlTable.from_html_text(text_as_html)
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |   File "/app/unstructured/unstructured/common/html_table.py", line 61, in from_html_text
    |     root = fragment_fromstring(html_text)
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |   File "/app/.venv/lib/python3.12/site-packages/lxml/html/__init__.py", line 810, in fragment_fromstring
    |     elements = fragments_fromstring(
    |                ^^^^^^^^^^^^^^^^^^^^^
    |   File "/app/.venv/lib/python3.12/site-packages/lxml/html/__init__.py", line 780, in fragments_fromstring
    |     raise etree.ParserError(
    | lxml.etree.ParserError: There is leading text: '```html\n'

The solution is to catch the parser error and return a None instead in unstructured/chunking/base.py in _html_table. This way we fallback to text based chunking for this element with a warning log.

@badGarnet badGarnet marked this pull request as ready for review February 18, 2026 04:00
PastelStorm
PastelStorm reviewed Feb 18, 2026
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unstructured/chunking/base.py Outdated
return HtmlTable.from_html_text(text_as_html)
try:
return HtmlTable.from_html_text(text_as_html)
except ParserError:
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@PastelStorm PastelStorm Feb 18, 2026

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We should also catch ValueError here and a test to cover this new path.

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socket-security bot commented Feb 18, 2026

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

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Addedgithub/​docker/​setup-compose-action@​364cc21a5de5b1ee4a7f5f9d3fa374ce0ccde74699100100100100

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@badGarnet badGarnet added this pull request to the merge queue Feb 18, 2026
Merged via the queue into main with commit c1f819c Feb 18, 2026
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@badGarnet badGarnet deleted the fix/gracefully-handle-invalid-html-string branch February 18, 2026 20:08
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