fix(xlsx): tolerate legacy showZeroes sheet views (#2064)

* fix(xlsx): tolerate legacy showZeroes sheet views

* Narrow the find/replace of showZeros

---------

Co-authored-by: afourney <adamfo@microsoft.com>

Author: he-yufeng

packages/markitdown/src/markitdown/converters/_xlsx_converter.py

@@ -1,4 +1,7 @@
+import io
+import re
 import sys
+import zipfile
 from typing import BinaryIO, Any
 from ._html_converter import HtmlConverter
 from .._base_converter import DocumentConverter, DocumentConverterResult
@@ -33,6 +36,54 @@
 ACCEPTED_XLS_FILE_EXTENSIONS = [".xls"]
 
 
+# Some producers write the legacy attribute "showZeroes" on <sheetView>, where the
+# schema calls it "showZeros". openpyxl rejects the unknown attribute outright, so the
+# workbook is repaired by renaming it. The rename is confined to <sheetView> start tags.
+_SHEET_VIEW_START_TAG = re.compile(rb"<sheetView(?=[\s/>])[^>]*>")
+_SHOW_ZEROES_ATTRIBUTE = re.compile(rb"(?<=[\s])showZeroes(\s*=)")
+
+
+def _read_xlsx_sheets(file_stream: BinaryIO) -> dict[str, Any]:
+    start_pos = file_stream.tell()
+    try:
+        return pd.read_excel(file_stream, sheet_name=None, engine="openpyxl")
+    except TypeError as exc:
+        if "showZeroes" not in str(exc):
+            raise
+
+        repaired_stream = _repair_sheetview_show_zeroes(file_stream, start_pos)
+        return pd.read_excel(repaired_stream, sheet_name=None, engine="openpyxl")
+
+
+def _rename_show_zeroes_attribute(data: bytes) -> bytes:
+    return _SHEET_VIEW_START_TAG.sub(
+        lambda match: _SHOW_ZEROES_ATTRIBUTE.sub(rb"showZeros\1", match.group(0)),
+        data,
+    )
+
+
+def _repair_sheetview_show_zeroes(
+    file_stream: BinaryIO, start_pos: int = 0
+) -> io.BytesIO:
+    file_stream.seek(start_pos)
+    repaired_stream = io.BytesIO()
+
+    with zipfile.ZipFile(file_stream) as source:
+        with zipfile.ZipFile(repaired_stream, "w", zipfile.ZIP_DEFLATED) as target:
+            for item in source.infolist():
+                data = source.read(item.filename)
+                if (
+                    item.filename.startswith("xl/worksheets/")
+                    and item.filename.endswith(".xml")
+                    and b"showZeroes" in data
+                ):
+                    data = _rename_show_zeroes_attribute(data)
+                target.writestr(item, data)
+
+    repaired_stream.seek(0)
+    return repaired_stream
+
+
 class XlsxConverter(DocumentConverter):
     """
     Converts XLSX files to Markdown, with each sheet presented as a separate Markdown table.
@@ -80,7 +131,7 @@ def convert(
                 _xlsx_dependency_exc_info[2]
             )
 
-        sheets = pd.read_excel(file_stream, sheet_name=None, engine="openpyxl")
+        sheets = _read_xlsx_sheets(file_stream)
         md_content = ""
         for s in sheets:
             md_content += f"## {s}\n"

packages/markitdown/tests/test_module_misc.py

@@ -6,8 +6,8 @@
 import re
 import shutil
 import zipfile
-from types import SimpleNamespace
 import pytest
+from types import SimpleNamespace
 from unittest.mock import MagicMock
 
 import markitdown._uri_utils as uri_utils
@@ -374,6 +374,77 @@ def test_docx_equations() -> None:
     assert block_equations, "No block equations found in the document."
 
 
+def test_xlsx_legacy_show_zeroes_sheetview(tmp_path) -> None:
+    from openpyxl import Workbook
+
+    base_path = tmp_path / "base.xlsx"
+    xlsx_path = tmp_path / "legacy_show_zeroes.xlsx"
+
+    workbook = Workbook()
+    sheet = workbook.active
+    sheet.title = "Data"
+    sheet["A1"] = "hello"
+    sheet["B1"] = "world"
+    # A cell whose text is byte-identical to the malformed attribute. openpyxl stores it
+    # as an inline string, so it lands in the very worksheet part that gets repaired.
+    sheet["A2"] = ' showZeroes="0" '
+    workbook.save(base_path)
+
+    with zipfile.ZipFile(base_path) as source:
+        with zipfile.ZipFile(xlsx_path, "w", zipfile.ZIP_DEFLATED) as target:
+            for item in source.infolist():
+                data = source.read(item.filename)
+                if item.filename == "xl/worksheets/sheet1.xml":
+                    data = data.replace(
+                        b"<sheetView ", b'<sheetView showZeroes="0" ', 1
+                    )
+                    # Guard the fixture: the sheet view attribute and the cell text must
+                    # both live here, or this test stops exercising the repair.
+                    assert data.count(b'showZeroes="0"') == 2
+                target.writestr(item, data)
+
+    result = MarkItDown().convert(str(xlsx_path))
+
+    assert "## Data" in result.markdown
+    assert "hello" in result.markdown
+    assert "world" in result.markdown
+
+    # The repair must not reach into the worksheet's data: the cell keeps its text ...
+    assert 'showZeroes="0"' in result.markdown
+    # ... and no part of the document was silently renamed on the way through.
+    assert "showZeros" not in result.markdown
+
+
+def test_xlsx_show_zeroes_rename_is_scoped_to_sheet_view_tags() -> None:
+    from markitdown.converters._xlsx_converter import _rename_show_zeroes_attribute
+
+    worksheet_xml = (
+        b"<worksheet><sheetViews>"
+        b'<sheetView showZeroes="0" workbookViewId="0"/>'
+        b'<sheetView\n\tshowZeroes="1"\ttabSelected="1"/>'
+        b"</sheetViews>"
+        # openpyxl ignores custom sheet views entirely, so they need no repair
+        b'<customSheetViews><customSheetView showZeroes="0"/></customSheetViews>'
+        b'<sheetData><row r="1">'
+        b'<c r="A1" t="inlineStr"><is><t xml:space="preserve"> showZeroes="0" '
+        b"</t></is></c>"
+        b'<c r="B1"><f>IF(A1=" showZeroes=","x","y")</f><v>y</v></c>'
+        b"</row></sheetData></worksheet>"
+    )
+
+    repaired = _rename_show_zeroes_attribute(worksheet_xml)
+
+    # Every <sheetView> start tag is repaired, whatever separates its attributes ...
+    assert repaired.count(b"showZeros=") == 2
+    assert b'<sheetView showZeros="0" workbookViewId="0"/>' in repaired
+    assert b'<sheetView\n\tshowZeros="1"\ttabSelected="1"/>' in repaired
+
+    # ... and nothing outside those start tags is rewritten.
+    assert b'<t xml:space="preserve"> showZeroes="0" </t>' in repaired
+    assert b'<f>IF(A1=" showZeroes=","x","y")</f>' in repaired
+    assert b'<customSheetView showZeroes="0"/>' in repaired
+
+
 def test_input_as_strings() -> None:
     markitdown = MarkItDown()