Narrow the find/replace of showZeros

Author: afourney

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

@@ -1,4 +1,5 @@
 import io
+import re
 import sys
 import zipfile
 from typing import BinaryIO, Any
@@ -35,19 +36,36 @@
 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)
+        repaired_stream = _repair_sheetview_show_zeroes(file_stream, start_pos)
         return pd.read_excel(repaired_stream, sheet_name=None, engine="openpyxl")
 
 
-def _repair_sheetview_show_zeroes(file_stream: BinaryIO) -> io.BytesIO:
-    file_stream.seek(0)
+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:
@@ -57,8 +75,9 @@ def _repair_sheetview_show_zeroes(file_stream: BinaryIO) -> io.BytesIO:
                 if (
                     item.filename.startswith("xl/worksheets/")
                     and item.filename.endswith(".xml")
+                    and b"showZeroes" in data
                 ):
-                    data = data.replace(b" showZeroes=", b" showZeros=")
+                    data = _rename_show_zeroes_attribute(data)
                 target.writestr(item, data)
 
     repaired_stream.seek(0)

packages/markitdown/tests/test_module_misc.py

@@ -385,6 +385,9 @@ def test_xlsx_legacy_show_zeroes_sheetview(tmp_path) -> None:
     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:
@@ -395,7 +398,9 @@ def test_xlsx_legacy_show_zeroes_sheetview(tmp_path) -> None:
                     data = data.replace(
                         b"<sheetView ", b'<sheetView showZeroes="0" ', 1
                     )
-                    assert b"showZeroes" in data
+                    # 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))
@@ -404,6 +409,41 @@ def test_xlsx_legacy_show_zeroes_sheetview(tmp_path) -> None:
     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()