From 04b79785c2e56c11365ec45a6d8f1609294f6b20 Mon Sep 17 00:00:00 2001
From: chrikrah <48338417+chrikrah@users.noreply.github.com>
Date: Sat, 26 Sep 2026 09:30:57 +0000
Subject: [PATCH] fix(pptx): keep the document when a 3-D area chart has no
 series class

python-pptx registers both an element class and a plot class for
`c:area3DChart`, but no series class, so reading its series raises
`NotImplementedError`. The other 3-D plots raise `ValueError` or
`AttributeError` from `chart.chart_type`, which the guard above already
catches, so `c:area3DChart` was the one chart type whose failure escaped
`_handle_chart` and aborted the conversion of the whole presentation.

Catch it where the other failures are caught, so the chart degrades to a
classified picture without tabular data, exactly as `c:bar3DChart` does.

Signed-off-by: chrikrah <48338417+chrikrah@users.noreply.github.com>
---
 docling/backend/mspowerpoint_backend.py |  6 ++-
 tests/test_backend_pptx.py              | 50 +++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/docling/backend/mspowerpoint_backend.py b/docling/backend/mspowerpoint_backend.py
index 1bbc75ec89..b01940d335 100644
--- a/docling/backend/mspowerpoint_backend.py
+++ b/docling/backend/mspowerpoint_backend.py
@@ -1153,7 +1153,11 @@ def _handle_chart(self, shape, parent_slide, slide_ind, doc, slide_size):
         caption_text = self._chart_title_text(chart)
         try:
             table_data = self._chart_to_table_data(chart)
-        except (AttributeError, ValueError, KeyError) as exc:
+        except (AttributeError, ValueError, KeyError, NotImplementedError) as exc:
+            # NotImplementedError: python-pptx registers an element class and a
+            # plot class for c:area3DChart but no series class, so reading its
+            # series raises where every other 3-D plot raises earlier and is
+            # already caught above.
             _log.warning("Could not extract chart data: %s", exc)
             table_data = None
 
diff --git a/tests/test_backend_pptx.py b/tests/test_backend_pptx.py
index b6a08e4973..a63b6f5a07 100644
--- a/tests/test_backend_pptx.py
+++ b/tests/test_backend_pptx.py
@@ -4,6 +4,7 @@
 import logging
 import struct
 import warnings
+import zipfile
 import zlib
 from collections.abc import Iterable
 from pathlib import Path
@@ -448,6 +449,55 @@ def test_chart_image_rendering(libreoffice_available):
     )
 
 
+def test_area_3d_chart_degrades_instead_of_failing_the_document(tmp_path: Path):
+    """A ``c:area3DChart`` must lose only its data, not the whole presentation.
+
+    python-pptx has no series class for a 3-D area chart, so reading its series
+    raises ``NotImplementedError``. Every other 3-D plot raises earlier, where
+    it is already caught, so this one chart aborted the conversion of the entire
+    deck. It should degrade the way ``c:bar3DChart`` does: a classified picture
+    with no tabular data.
+    """
+    from pptx import Presentation
+    from pptx.chart.data import CategoryChartData
+    from pptx.enum.chart import XL_CHART_TYPE
+    from pptx.util import Inches
+
+    prs = Presentation()
+    slide = prs.slides.add_slide(prs.slide_layouts[6])
+    chart_data = CategoryChartData()
+    chart_data.categories = ["Q1", "Q2"]
+    chart_data.add_series("Revenue", (10.0, 20.0))
+    slide.shapes.add_chart(
+        XL_CHART_TYPE.AREA, Inches(1), Inches(1), Inches(4), Inches(3), chart_data
+    )
+    slide.shapes.add_textbox(
+        Inches(0.2), Inches(0.2), Inches(3), Inches(0.5)
+    ).text_frame.text = "text beside the chart"
+    flat = tmp_path / "area2d.pptx"
+    prs.save(flat)
+
+    # python-pptx cannot write a 3-D area chart, so retag the plot element the
+    # way PowerPoint writes one.
+    source = tmp_path / "area3d.pptx"
+    with (
+        zipfile.ZipFile(flat) as original,
+        zipfile.ZipFile(source, "w", zipfile.ZIP_DEFLATED) as retagged,
+    ):
+        for info in original.infolist():
+            payload = original.read(info.filename)
+            if info.filename == "ppt/charts/chart1.xml":
+                payload = payload.replace(b"c:areaChart", b"c:area3DChart")
+            retagged.writestr(info, payload)
+
+    doc = get_converter().convert(source).document
+
+    pictures = list(doc.pictures)
+    assert len(pictures) == 1
+    assert pictures[0].meta.tabular_chart is None
+    assert "text beside the chart" in doc.export_to_markdown()
+
+
 def _add_bar_chart(shapes):
     """Add a small bar chart to a slide or group shape tree."""
     from pptx.chart.data import CategoryChartData