fix(pptx): handle NotImplementedError from shape.shape_type (#3309)

* fix(pptx): handle NotImplementedError from shape.shape_type

python-pptx raises NotImplementedError from Shape.shape_type for
<p:sp> elements that aren't placeholders, autoshapes, textboxes, or
freeforms (e.g. shapes with empty <p:spPr> from Google Slides exports,
LibreOffice, or Keynote). handle_groups() and handle_shapes() access
shape_type without catching this, crashing the entire conversion.

Add a _safe_shape_type() helper that returns None on
NotImplementedError, so unrecognized shapes skip only the GROUP
recursion and PICTURE extraction while text and table extraction
proceed normally.

Fixes #3308

Signed-off-by: Tejas Patel <tejas226@hotmail.com>

* Fix lint

Signed-off-by: Tejas Patel <tejas226@hotmail.com>

---------

Signed-off-by: Tejas Patel <tejas226@hotmail.com>

Author: pateltejas

docling/backend/mspowerpoint_backend.py

@@ -688,12 +688,25 @@ def _walk_linear(
             slide_size = Size(width=slide_width, height=slide_height)
             doc.add_page(page_no=slide_ind + 1, size=slide_size)
 
+            def _safe_shape_type(shape):
+                """Return shape.shape_type, or None if unrecognized.
+
+                python-pptx raises NotImplementedError for <p:sp> elements
+                that don't match any known shape category (placeholder,
+                freeform, autoshape, textbox).
+                """
+                try:
+                    return shape.shape_type
+                except NotImplementedError:
+                    _log.debug("Skipping shape with unrecognized type: %s", shape.name)
+                    return None
+
             def handle_shapes(shape, parent_slide, slide_ind, doc, slide_size):
                 handle_groups(shape, parent_slide, slide_ind, doc, slide_size)
                 if shape.has_table:
                     # Handle Tables
                     self._handle_tables(shape, parent_slide, slide_ind, doc, slide_size)
-                if shape.shape_type == MSO_SHAPE_TYPE.PICTURE:
+                if _safe_shape_type(shape) == MSO_SHAPE_TYPE.PICTURE:
                     # Handle Pictures
                     self._handle_pictures(
                         shape, parent_slide, slide_ind, doc, slide_size
@@ -716,7 +729,7 @@ def handle_shapes(shape, parent_slide, slide_ind, doc, slide_size):
                 return
 
             def handle_groups(shape, parent_slide, slide_ind, doc, slide_size):
-                if shape.shape_type == MSO_SHAPE_TYPE.GROUP:
+                if _safe_shape_type(shape) == MSO_SHAPE_TYPE.GROUP:
                     for groupedshape in shape.shapes:
                         handle_shapes(
                             groupedshape, parent_slide, slide_ind, doc, slide_size

tests/data/groundtruth/docling_v2/powerpoint_unrecognized_shape.pptx.itxt

@@ -0,0 +1,18 @@
+item-0 at level 0: unspecified: group _root_
+  item-1 at level 1: chapter: group slide-0
+    item-2 at level 2: title: Q3 Revenue Summary
+    item-3 at level 2: list: group list
+      item-4 at level 3: list_item: Total revenue grew 18% year-over-year.
+      item-5 at level 3: list_item: Enterprise segment led growth at 24%.
+      item-6 at level 3: list_item: APAC region exceeded targets by 12%.
+  item-7 at level 1: chapter: group slide-1
+    item-8 at level 2: paragraph: Key Metrics
+    item-9 at level 2: paragraph: Monthly active users: 4.2M
+    item-10 at level 2: paragraph: Net retention rate: 112%
+    item-11 at level 2: paragraph: Text in an unrecognized shape
+  item-12 at level 1: chapter: group slide-2
+    item-13 at level 2: title: Next Steps
+    item-14 at level 2: list: group list
+      item-15 at level 3: list_item: 1. Finalize pricing model
+      item-16 at level 3: list_item: 2. Launch APAC campaign
+      item-17 at level 3: list_item: 3. Hire 3 additional SEs