fix(deepdoc): guard docling crop against missing page images (#17147)

deepdoc/parser/docling_parser.py

@@ -174,6 +174,26 @@ class DoclingParser(RAGFlowPdfParser):
         if not poss:
             return (None, None) if need_position else None
 
+        # a position tag is emitted even when page rendering failed (__images__ leaves
+        # page_images empty), and a tag can name a page beyond the rendered range, so
+        # indexing page_images below would raise IndexError. mirror
+        # cropout_docling_table and the sibling parsers: bail out when there are no
+        # page images and drop positions that fall outside them.
+        if not getattr(self, "page_images", None):
+            self.logger.warning("[Docling] crop called without page images; skipping image generation.")
+            return (None, None) if need_position else None
+
+        page_count = len(self.page_images)
+        valid_poss = []
+        for p in poss:
+            if p[0] and all(0 <= pn < page_count for pn in p[0]):
+                valid_poss.append(p)
+            else:
+                self.logger.warning(f"[Docling] Position on pages {p[0]} is out of range for {page_count} rendered page(s); skipping it.")
+        poss = valid_poss
+        if not poss:
+            return (None, None) if need_position else None
+
         GAP = 6
         pos = poss[0]
         poss.insert(0, ([pos[0][0]], pos[1], pos[2], max(0, pos[3] - 120), max(pos[3] - GAP, 0)))

test/unit_test/deepdoc/parser/test_docling_parser_remote.py

@@ -159,3 +159,32 @@ def test_remote_chunked_request_with_ignored_flag_does_not_log_success(monkeypat
     flat = " ".join(record.getMessage() for record in caplog.records)
     assert "Successfully used native chunking" not in flat
     assert "Server ignored chunking request" in flat
+
+
+@pytest.mark.p2
+def test_crop_without_page_images_returns_none(monkeypatch):
+    """Position tags are emitted even when page rendering failed and left
+    ``page_images`` empty, so ``crop`` must bail out instead of raising
+    IndexError while indexing the empty list."""
+    module = _load_docling_parser(monkeypatch)
+    parser = module.DoclingParser(docling_server_url="http://docling.local")
+    parser.page_images = []
+
+    tag = "@@1\t1.0\t2.0\t3.0\t4.0##"
+    assert parser.crop(tag, need_position=True) == (None, None)
+    assert parser.crop(tag) is None
+
+
+@pytest.mark.p2
+def test_crop_drops_positions_beyond_rendered_pages(monkeypatch):
+    """A tag naming a page past the rendered range must be filtered out rather
+    than indexed, mirroring the range check in cropout_docling_table."""
+    module = _load_docling_parser(monkeypatch)
+    parser = module.DoclingParser(docling_server_url="http://docling.local")
+    # a single rendered page; the sentinel is never indexed because the
+    # out-of-range position is dropped first.
+    parser.page_images = [object()]
+
+    tag = "@@5\t1.0\t2.0\t3.0\t4.0##"
+    assert parser.crop(tag, need_position=True) == (None, None)
+    assert parser.crop(tag) is None