BUG: Fix handling of zero-length StreamObject (#3485)

Closes #3052.

---------

Co-authored-by: stefan6419846 <96178532+stefan6419846@users.noreply.github.com>

Author: Likend

pypdf/generic/_data_structures.py

@@ -634,7 +634,7 @@ def read_unsized_from_stream(
             if length is None:  # if the PDF is damaged
                 length = -1
             pstart = stream.tell()
-            if length > 0:
+            if length >= 0:
                 data["__streamdata__"] = stream.read(length)
             else:
                 data["__streamdata__"] = read_until_regex(

tests/test_generic.py

@@ -1265,3 +1265,14 @@ def test_build_link__go_to_action_without_destination():
     for page in reader.pages:
         writer.add_page(page)
     assert len(writer.pages) == len(reader.pages)
+
+
+@pytest.mark.enable_socket
+def test_dictionaryobject__length_0_stream():
+    """Test for issue #3052."""
+    url = "https://github.com/user-attachments/files/18734105/correct.pdf"
+    name = "issue3052.pdf"
+    writer = PdfWriter(clone_from=BytesIO(get_data_from_url(url, name=name)))
+    output = BytesIO()
+    writer.write(output)
+    assert b"\n8 0 obj\n<<\n/Length 0\n>>\nstream\n\nendstream\nendobj\n" in output.getvalue()