PYTHON-4084 Fix BSON inflation for DBRef

bson/_cbsonmodule.c

@@ -1880,6 +1880,12 @@ static PyObject* get_value(PyObject* self, PyObject* name, const char* buffer,
 
             value = elements_to_dict(self, buffer + *position,
                                      size, options);
+
+            if (options->is_raw_bson) {
+                *position += size;
+                break;
+            }
+
             if (!value) {
                 goto invalid;
             }

test/test_raw_bson.py

@@ -22,7 +22,7 @@
 from test import client_context, unittest
 from test.test_client import IntegrationTest
 
-from bson import Code, decode, encode
+from bson import Code, DBRef, decode, encode
 from bson.binary import JAVA_LEGACY, Binary, UuidRepresentation
 from bson.codec_options import CodecOptions
 from bson.errors import InvalidBSON
@@ -205,6 +205,14 @@ def test_contains_code_with_scope(self):
         self.assertEqual(decode(encode(doc)), {"value": Code("x=1", {})})
         self.assertEqual(doc["value"].scope, RawBSONDocument(encode({})))
 
+    def test_contains_dbref(self):
+        doc = RawBSONDocument(encode({"value": DBRef("test", "id")}))
+        raw = {"$ref": "test", "$id": "id"}
+        raw_encoded = encode(decode(encode(raw)))
+
+        self.assertEqual(decode(encode(doc)), {"value": DBRef("test", "id")})
+        self.assertEqual(doc["value"].raw, raw_encoded)
+
 
 if __name__ == "__main__":
     unittest.main()