PYTHON-4084 Fix BSON inflation for DBRef (#1458)

bson/_cbsonmodule.c

@@ -1884,6 +1884,11 @@ static PyObject* get_value(PyObject* self, PyObject* name, const char* buffer,
                 goto invalid;
             }
 
+            if (options->is_raw_bson) {
+                *position += size;
+                break;
+            }
+
             /* Hook for DBRefs */
             value = _dbref_hook(self, value);
             if (!value) {

test/test_raw_bson.py

@@ -22,7 +22,7 @@ sys.path[0:0] = [""]
 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 @@ class TestRawBSONDocument(IntegrationTest):
         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()