In the 1.x driver, where MongoCursor is an Iterator, each call to next() when iterating through the cursor will invoke php_mongo_handle_error(). Phongo's move_forward iterator handle currently does not check for errors if mongoc_cursor_next() returns false. Errors are only caught when the query or command is first executed.

One possible way to test for this might be killing a cursor between getmore calls. The current code would simply not return more results, while we would actually expect an exception for issuing a getmore on an invalid cursor ID.