Dereference of an explicit null value

Defect 114181 (STATIC_C)
Checker FORWARD_NULL (subcategory deref_constant_null)
File: /test/checkpoint/workers.c
Function real_worker
/test/checkpoint/workers.c, line: 245
Dereferencing null pointer "session".

            if ((ret = session->open_cursor(session, g.cookies[j].uri, NULL, NULL, &cursors[j])) != 0) {

File: /test/checkpoint/workers.c
Function real_worker
/test/checkpoint/workers.c, line: 314
Dereferencing null pointer "session".

        if ((t_ret = session->close(session, NULL)) != 0 && ret == 0) {