bugfix: - fix invalid assert statement. - fix deprecated usage of NULL.
bugfix:
- fix invalid assert statement.
- fix deprecated usage of NULL.

Signed-off-by: Kim Kulling <ab1850e765cb36d3d392c95b68ac3e34036b2afe@googlemail.com>

kimkulling/cppcore,kimkulling/cppcore,kimkulling/cppcore,kimkulling/cppcore