This function is actively used by OsmoPCU but have not been covered by
tests so far. The test code is based on
Minh-Quang Nguyen <minh-quang.nguyen@nutaq.com> submission with some
modifications.
The test's FIXME will be addressed in follow-up patches.
Change-Id: I2ee544256b8675bc62a42493aab66a8eeee54f90
Related: OS#1526
Max