Title: #70: check_duplicate: check name member before using it
The second patch resolves https://fedorahosted.org/sssd/ticket/3231
and adds a
test for the issue.
The first patches fixes a potential memory leak which so far was only relevant
in the tests.
To pull the PR as Git branch:
git remote add ghsssd https://github.com/SSSD/sssd
git fetch ghsssd pull/70/head:pr70
git checkout pr70