Follow-up to tasks #6619: fatal error with advanced criteria

Change-Id: Ib8e22a373d07366c31c7411d9b62f0538bf16336
Merge commit 'refs/changes/75/2275/1' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Follow-up to tasks #6619: fatal error with advanced criteria

Change-Id: Id07f300c98f2ff47e9c6daca00776b413595e208
This is Tuleap 6.12.99.34

Change-Id: I611f8ff6b1c0ad3e240b0de6ab3a686b36965637