o Minor bugfixes:
    - Prevent using negative indices during unit test runs when read_all()
      fails. Spotted by coverity. Bugfix on 0.2.3.1-alpha.
    - Fix a rare memory leak when checking the nodelist without it being
      present. Found by coverity. Bugfix on 0.2.3.1-alpha.
  o Code simplifications and refactoring:
    - Remove a dead variable in the heartbeat log code. Spotted by coverity.