We have a legacy application using a library with properties configuration files where some properties are only keys; Example:
property.key=value or property.key=
Until version 1.7 those properties where present with no value in our CompositeConfiguration instance.
Starting with version 1.8 (introducing a private not overridable regex pattern) those properties are now left out of our application configuration.
Since we don't own the lib we can't move to latest version of commons-configuration and are stuck with version 1.7