Control File: a sub-package name cannot be empty or just "*"

When parsing the contents of the Sub-Package field, this error is generated if any one entry is empty or just an asterisk. The asterisk is used to indicate the default package, the one that will not use the sub-package name in its final filename.

VALIDSub-Package: run-time*, development, documentation
INVALIDSub-Package: *, , devel, , admin, core*