Expand the lint warning added under JDK-8071961 to cover
protected classes as well as
public classes having default constructors exposed accidentally, a
protected class can have its default constructors exposed too as part of the full API of a package.
Expand the lint warning to cover
protected classes with the other conditions staying the same. In detail, a warning is issued for
protected classes in a named package that has an unqualified export from its module where, for nested classes, all the syntactically enclosing classes must are either
javac.opt.Xlint.desc.missing-explicit-ctor=\ - Warn about missing explicit constructors in public classes in exported packages. + Warn about missing explicit constructors in public and protected classes in exported packages.