MNG-5582 MavenSession.getAllProjects() should return all projects in the reactor even if the set is constrained by --projects. The current implementation, however, returns the same constrained list that is returned by MavenSession.getProjects().
This bug seems to have been introduced when
MNG-5775 was implemented.
I came across this bug when I tried to fix an issue in the flatten-maven-plugin. In order to solve the issue a list of all projects in the reactor is needed.