go-offline / resolve-plugins does not resolve all plugin dependencies

The attached pom.xml is a very simple JAR project, without any direct dependencies or plugin dependencies.

Start with an empty local repository, and run mvn dependency:go-offline on it. Some files get downloaded, but not everything that is needed for the build. If you run "mvn -o package" afterwards, you end up with the following error:

[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] The plugin 'org.apache.maven.plugins:maven-resources-plugin' does not exist or no valid version could be found

Afterwards, even "mvn package" without the "-o" parameter does not work any longer.