in src/main/java/org/apache/maven/archiver/MavenArchiver.java [225:235]
private void addManifestAttribute(Manifest manifest, String key, String value) throws ManifestException {
if (!(value == null || value.isEmpty())) {
Manifest.Attribute attr = new Manifest.Attribute(key, value);
manifest.addConfiguredAttribute(attr);
} else {
// if the value is empty, create an entry with an empty string
// to prevent null print in the manifest file
Manifest.Attribute attr = new Manifest.Attribute(key, "");
manifest.addConfiguredAttribute(attr);
}
}