in src/main/java/org/apache/maven/plugins/war/overlay/OverlayManager.java [200:207]
private boolean compareOverlayWithArtifact(Overlay overlay, Artifact artifact) {
return (Objects.equals(overlay.getGroupId(), artifact.getGroupId())
&& Objects.equals(overlay.getArtifactId(), artifact.getArtifactId())
&& Objects.equals(overlay.getType(), artifact.getType())
// MWAR-241 Make sure to treat null and "" as equal when comparing the classifier
&& Objects.equals(
Objects.toString(overlay.getClassifier()), Objects.toString(artifact.getClassifier())));
}