forceCreation has no effect when skipIfEmpty is true

[elharo]

Bug

When both skipIfEmpty=true and forceCreation=true are set, forceCreation has no effect. The execute() method checks skipIfEmpty first and returns early without calling createArchive(), even though the user explicitly requested forced creation.

Location

AbstractJarMojo.java:303-306:

public void execute() throws MojoException {
    if (skipIfEmpty && isEmpty(getClassesDirectory())) {
        getLog().info(String.format("Skipping packaging of the %s.", getType()));
    } else {
        ...
    }
}

Problem

If a user configures both skipIfEmpty=true and forceCreation=true, the intent is presumably: "skip if empty, unless force is requested." However, skipIfEmpty always takes priority. forceCreation is only evaluated inside createArchive() which is never reached when the content directory is empty.

The @Parameter documentation for forceCreation (lines 114-124) describes it as forcing recreation of the JAR even if inputs have not changed. A user might reasonably expect that forceCreation=true would override skipIfEmpty=true and still produce the JAR.

Suggested fix

The execute() method should only skip when both skipIfEmpty=true and forceCreation=false, i.e.:

if (skipIfEmpty && !forceCreation && isEmpty(getClassesDirectory())) {

[elharo]

It's not obvious to me that forceCreation should override skipIfEmpty. Either way though we should document this behavior. I'm inclined to stick with the existing behavior and document it.