in src/main/java/org/apache/maven/plugins/gpg/SignAndDeployFileMojo.java [259:272]
private void initProperties() throws MojoExecutionException {
// Process the supplied POM (if there is one)
if (pomFile != null) {
generatePom = false;
Model model = readModel(pomFile);
processModel(model);
}
if (packaging == null && file != null) {
packaging = FileUtils.getExtension(file.getName());
}
}