ID-19: fix NullPointerException on missing <build>

Author: mlookaxw

CHANGELOG.adoc

@@ -52,6 +52,12 @@ The "info" section is no longer created or updated for "update" certificates.
 
 
 NOTE: To enable the previous behavior, use the `--cert-config-update` parameter of the configuration tool or the `axway.tools.cfg.cert.updateConfigured` property of the plugin.
+
+|https://github.com/Axway-API-Management-Plus/apigw-maven-plugin/issues/19[#19]
+|Fix
+|On flattening the resulting POM a NullPointerException occurred if the `pom.xml` has no <build> element (e.g. in case of the <build> element is defined in the parent POM).
+
+The issue occurred for server and deployment projects.
 |===
 
 == Version 0.6.0

src/main/java/com/axway/maven/apigw/AbstractFlattendProjectArchiveMojo.java

@@ -1,6 +1,11 @@
 package com.axway.maven.apigw;
 
+import java.util.List;
+
+import org.apache.maven.model.Build;
+import org.apache.maven.model.Dependency;
 import org.apache.maven.model.Model;
+import org.apache.maven.model.Plugin;
 
 public abstract class AbstractFlattendProjectArchiveMojo extends AbstractProjectArchiveMojo {
 
@@ -10,10 +15,19 @@ protected Model generateResultPom() {
 		Model reducedModel = model.clone();
 
 		// Remove all dependences
-		reducedModel.getDependencies().clear();
+		List<Dependency> deps = reducedModel.getDependencies();
+		if (deps != null) {
+			deps.clear();
+		}
 
 		// Remove all plugins
-		reducedModel.getBuild().getPlugins().clear();
+		Build build = reducedModel.getBuild();
+		if (build != null) {
+			List<Plugin> plugins = build.getPlugins();
+			if (plugins != null) {
+				plugins.clear();
+			}
+		}
 
 		return reducedModel;
 	}