be defensive.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@7470 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/maven/reporters/MavenAbstractArtifactRecord.java

@@ -138,7 +138,7 @@ public abstract class MavenAbstractArtifactRecord<T extends AbstractBuild<?,?>>
     }
 
     public boolean hasBadge() {
-        return !records.isEmpty();
+        return records!=null && !records.isEmpty();
     }
 
     public HistoryWidgetImpl getHistoryWidget() {