[FELIX-4517] Fix possible exception

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1603131 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/bundleplugin/src/main/java/org/apache/felix/bundleplugin/BlueprintPlugin.java b/bundleplugin/src/main/java/org/apache/felix/bundleplugin/BlueprintPlugin.java
index 23f3103..97b3d69 100644
--- a/bundleplugin/src/main/java/org/apache/felix/bundleplugin/BlueprintPlugin.java
+++ b/bundleplugin/src/main/java/org/apache/felix/bundleplugin/BlueprintPlugin.java
@@ -300,9 +300,13 @@
             else
             {
                 Set<String> merge = Create.set();
-                for (Clause clause : parseHeader(analyzer.getProperty(header)))
+                String org = analyzer.getProperty(header);
+                if (org != null && !org.isEmpty())
                 {
-                    merge.add(clause.toString());
+                    for (Clause clause : parseHeader(org))
+                    {
+                        merge.add(clause.toString());
+                    }
                 }
                 for (Clause clause : hdrs.get(header))
                 {