FELIX-4186: Fixed NPE in dependency manager Logger.


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1523504 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/Logger.java b/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/Logger.java
index 9bc4edf..2084ed4 100644
--- a/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/Logger.java
+++ b/dependencymanager/core/src/main/java/org/apache/felix/dm/impl/Logger.java
@@ -195,7 +195,7 @@
         }
         // if the current logger is going away, release it and try to
         // find another one
-        else if ((event.getType() == ServiceEvent.UNREGISTERING) && m_logRef.equals(event.getServiceReference())) {
+        else if ((event.getType() == ServiceEvent.UNREGISTERING) && m_logRef != null && m_logRef.equals(event.getServiceReference())) {
             // Unget the service object.
             m_context.ungetService(m_logRef);
             // Try to get an existing log service.