LOGGING-145 - LogFactoryImpl.setAttribute - possible NPE

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/logging/trunk@1362996 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/logging/impl/LogFactoryImpl.java

@@ -406,7 +406,7 @@ public class LogFactoryImpl extends LogFactory {
         }
         
         if (name.equals(TCCL_KEY)) {
-            useTCCL = Boolean.valueOf(value.toString()).booleanValue();
+            useTCCL = value != null && Boolean.valueOf(value.toString()).booleanValue();
         }
 
     }