Handle null log4j logger param to constructor better than just causing NullPointerException.

Thanks to Lilianne E. Blaze for the patch; see jira LOGGING-111.


git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/logging/trunk@476774 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/logging/impl/Log4JLogger.java

@@ -109,9 +109,14 @@ public class Log4JLogger implements Log, Serializable {
         this.logger = getLogger();
     }
 
-    /** For use with a log4j factory.
+    /** 
+     * For use with a log4j factory.
      */
     public Log4JLogger(Logger logger ) {
+        if (logger == null) {
+            throw new IllegalArgumentException(
+                "Warning - null logger in constructor; possible log4j misconfiguration.");
+        }
         this.name = logger.getName();
         this.logger=logger;
     }