Overview
The clearReferencesThreadLocals() method of WebappClassLoader clears two Thread tables from references to the WebappClassLoader. When using axis, the tables can have a HashMap as key, which contains (possibly after many nested HashMaps) a class that was loaded by the WebappClassLoader.

Steps to reproduce
Create a web application that uses the axis 1 SOAP interface. Have the application call ((WebappClassLoader) getClass().getClassLoader()).setClearReferencesThreadLocals(true). Deploy the application in Tomcat. Make a SOAP call to the axis server. Undeploy the web application. Verify in catalina.out that there are warnings about ThreadLocal keys being forcibly unregistered.
Wait an hour, make a memory dump using jmap, and inspect it using jhat.

Actual results
The WebappClassLoader is still present. Its "reference chains from rootset" page shows no references directly from java.lang.ThreadLocal$ThreadLocalMap to an object of a class that is loaded by this WebappClassLoader. It does show references via java.lang.ThreadLocal$ThreadLocalMap and one or more nested HashMaps to the WebappClassLoader:
Static reference from org.apache.catalina.ServerFactory.server (class org.apache.catalina.ServerFactory)
--> org.apache.catalina.core.StandardServer@0xeb400668 (67 bytes) (field services:)
--> [Lorg.apache.catalina.Service;@0xeb4b4178 (12 bytes) (Element 0 of [Lorg.apache.catalina.Service;@0xeb4b4178:)
--> org.apache.catalina.core.StandardService@0xeb4b4188 (62 bytes) (field container:)
--> org.apache.catalina.core.StandardEngine@0xeb4b42c8 (129 bytes) (field thread:)
--> java.lang.Thread@0xeb58b6e0 (104 bytes) (field threadLocals:)
--> java.lang.ThreadLocal$ThreadLocalMap@0xeb58b800 (20 bytes) (field table:)
--> [Ljava.lang.ThreadLocal$ThreadLocalMap$Entry;@0xeb58b818 (72 bytes) (Element 8 of [Ljava.lang.ThreadLocal$ThreadLocalMap$Entry;@0xeb58b818:)
--> java.lang.ThreadLocal$ThreadLocalMap$Entry@0xeb58b908 (28 bytes) (field value:)
--> java.util.HashMap@0xeb58b928 (40 bytes) (field table:)
--> [Ljava.util.HashMap$Entry;@0xeb58b950 (72 bytes) (Element 0 of [Ljava.util.HashMap$Entry;@0xeb58b950:)
--> java.util.HashMap$Entry@0xeb58bb40 (24 bytes) (field key:)
--> class org.apache.axis.types.Notation (84 bytes) (??:)
--> org.apache.catalina.loader.WebappClassLoader@0xeb5a84a0 (157 bytes)


Expected results
The WebappClassLoader for this application is not present anymore.

Build date & platform
Downloaded Core tar.gz from http://tomcat.apache.org/download-70.cgi