Bug 31510

This problem causes severe memory leaks in JBoss app server with Jetty servlet 
container installed (that is using Jasper). I tested it with JBoss 3.2.6RC1 and 
Jetty 5.0.0. Please see related bug reports: https://sourceforge.net/tracker/?
func=detail&aid=973162&group_id=22866&atid=376685 and 
https://sourceforge.net/tracker/?
func=detail&aid=1038066&group_id=7322&atid=107322. In short, after JBoss web 
application context is destroyed, there is still a hard reference chain (see 
http://kanika.yi.org/~alexei/jbossleaks/refs-from-jasper5-PageContext-pool-to-
UnifiedClassLoader3.html) from Jasper's pool of JspContexts to JBoss' 
UnifiedClassLoader3. The most logical place to break the chain is, in my 
opinion, to set org.apache.jasper.runtime.JspWriterImpl.response field to null 
inside JspWriterImpl.recycle() method. It looks safe, because JspWriterImpl is 
always initialized with a new response object before use. And it looks logical, 
because why should a recycled JspWriter keep reference to a response which it 
will never make use of, being recycled. In my test instalation, adding 

response = null;

to JspWriterImpl.recycle() resolves the problem.