FULL PRODUCT VERSION :
java version "1.6.0"
Java(TM) SE Runtime Environment (build 1.6.0-b105)

ADDITIONAL OS VERSION INFORMATION :
2.6.9-42.ELsmp #1 SMP Wed Jul 12 23:27:17 EDT 2006 i686 i686 i386 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
Using java.net.HttpURLConnection to access an NTLM protected site.
Don't want to use new NTLMAuthentication feature (using my own code).
Did not specify an Authenticator, following http://java.sun.com/javase/6/docs/technotes/guides/net/http-auth.html suggestions...


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Open an HttpUrlConnection on a NTLM protected site without specifying a java.net.Authenticator.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
a "401" response code
ACTUAL -
NullPointerException

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.NullPointerException
at sun.net.www.protocol.http.NTLMAuthentication.init(NTLMAuthentication.java:138)
at sun.net.www.protocol.http.NTLMAuthentication.<init>(NTLMAuthentication.java:133)
at sun.net.www.protocol.http.HttpURLConnection.getServerAuthentication(HttpURLConnection.java:1700)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1091)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:373)

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
Possible patch:
in sun.net.www.protocol.http.HttpURLConnection.getServerAuthentication() substitute (line 1700 on current source?)
ret = new NTLMAuthentication(false, url1, a);
with
if (a != null) {
  ret = new NTLMAuthentication(false, url1, a);
}