Our JNLP connection shall work directly and not via Proxy.

Because our Linux environment per default sets "http_proxy" environment variable and java detects this per default before the java net.properties (jre/lib/net.properties), we started the JNLP Connection with JAVA_OPTS:

"-Dhttp.proxyHost=... -Dhttp.proxyPort=... -Dhttp.nonProxyHosts=..."

Until slave version 2.49 this worked fine. Beginning with Version 2.50 we got an error:

Apr 24, 2015 3:11:04 PM hudson.remoting.jnlp.Main createEngine
INFO: Setting up slave: xxxx
Apr 24, 2015 3:11:04 PM hudson.remoting.jnlp.Main$CuiListener <init>
INFO: Jenkins agent is running in headless mode.
Apr 24, 2015 3:11:04 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Locating server among http://xxx/ci/
Apr 24, 2015 3:11:05 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Handshaking
Apr 24, 2015 3:11:05 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to xxx:25000
Apr 24, 2015 3:11:15 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to xxx:25000 (retrying:2)
java.io.IOException: Got a bad response from proxy: HTTP/1.0 403 Forbidden
at hudson.remoting.Engine.connect(Engine.java:357)
at hudson.remoting.Engine.run(Engine.java:241)

Seems the http.nonProxyHosts is not considered and boolean "isProxy" is the to true:
(see Line 357, src/main/java/hudson/remoting/Engine.java, https://github.com/jenkinsci/remoting/commit/08b910c7df9a1356b6c53f885c63ea6523e22943)

We could unset the environment http_proxy variable and start the agent without additional JAVA_OPTS, but in this case the needed environment variable is not exported to the agent shell build tasks.

Main-Class: hudson.remoting.Launcher
Version: 2.50