There are the following problems with deploying/undeploying via DeployManagerUtil on Jetty.
1. When running on Jetty the DeployManager (DeployManagerUtil) deploys successfully but copies the context xml file for the deployable to the context directory under the name jetty-context-configure.xml instead of the name of the context. This causes the undeploy not to find the context file.
2. The DeployUtil.undeploy method returns immediately, without undeploying, unless the app server is Tomcat or JBoss. It should also accept Jetty.
3. The DeployUtil.undeploy method ignores the appServerType parameter for some checks and instead uses ServerDetector.isTomcat/isJetty/etc. This is theoretically incorrect because the caller will expect the appServerType parameter to be honored even if it is not the app server currently running, and it is practically incorrect because it will fail when called from Ant.