Description of problem:

A timing issue can allow for the following sporadic NPE that fails a deployment upon start up:

java.lang.NullPointerException
        at org.jboss.as.web.deployment.WebDeploymentService$1.run(WebDeploymentService.java:99)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [rt.jar:1.8.0_40]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [rt.jar:1.8.0_40]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [rt.jar:1.8.0_40]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [rt.jar:1.8.0_40]
        at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_40]
        at org.jboss.threads.JBossThread.run(JBossThread.java:122)
Caused by: java.lang.NullPointerException
        at java.io.File.<init>(File.java:277) [rt.jar:1.8.0_40]
        at org.apache.catalina.core.StandardContext.engineBase(StandardContext.java:4130)
        at org.apache.catalina.core.StandardContext.workBase(StandardContext.java:4137)
        at org.apache.catalina.core.StandardContext.getWorkPath(StandardContext.java:1696)
        at org.apache.catalina.core.StandardContext.postWorkDirectory(StandardContext.java:4401)
        at org.apache.catalina.core.StandardContext.start(StandardContext.java:3667)
        at org.jboss.as.web.deployment.WebDeploymentService.doStart(WebDeploymentService.java:163)
        at org.jboss.as.web.deployment.WebDeploymentService.access$000(WebDeploymentService.java:61)
        at org.jboss.as.web.deployment.WebDeploymentService$1.run(WebDeploymentService.java:96)
        ... 6 more

Version-Release number of selected component (if applicable):


How reproducible:

Easily reproducible with the attached byteman rule

Steps to Reproduce:
1. Configure JBoss using the attached byteman rule:

-javaagent:/path/to/lib/byteman.jar=script:/path/to/01536606.btm,sys:/path/to/lib/byteman.jar

2. Start JBoss with 2 deployments
3. Check for the NPE

Actual results:

Possible NPE


Expected results:

No NPEs