The NPE can occur if a build fails during checkout and hence the run phase
never gets called. See JENKINS-10831 for an example of this happening.

- Added a RenameListener to Fingerprint. When the listener is invoked for
  renamed projects, it will iterate over all the builds of the project looking
  for fingerprint actions. If the build was the originator of the fingerprint,
  the buildPtr is updated; (had to make the name non-final to allow for this).
  If the build is the consumer of a fingerprint, the usages are updated.

   core/src/main/java/hudson/model/Fingerprint.java

- Expose the fingerprint data inline with the build data in the remote API.
  The renaming code also uses this method as a convenient way to get the
  fingerprints for a build.

   core/src/main/java/hudson/model/AbstractBuild.java

- Test.

   test/src/test/java/hudson/tasks/FingerprinterTest.java

happen.

This happens because the version number isn't computed yet, but we try
to put that into HTTP header.

Fixing this by making <st:header/> tolerate null in value or name.

JVM.

that this feature is now deprecated.

Non-functional change.

Ryan reported a dead lock caused by getView(String), so removing synchronized and requiring the list be concurrently iterable.

mavenExecutionResult exceptions not empty
message : Internal error: java.lang.NullPointerException
cause : null
Stack trace :
org.apache.maven.InternalErrorException: Internal error: java.lang.NullPointerException
	at org.apache.maven.lifecycle.internal.BuilderCommon.handleBuildError(BuilderCommon.java:128)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:95)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:319)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
	at org.jvnet.hudson.maven3.launcher.Maven3Launcher.main(Maven3Launcher.java:79)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239)
	at org.jvnet.hudson.maven3.agent.Maven3Main.launch(Maven3Main.java:158)
	at hudson.maven.Maven3Builder.call(Maven3Builder.java:121)
	at hudson.maven.Maven3Builder.call(Maven3Builder.java:73)
	at hudson.remoting.UserRequest.perform(UserRequest.java:118)
	at hudson.remoting.UserRequest.perform(UserRequest.java:48)
	at hudson.remoting.Request$2.run(Request.java:287)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.NullPointerException
	at hudson.maven.MojoInfo.intercept(MojoInfo.java:208)
	at hudson.maven.reporters.MavenArtifactArchiver.preExecute(MavenArtifactArchiver.java:74)
	at hudson.maven.Maven3Builder$MavenExecutionListener.recordMojoStarted(Maven3Builder.java:535)
	at hudson.maven.Maven3Builder$MavenExecutionListener.forkStarted(Maven3Builder.java:671)
	at org.apache.maven.lifecycle.internal.DefaultExecutionEventCatapult.fire(DefaultExecutionEventCatapult.java:94)
	at org.apache.maven.lifecycle.internal.DefaultExecutionEventCatapult.fire(DefaultExecutionEventCatapult.java:42)
	at org.apache.maven.lifecycle.internal.MojoExecutor.executeForkedExecutions(MojoExecutor.java:328)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:199)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
	... 24 more
channel stopped
FATAL: null
java.lang.NullPointerException
	at hudson.maven.MavenModuleSetBuild$RunnerImpl.doRun(MavenModuleSetBuild.java:833)
	at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:448)
	at hudson.model.Run.run(Run.java:1376)
	at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:479)
	at hudson.model.ResourceController.execute(ResourceController.java:88)
	at hudson.model.Executor.run(Executor.java:230)