Better diagnosis for null parent.
Observed in 1.509.3:
java.lang.NullPointerException
	at hudson.model.AbstractItem.getRootDir(AbstractItem.java:162)
	at hudson.model.Items.getConfigFile(Items.java:236)
	at hudson.model.AbstractItem.getConfigFile(AbstractItem.java:461)
	at hudson.model.AbstractItem.save(AbstractItem.java:456)
	at hudson.model.Job.save(Job.java:152)
	at hudson.model.AbstractProject.save(AbstractProject.java:268)
	at hudson.diagnosis.OldDataMonitor.doDiscard(OldDataMonitor.java:275)
Merge branch 'master' of github.com:jenkinsci/jenkins
Missing @since.
Fork the compiler jvm.
Merge branch 'master' of github.com:jenkinsci/jenkins
Deprecating hudson field; use jenkins instead.
It is Thread.getThreadGroup that can return null, not ThreadGroup.getName.
https://jenkins.ci.cloudbees.com/job/core/job/jenkins_main_trunk/1436/testReport/hudson.model/UpdateCenter2Test/install/
java.lang.NullPointerException: null
	at hudson.Functions$ThreadSorterBase.<init>(Functions.java:1151)
	at hudson.Functions$ThreadSorterBase.<init>(Functions.java:1142)
	at hudson.Functions$ThreadGroupMap.<init>(Functions.java:1163)
	at hudson.Functions.sortThreadsAndGetGroupMap(Functions.java:1136)
	at org.jvnet.hudson.test.JenkinsRule$2.evaluate(JenkinsRule.java:482)
Synchronizing XPath-related assertions with implementations in HudsonTestCase, using HtmlUnit’s XPath engine rather than Hamcrest’s which does not seem to work in this context at least.
Deprecating SFTPClient.
Updated Japanese localization
[JENKINS-20280] Make it easy to change the implementation. Especially Map.Entry is not so convenient to handle.
[JENKINS-20280] Use topological sorting to decide the order to override variables.
NPE reported in 1.509.3 from OldDataMonitor as part of a general startup failure.
In this case display the reported exceptions differently and be done with it.
java.lang.NullPointerException
	at hudson.diagnosis.OldDataMonitor.report(OldDataMonitor.java:178)
	at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:312)
	at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:222)
	at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
Merge pull request #993 from ikedam/feature/JENKINS-20280_TopologicalSort

[JENKINS-20280] Decide variable overriding order with topological sorting
fixed layout of logger list.
Better icon for labels

Uses http://rrze-icon-set.berlios.de/tango/gallery.html#attribute
Merge pull request #995 from daniel-beck/label-icon

Distinctive icon for labels