[FIXED JENKINS-38473] Set a short timeout on the socket when using it to wake the acceptor thread. (#2564)

* [FIXED JENKINS-38473] Set a short timeout on the socket when using it to wake the acceptor thread.

* [JENKINS-38473] Remove leftover typing in wrong window

[FIXED JENKINS-38534] Isolate the code that requires the `Jenkins` class to be loaded from an agent code path

* [FIX JENKINS-18114] Exclude /cli URL from crumb requirement

* [JENKINS-18114] Fix test: Don't send the crumb

The CLI doesn't do this either.

- Add tooltip to notification button
- Move CSS/JS into an adjunct
- Check adcitve admin monitors status last
- Don't show on /configure URL

Fix setting up slave agent port through -Djenkins.model.Jenkins.slaveAgentPort on startup.
Add -Djenkins.model.Jenkins.slaveAgentPortEnforce=true to enforce slave agent port on every start,  and an administrative monitor in case the value is modified through UI.

* [JENKINS-35184] Servlet API dependent bits in a inner-class

This is in order to avoid loading ServletContextListener class
from slaves classloader.

* [JENKINS-35184] Don't use SystemProperties while initializing remote agents

This rolls back the previous commit and introduces a new way to construct
RingBufferLogHandler which avoids relying on SystemProperties to get the
default size.

* [JENKINS-35184] Mark SystemProperties as OnMaster only class

Adding `OnMaster` annotation does not prevent the class from being
loaded on remote agent but it gives a hint that this class should not
be used on a remote agent.

* [JENKINS-35184] Set SLAVE_LOG_HANDLER at the very beginning

In the previous code cleaning existing log handlers, SLAVE_LOG_HANDLER
is always null, as static fields are scoped by classloader.

There were two issues preventing the build history from updating properly:
1) The next build number being fetched wasn't taking into account running builds, so any builds already running when the page is refreshed would be ignored. The fix was to use nextBuildNumberToFetch if it is available (which is the case if there are running builds) and to fall back to the next build otherwise.
2) The first transient build key (used to clear out builds from the history that are being updated) wasn't being set when the page first loads. This was fixed by making getHistoryPageFilter calculate the value so that it happens in all cases rather than just during the ajax call.

Add display name for all admin monitors in core.

* [JENKINS-37857] Prompt user whether to add the job to the current view

* [JENKINS-37857] Fix review items from @daniel-beck

* [FIXED JENKINS-37731] Change symbol and constructor for SCMTrigger.

Using "scm" as the @Symbol led to collisions with the "scm" global
variable in Pipeline, so that had to go. Changed it to "pollScm". Also
moved the @DataBoundConstructor to the single-parameter constructor,
deprecated the two-parameter constructor, created a @DataBoundSetter
for ignorePostCommitHooks, and added a getter for "scmpoll_spec" to
fix snippet generator and general syntactic goodness.

So now, with this, it's possible to do:

properties([
  pipelineTriggers([
    pollScm('@daily')
  ])
])

Tada.

Tests for the snippet generator and job property stuff will be landing
in a separate PR for workflow-multibranch.

* Review comments.

* Updating @since to 2.22

For example when Descriptor was defined as field and without @Extension .
Signed-off-by: NKanstantsin Shautsou <kanstantsin.sha@gmail.com>

* [JENKINS-37874] - Log SEVERE messages if Jenkins does not reach COMPLETED stage during startup or reload

* [JENKINS-37874] - Add Administrative monitor for the COMPLETED state

* [JENKINS-37874] - Polish log messages

* remove restriction to be able to ovverride the method in subclasses

* since needs to be adjusted

Add newline after the text in userContent/readme.txt

* [JENKINS-36748] Add a test case and not process null specs

* [JENKINS-36748] Correct license and add a minor comment

* [JENKINS-36748] Add a Waning logger when spec is null

[FIXED JENKINS-36537] Allow the use of custom json signature validator for metadata signature check (#2442)

* JENKINS-33374 - correct restart behavior during setup wizard

* Add tests

* One more test

* Test Windows junctions before Java 7 symlink

Apparently Java 7 (and later) do not count Windows junctions as
symlinks.  When you drill down into the BasicFileAttributes structure,
reparse points are only counted under isOther.  So, since we already
have code that properly detects Windows Junctions, let's use that first
and then fallback to the Java 7 code.

* Add comment for change & link bug.

* Add test case

* Switch to Functions.isWindows().

* Use non-deprecated APIs for tmp file/dir mgmt

* Add better debugging.

* Allow spaces in junction name & dir name.

To do that, it was easier to use ProcessBuilder vs building up the correct
string in code to send to cmd.exe.

Also, I'll note that according to http://ss64.com/nt/syntax-internal.html,
mklink is in internal cmd.exe command.  So, it must be invoked through
"cmd.exe /c" for it to work.

* Remove comment mentioning bug number.

* Remove debugging output, per Baptiste's request

* Add newline at end of file.

* Make sure that the junction was removed.

* Use assertEquals to show retcode of Process.waitFor.

* Fix compilation errors by importing functions

[FIXED JENKINS-37561, CID-1205051] - Prevent resource leak in AntClassLoader#findClassInComponents() (#2517)

It has been originally reported by Coverity in https://scan5.coverity.com/reports.htm#v36021/p10292/fileInstanceId=97573616&defectInstanceId=28155759&mergedDefectId=1205051. It happens on Exceptional paths only, but actually I see 31 runaway handlers on my jenkins-2.18 instance (maybe happens due to plugin dynamic load failure)

The issue happens, because finally block is misplaced. It handles only the last stream in this cycle

* [JENKINS-37332] - Improve diagnostics of non-closed streams during reading of the manifests in PluginManager

* [JENKINS-37332] - Leakless processing of JarUrlConnection during Manifest parsing

* [JENKINS-37332] - Also implement leak-safe method for retrieving file modification date

* [JENKINS-37332] - Add spotcheck methods for manifest file access + Javadoc

* [JENKINS-37332] - Also test multi-line and empty attributes in the test

Provide a sensible default implementation of configure.

- A pure unit tests will suffice