Fix UBSAN errors in RecoJets/JetProducers

[Dr15Jones]

PR description:

• Avoid dereference of nullptr in PileupJetIdProducer
• Avoid 0 length VLAs in VirtualJetProducer

PR validation:

The code compiles.

This is a technical change and is not expected to cause any changes to results.

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27569/10967

• This PR adds an extra 24KB to repository

Code check has found code style and quality issues which could be resolved by applying following patch(s)

• code-checks:
  https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27569/10967/code-checks.patch
  e.g. curl https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27569/10967/code-checks.patch | patch -p1
  You can also run scram build code-checks to apply code checks directly

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27569/10968

• This PR adds an extra 24KB to repository

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for master.

It involves the following packages:

RecoJets/JetProducers

@perrotta, @cmsbuild, @slava77 can you please review it and eventually sign? Thanks.
@rappoccio, @jdolen, @ahinzmann, @jdamgov, @yslai, @nhanvtran, @gkasieczka, @clelange, @schoef, @mariadalfonso, @seemasharmafnal this is something you requested to watch as well.
@davidlange6, @slava77, @fabiocos you are the release manager for this.

cms-bot commands are listed here

[Dr15Jones]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/1552/console Started: 2019/07/19 22:27

[cmsbuild]

+1
Tested at: dc47487
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7e9ddc/1552/summary.html

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7e9ddc/1552/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 32
• DQMHistoTests: Total histograms compared: 2622600
• DQMHistoTests: Total failures: 0
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2622298
• DQMHistoTests: Total skipped: 302
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 31 files compared)
• Checked 133 log files, 14 edm output root files, 32 DQM output files

[perrotta]

+1

• Technical: it implements what stated in the description
• Jenkins tests pass and show no differences wrt baseline

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @davidlange6, @slava77, @smuzaffar, @fabiocos (and backports should be raised in the release meeting by the corresponding L2)

[fabiocos]

+1