modify L2MuonSeedGeneratorFromL1T to deal with possible L1 zero charge (backport)

[sarafiorendi]

Backport of #14135 to 80X

[cmsbuild]

A new Pull Request was created by @sarafiorendi for CMSSW_8_0_X.

It involves the following packages:

RecoMuon/L2MuonSeedGenerator

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@battibass, @abbiendi, @jhgoh, @bellan, @trocino, @bachtis, @rociovilar this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/12477/console

[cmsbuild]

+1
Tested at: d8d6ffb
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14136/12477/summary.html

[Martin-Grunewald]

@davidlange6
OK, put in if possible (81X PR is #14135)

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14136/12477/summary.html

[cvuosalo]

@cmsbuild please test
Comparisons did not complete

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/12568/console

[cmsbuild]

+1
Tested at: d8d6ffb
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14136/12568/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14136/12568/summary.html

[cvuosalo]

+1

For #14136 d8d6ffb

Corrected handling of invalid or zero L1 objects in L2MuonSeedGeneratorFromL1T.

#14135 is the 81X version of this PR, and it has already been approved.

The code changes are satisfactory. Jenkins tests against baseline CMSSW_8_0_X_2016-04-20-1100 show no significant differences, except for workflows 1330.0_ZMM_13 and 25202.0_TTbar_13, where the DQM plots show numerous small HLT-related changes expected for this PR. An additional test of RelValZMM_13 with #14147 included against baseline CMSSW_8_0_X_2016-04-18-2300 was performed using this file:
/store/relval/CMSSW_7_1_20_patch2/RelValZMM_13/GEN-SIM/MCRUN2_71_V1_GsRealBS-v1/00000/72F3AF71-C981-E511-87E5-0025905A6088.root
As seen in #14135, the results show improved HLT muon efficiency, but the effects are even greater because in 80X L1 muon objects have the L1 charge problem in the overlap and endcap regions, while in 81X this problem only occurs in the overlap region. Many HLT-related muon DQM plots are now filled where they were empty in the baseline. Here's an example:

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_0_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar

[davidlange6]

+1