Fix missing LHERunInfo header bug

[colizz]

PR description:

Fix a bug that causes the header and comment not properly copied to LHERunInfoPruduct from the produced LHE events. Therefore these entities are missing in LHERunInfoPruduct in the output ROOT file.

PR validation:

Test on the process B2G-RunIISummer19UL17wmLHEGEN-00001 and see LHERunInfoPruduct::headers_size() gives 8 after the fix (otherwise gives 0) in the output ROOT file.

(Resolves: #33690)

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33831/22850

• This PR adds an extra 16KB to repository

• There are other open Pull requests which might conflict with changes you have proposed:

  • File GeneratorInterface/LHEInterface/plugins/ExternalLHEProducer.cc modified in PR(s): Refactoring gen weight storage in EDM + Nano integration #32167, Add argument postGenerationCommand to ExternalLHEProducer and provide mergeLHE.py script #33615

[cmsbuild]

A new Pull Request was created by @colizz (Congqiao Li) for master.

It involves the following packages:

GeneratorInterface/LHEInterface

@SiewYan, @mkirsano, @cmsbuild, @GurpreetSinghChahal, @agrohsje, @alberto-sanchez can you please review it and eventually sign? Thanks.
@alberto-sanchez, @mkirsano this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[colizz]

(here is a quick test out of the box)

cmsrel CMSSW_12_0_X_2021-05-24-2300
cd CMSSW_12_0_X_2021-05-24-2300/src
cmsenv
git cms-merge-topic colizz:dev-120X-fixMissingLHERunInfoHeader

# add a patch to print out info
curl https://gist.githubusercontent.com/colizz/3560bda4a225735d4219bd500a3067c9/raw/3bb1a9ee08f88e4d2922e496bf1bf350df872e7b/a.diff | patch -p1

curl -s -k https://cms-pdmv.cern.ch/mcm/public/restapi/requests/get_fragment/B2G-RunIISummer19UL17wmLHEGEN-00001 --retry 3 --create-dirs -o Configuration/GenProduction/python/B2G-RunIISummer19UL17wmLHEGEN-00001-fragment.py
scram b -j8
cd ../..
cmsDriver.py Configuration/GenProduction/python/B2G-RunIISummer19UL17wmLHEGEN-00001-fragment.py --python_filename B2G-RunIISummer19UL17wmLHEGEN-00001_1_cfg.py --eventcontent RAWSIM,LHE --customise Configuration/DataProcessing/Utils.addMonitoring --datatier GEN,LHE --fileout file:B2G-RunIISummer19UL17wmLHEGEN-00001.root --conditions 112X_mcRun2_asymptotic_v2 --beamspot Realistic25ns13TeVEarly2017Collision --customise_commands process.source.numberEventsInLuminosityBlock="cms.untracked.uint32(100)" --step LHE,GEN --geometry DB:Extended --era Run2_2017 --no_exec --mc -n 20
cmsRun B2G-RunIISummer19UL17wmLHEGEN-00001_1_cfg.py

then please search ">>headers_size" in the printout info.

[colizz]

Resolves: #33690

[agrohsje]

please test

[agrohsje]

Thanks for the fix. All working well. Just tested from my side in CMSSW_11_3_0_pre6. Will approve once tests are done!

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-d6f7ac/15296/summary.html
COMMIT: b18c529
CMSSW: CMSSW_12_0_X_2021-05-24-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/33831/15296/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 8 differences found in the comparisons
• DQMHistoTests: Total files compared: 37
• DQMHistoTests: Total histograms compared: 2650486
• DQMHistoTests: Total failures: 12
• DQMHistoTests: Total nulls: 1
• DQMHistoTests: Total successes: 2650451
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -0.004 KiB( 36 files compared)
• DQMHistoSizes: changed ( 312.0 ): -0.004 KiB MessageLogger/Warnings
• Checked 155 log files, 37 edm output root files, 37 DQM output files
• TriggerResults: no differences found

[agrohsje]

+generators

[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. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1