add states to GsfMultiStateUpdator MultiState only if the localError matrix is valid

[mmusich]

resolves #39026

PR description:

Title says it all, in order to avoid multi-states during electron tracking that lead to exceptions in BasicMultiTrajectoryState when mixing states with valid and invalid local errors.

PR validation:

Run successfully the configuration posted at #39026 (comment).

If this PR is a backport please specify the original PR and why you need to backport that PR. If this PR will be backported please specify to which release cycle the backport is meant for:

Not a backport, but if accepted, it needs to be backported to 12_4_X for data-taking

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-39056/31558

• This PR adds an extra 12KB to repository

[cmsbuild]

A new Pull Request was created by @mmusich (Marco Musich) for master.

It involves the following packages:

• TrackingTools/GsfTracking (reconstruction)

@jpata, @cmsbuild, @mandrenguyen, @clacaputo can you please review it and eventually sign? Thanks.
@VourMa, @felicepantaleo, @GiacomoSguazzoni, @JanFSchulte, @rovere, @VinInn, @bellan, @ebrondol, @lecriste, @gpetruc, @mmusich, @mtosi, @dgulhan this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy, @rappoccio you are the release manager for this.

cms-bot commands are listed here

[mmusich]

@cmsbuild, please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9077aa/26810/summary.html
COMMIT: 2b81038
CMSSW: CMSSW_12_5_X_2022-08-14-2300/el8_amd64_gcc10
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/39056/26810/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: 2 differences found in the comparisons
• DQMHistoTests: Total files compared: 51
• DQMHistoTests: Total histograms compared: 3692476
• DQMHistoTests: Total failures: 8
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3692446
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 50 files compared)
• Checked 212 log files, 49 edm output root files, 51 DQM output files
• TriggerResults: no differences found

[jpata]

Thanks @mmusich!

@wrtabb @SohamBhattacharya @cms-sw/egamma-pog-l2 do you think this could change physics in rare cases, or does it only fix a job that would otherwise crash?

[mmusich]

type tracking, egamma, bug-fix

[swagata87]

do you think this could change physics in rare cases, or does it only fix a job that would otherwise crash?

Running the RECO step on 1k Z'->EE MC events, with and w/o this fix, I do not see any difference in electron pT distribution. So, to me it seems that overall there will be no change in physics, but we will get rid of the rare crashes that are happening now in Gsf tracking step.

[swagata87]

Also tagging incoming EGM-RECO convenor Prasant Kumar Rout @Prasant1993

[jpata]

+reconstruction

• bugfix for Crash in GsfTrackProducer/'lowPtGsfEleGsfTracks' on ParkingDoubleMuonLowMass5 Prompt Reco dataset  #39026
• no reco changes expected

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

[perrotta]

+1