Validation/RecoMuon HTrack: make a copy instead of a reference to a temporary

[slava77]

in M const& errors = fts.cartesianError().matrix(); the cartesianError() returns a temporary by value, while .matrix() returns a reference to it.
For a general return function the underlying temporary would/could be deleted after the expression is executed and the behavior of the result is undefined.
It seems like due to .matrix() being inlined we are getting an extension to the lifetime of the temporary.

This update is to explicitly avoid the undefined behavior.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-34183/23394

• This PR adds an extra 16KB to repository

[cmsbuild]

A new Pull Request was created by @slava77 (Slava Krutelyov) for master.

It involves the following packages:

Validation/RecoMuon

@andrius-k, @kmaeshima, @ErnestaP, @ahmad3213, @cmsbuild, @jfernan2, @rvenditti can you please review it and eventually sign? Thanks.
@HuguesBrun, @abbiendi, @jhgoh, @calderona, @sscruz, @Fedespring, @trocino, @cericeci, @rociovilar 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

[jfernan2]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7cb5a9/16106/summary.html
COMMIT: d3abaa9
CMSSW: CMSSW_12_0_X_2021-06-18-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/34183/16106/install.sh to create a dev area with all the needed externals and cmssw changes.

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• Introduce Quality for PixelTracks. Improve Patatrack duplicate & ambiguity resolution #33889 @VinInn: Introduce Quality for PixelTracks. Improve Patatrack duplicate & ambiguity resolution
• skipPS option for CorrectedECALPFClusterProducer #34134 @hatakeyamak: skipPS option for CorrectedECALPFClusterProducer
• Run3-hcx296 Update some of the cfg's in view of testing SD's to be used #34172 @bsunanda: Run3-hcx296 Update some of the cfg's in view of testing SD's to be used
• Run3-alca187 Update calibration macros in view of discrepancy in the procedure #34116 @bsunanda: Run3-alca187 Update calibration macros in view of discrepancy in the procedure
• Update GEMRECO geometry in online GTs #34165 @francescobrivio: Update GEMRECO geometry in online GTs
• [ALCA_RECONSTRUCTION] Apply code-checks/format #34128 @smuzaffar: [ALCA_RECONSTRUCTION] Apply code-checks/format
• [ALCA] Apply code-checks/format #34127 @smuzaffar: [ALCA] Apply code-checks/format

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7cb5a9/16106/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7cb5a9/16106/git-merge-result

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 8 differences found in the comparisons
• DQMHistoTests: Total files compared: 38
• DQMHistoTests: Total histograms compared: 2785631
• DQMHistoTests: Total failures: 12
• DQMHistoTests: Total nulls: 1
• DQMHistoTests: Total successes: 2785596
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -0.004 KiB( 37 files compared)
• DQMHistoSizes: changed ( 312.0 ): -0.004 KiB MessageLogger/Warnings
• Checked 160 log files, 37 edm output root files, 38 DQM output files
• TriggerResults: no differences found

[jfernan2]

+1

[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