Don't crash on empty tensor contraction

[smuzaffar]

https://gitlab.com/libeigen/eigen/-/merge_requests/1287

[smuzaffar]

please test

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for branch cms/master/3bb6a48d8c171cf20b5f8e48bfb4e424fbd4f79e.

@iarspider, @smuzaffar, @aandvalenzuela can you please review it and eventually sign? Thanks.
@antoniovilela, @sextonkennedy, @rappoccio you are the release manager for this.
cms-bot commands are listed here

[cmsbuild]

cms-bot internal usage

[cmsbuild]

-1

Failed Tests: UnitTests
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-c01862/37124/summary.html
COMMIT: 8d6ee2b
CMSSW: CMSSW_14_0_X_2024-01-30-2300/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-externals/eigen-git-mirror/8/37124/install.sh to create a dev area with all the needed externals and cmssw changes.

Unit Tests

I found 1 errors in the following unit tests:

---> test testG4Refitter had ERRORS

Comparison Summary

Summary:

• You potentially removed 22 lines from the logs
• Reco comparison results: 43 differences found in the comparisons
• DQMHistoTests: Total files compared: 48
• DQMHistoTests: Total histograms compared: 3248620
• DQMHistoTests: Total failures: 3
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3248595
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 47 files compared)
• Checked 200 log files, 161 edm output root files, 48 DQM output files
• TriggerResults: no differences found