UBSAN: Fixing improper cast to RectangularPixelTopology

[smuzaffar]

This PR proposes to drop the explicit improper cast to RectangularPixelTopology. With Phase2 geometry

const PixelTopology* theSpecificTopology = &(detUnit->specificType().specificTopology());

is RectangularPixelPhase2Topology instead of RectangularPixelTopology . Existing code explicitly casts it to RectangularPixelTopology. See #50664 where UBSAN IBs reports this runtime issue/error.

As all the baseclass member functions called via rectPixelTopology are overridden in RectangularPixelTopology and RectangularPixelPhase2Topology so there is no need of explicit cast. One should be able to just use the base pointer to PixelTopology

Fixes #50664

[cmsbuild]

cms-bot internal usage

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-50883/49236

[cmsbuild]

A new Pull Request was created by @smuzaffar for master.

It involves the following packages:

• FastSimulation/TrackingRecHitProducer (fastsim)

@civanch, @cmsbuild, @kpedro88, @mdhildreth, @ssekmen can you please review it and eventually sign? Thanks.
@matt-komm, @sbein this is something you requested to watch as well.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[smuzaffar]

please test

[smuzaffar]

please test workflow 36434.0 with #50882 for CMSSW_17_0_UBSAN_X

[cmsbuild]

+1

Size: This PR adds an extra 28KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-a33227/53081/summary.html
COMMIT: 309d7a1
CMSSW: CMSSW_17_0_X_2026-05-05-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/50883/53081/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially removed 3 lines from the logs
• Reco comparison results: 20 differences found in the comparisons
• DQMHistoTests: Total files compared: 55
• DQMHistoTests: Total histograms compared: 4420967
• DQMHistoTests: Total failures: 26
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4420921
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 54 files compared)
• Checked 235 log files, 207 edm output root files, 55 DQM output files
• TriggerResults: no differences found

[kpedro88]

+fastsim

[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. @sextonkennedy, @ftenchini, @mandrenguyen (and backports should be raised in the release meeting by the corresponding L2)
Notice This PR was tested with additional Pull Request(s), please also merge them if necessary: #50882

[cmsbuild]

-1

Failed Tests: UnitTests
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-a33227/53082/summary.html
COMMIT: 309d7a1
CMSSW: CMSSW_17_0_UBSAN_X_2026-05-04-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/50883/53082/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:

• @smuzaffar Fix hlt-p2-timing: properly wait and comsume the background processed #50868
• @cms-tsg-storm HLT menu development for 16_0_X (6/N) [17_0_X] #50877
• @jhakala [HCAL] fix bug that was causing filter to miss stuck digis  #50857
• @SegmentLinking LST: Remove Matrix Caps for MDs using Precompute #50856
• @Dr15Jones Ignore Io_v1 when generating the class friendly name #50854
• @gartung PerfTools/AllocMonitor: Add additional transition types to moduleAllocMonitor circles json. #50822
• @CMS-HGCAL HD full module readout corrected #50644

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-a33227/53082/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-a33227/53082/git-merge-result

Failed Unit Tests

I found 1 errors in the following unit tests:

---> test testIntrusiveAllocMonitorOutput had ERRORS

[smuzaffar]

https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-a33227/53082/runTheMatrix-results/36434.0_TTbar_14TeV+Run4D110FS/step2_TTbar_14TeV+Run4D110FS.log shows that there are no more runtime error for improper cast to RectangularPixelTopology . There are couple of more runtime errors but those can be fixed in separate PR