Minor bug fix in Delta Finder

[michaelmackenzie]

This fixes the bugs pointed out in issue #1804.

[FNALbuild]

Hi @michaelmackenzie,
You have proposed changes to files in these packages:

• CalPatRec

which require these tests: build.

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⌛ The following tests have been triggered for d9ca12d: build (Build queue - API unavailable)

About FNALbuild. Code review on Mu2e/Offline.

[FNALbuild]

☀️ The build tests passed at d9ca12d.

Test	Result	Details
test with	✅	Command did not list any other PRs to include
merge	✅	Merged d9ca12d at 95f0a83
build (prof)	✅	Log file. Build time: 04 min 12 sec
ceSimReco	✅	Log file.
g4test_03MT	✅	Log file.
transportOnly	✅	Log file.
POT	✅	Log file.
g4study	✅	Log file.
cosmicSimReco	✅	Log file.
cosmicOffSpill	✅	Log file.
ceSteps	✅	Log file.
ceDigi	✅	Log file.
muDauSteps	✅	Log file.
ceMix	✅	Log file.
rootOverlaps	✅	Log file.
g4surfaceCheck	✅	Log file.
trigger	❓	Log file. Return Code 1.
check_cmake	✅	Log file.
FIXME, TODO	➡️	TODO (2) FIXME (7) in 1 files
clang-tidy	➡️	2 errors 98 warnings
whitespace check	✅	no whitespace errors found

N.B. These results were obtained from a build of this Pull Request at d9ca12d after being merged into the base branch at 95f0a83.

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[oksuzian]

Review: PR #1831 — Minor bug fix in Delta Finder

This is a 3-line bug fix in CalPatRec/src/DeltaFinderAlg.cc correcting copy-paste errors. All changes look correct and address real bugs.

🔴 Critical Issues — None

🟡 Suggestions — None beyond what's already done

Summary of fixes (all correct):

• DeltaFinderAlg.cc:597 — Fixes y1 = dc1->Xc() → dc1->Yc(). Genuine copy-paste bug; y1 was getting the x-coordinate, corrupting any subsequent delta-candidate distance/pairing logic.
• DeltaFinderAlg.cc:793 — Fixes chi2_ds2 = ds1->Chi2TotN()+ds1->Chi2Time() → ds2->.... The variable is named for ds2 and used to flag ds2 as bad (fGood = -1000-i2); previously the inner seed was being culled based on the outer seed's chi². Clear bug, correct fix.
• DeltaFinderAlg.cc:311 — 1 → 1. in q12 = 1.-w1w2*w1w2. Cosmetic; w1w2*w1w2 is already double, so the original 1 promotes correctly. No behavior change, but consistent with the surrounding style.

Verdict

LGTM. Both substantive fixes are correct and address the bugs reported in #1804. None of the review areas (art contracts, Proditions, Geant4 MT, TFileService, fhicl, CLHEP units) are touched. Safe to merge.

[FNALbuild]

📝 The HEAD of main has changed to 23fc715. Tests are now out of date.