Sweeping !32124 from 21.3 to 21.9. Fix MMOverlay bug causing crashes

Fix MMOverlay bug causing crashes

See merge request !32124 (merged)

added sweep:from 21.3 label

Adding original author @alaurier as watcher.

This merge request affects 1 package:

• MuonSpectrometer/MuonOverlay/MM_Overlay

Adding @jchapman ,@rosati ,@wleight ,@tkharlam ,@tadej ,@nkoehler ,@ahaas as watchers

added 21.9 MuonSpectrometer Overlay review-pending-level-1 labels

CI Result SUCCESS (hash 94cb92fb)

	Athena
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 156
For experts only: Jenkins output [CI-MERGE-REQUEST 43536]

The CI looks messy, but the warnings are unrelated to this.

MLB (L1)

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit fa6f8c52

added sweep:ignore label