Core: DistanceRangeMap.putMany() doesn't merge equal values for consecutive intervals

[bougue-pe]

What happened?

See tests in /~https://github.com/osrd-project/osrd/compare/peb/core/fix_distance_range_put_many
The merge when extremities and values are the same is not done by putMany(), leading to a different behavior than expected, and than put().

What did you expect to happen?

Have putMany() merging consecutive ranges with identical values.

How can we reproduce it (as minimally and precisely as possible)?

Use tests available in peb/core/fix_distance_range_put_many branch

What operating system, browser and environment are you using?

• WSL
• Gradle
• Java 17

OSRD version (top right corner Account button > Informations)

dfcbaad

[shenriotpro]

IMO the main issue is that putMany considers equal bounds separately /~https://github.com/osrd-project/osrd/blob/ac93bc8040d8e558a2f5350ad022ee347772df2e/core/kt-osrd-utils/src/main/kotlin/fr/sncf/osrd/utils/DistanceRangeMapImpl.kt#L60

We could use mergeAdjacent for a quick fix, but I think it would be more efficient/readable to group bounds in putMany.
We may also want to split the logic in two parts: e.g. the first part handles groups (removes empty intervals) and the second part merges adjacent intervals with the same value.