AthLinks: Fix for initializing EL from default DL.

When we initialize an ElementLink from a default DataLink, make sure the EL also ends up in the default state (thus ignoring any index that was provided).

This merge request affects 1 package:

• Control/AthLinks

This merge request affects 4 files:

• Control/AthLinks/AthLinks/ElementLinkBase.icc
• Control/AthLinks/AthLinks/GenericElementLinkBase.icc
• Control/AthLinks/test/ElementLinkBase_test.cxx
• Control/AthLinks/test/GenericElementLinkBase_test.cxx

Adding @ssnyder as watcher

added Core main review-pending-level-1 labels

added full-integration-tests full-unit-tests labels

CI Result SUCCESS (hash 8cecab57)

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 1947]

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

merged

mentioned in commit a085ed8b