integrate `DescriptorIndexCollector` in a fully backward-compatible way
Adapt the alpha implementation from release 1.4.0, ticket #19791 (moved).
See comments 10 to 12 in #19791 (moved) for background.
Adapt the alpha implementation from release 1.4.0, ticket #19791 (moved).
See comments 10 to 12 in #19791 (moved) for background.