Affects Version/s: None
Fix Version/s: None
Component/s: Data Binder
FLUID-5585 covered a wide range of cases of relaying partial or complete DELETE changes, we've failed to cover an obvious case of "removal through ADD" - it is perfectly possible that a relay rule on receiving an ADD change at some terminal may relay this to its target as a shrinkage of previously visible model material - requiring a DELETE of some kind in order to honour it.
This was encountered in work on at https://github.com/GPII/universal/pull/549 for https://issues.gpii.net/browse/GPII-2556. Here we had a complex free transform which relayed a preference set onto a collection of visible controls.
Depending on the exact order in which model changes occurred within the ContextManager, it was possible for this rule to leave the output model as
a combination of the old and new model state, rather than the expected contents of
which just includes one control output.