||Lisa, thanks for your reply.
To bring anyone following this thread up to speed, I'll relay the responses I've received directly from ERSI tech support.
This was their first response from 6/14:
"The behavior that 'worked' at 9.1 and earlier was unintended; the Cut Polygons task was not designed with this workflow in mind. We changed the implementation of Cut Polygon Features at 9.2 to address some problems with supported workflows, which inadvertently changed the behavior documented here.
The issue is an example of a workflow that worked incorrectly or not by design. During this time, some users have become accustomed to this workflow. When the issue had become fixed and resolved for ArcGIS 9.2, some users misunderstood the original behavior of the function.
Currently, the Cut Polygon Features is working correctly and as designed for ArcGIS 9.2."
Given that their opinion was that this workflow for selectively splitting off polygons from a multi-part was, in effect, "doing it wrong", I then asked them to explain what they thought was the way to "do it right". This is when NIM009428 was created. Before Lisa's response above was submitted, tech support sent me this message on 6/21:
"As a result of the change in functionality at 9.2, I've created an enhancement request regarding this issue. It details the prior functionality, what changed, and the current workaround which is less then ideal. Please use the following enhancement request to track this issue -> NIM009849.
I would also encourage you to touch base with your ESRI sales rep in regards to the importance that issue be addressed.
The only way we can see to go about this via the GUI is to do an explode on the multi feature, then a merge the polygons back together that you didn't intend to split away.
Something like this could also be done through code, however, management of the attributes would have to also be managed. Please let me know if you need any help getting started with this."
This reponse correctly identifies the problem with Lisa's developer sample workaround: field management using attribute domains. Lisa's developer sample code simply uses a boiler-plate loop for copying field values verbatim from the existing multi-part feature to the newly created feature. The user is made to become responsible for manually managing any Split/Merge policies defined in a personal geodatabase domain and applied to a feature class field. This renders Split/Merge domain policies ineffective: if they only work on actions which respond to the IFeatureEdit::Split method, and we're being asked to use an alternative to IFeatureEdit::Split in some situations, then attribute domains are unreliable for handling edits in our geodatabases.
I guess it's not surprising that a similar issue came up in the implementation of Topology editing tools:
This is a step backward. The workflow used before 9.2 for splitting multi-part polygons ensured that attribute domains successfully managed field values in the broken up parts. However ESRI is telling us this workflow was wrong. If their solution is to have us use a workflow that does not allow any attribute domain to perform its function, are we not also being told that we shouldn't be using attribute domains? Have attribute domains themselves "become fixed and resolved for ArcGIS 9.2" since their usefulness in 9.1 and below were "an example of a workflow that worked incorrectly or not by design"?
If not, many users out there could use generic, polymorphic sample code for manually managing field updates such that attribute domains are looked for and obeyed if present. I'll take that sample and overhaul the code in my polygon feature class editing events to handle this situation manually until the "enhancement" (which is a return to the way things were before 9.2) request is fulfilled.