[Servicing 3.1] [Accessibility] DefaultAction is empty for Combobox when "LegacyIAccessible" pattern is supported and Accessible Role is changed.

[SergeySmirnov-Akvelon]

.NET Core Version: 3.1
Have you experienced this same bug with .NET Framework?: No

Problem description:
The DefaultAction is empty for Combobox when role is default and "LegacyIAccessible" pattern is supported.
The DefaultAction stays empty if change the Role property value and "LegacyIAccessible" pattern is supported.

Expected behavior:
The DefaultAction should be "Expand" for Combobox when role is default and "LegacyIAccessible" pattern is supported.
The DefaultAction property should be changed when Accessible Role is changed.

Minimal repro:

1. Add supporting of "LegacyIAccessible" pattern for Combobox
2. Create a .Net 5.0 app
3. Add a Combobox to the app form
4. Run the app and check "DefaultAction" property using Inspect

[Tanya-Solyanik]

@Olina-Zhang - could you please see if this bug repros on .NET 7.0. If it does not repro, I suggest we close this bug as we have no request for servicing. Thanks

[Olina-Zhang]

@Tanya-Solyanik how to add supporting of "LegacyIAccessible" pattern for Combobox described in above step1? I verified it cannot repro in .Net core 3.1 and 7.0 if skip it.

[vladimir-krestov]

We can't set LegacyIAccessible outside. So, if it can't repro, let's close the issue.