[Bug Bash] New added package source mapping will lost after switching back to the "Package Source Mapping" tab from other tab in “Option->NuGet Package Manager” window

[CiciLi1]

NuGet Product Used

Visual Studio Package Management UI

Product Version

NuGet Client Dev\6.9.0.85

Worked before?

No response

Impact

It bothers me. A fix would be nice

Repro Steps & Context

Repro Steps:       

1. Create a .NET Core Console App project via VS.
2. Right-click the project in Solution Explorer and select ‘Manage NuGet Packages…’ menu item to open PM UI.
3. Click the “settings” button on the right panel and click “Package Source Mapping” tab.
4. Click “Add” button, type a string (e.g. “Microsoft”) in the package pattern textbox and select a package source in the source.
5. Click “Add” button on the bottom.
6. Click another tab (for example: “Package Sources” tab).
7. Switch back to “Package mapping Source” tab.

Expected:     

The new added package source mapping (in step5) should be still in the list.

Actual:        

The new added package source mapping lost as the record below. 

Notes:    

1.The repro rate is 100%.  
2.This is not a regression since it is a new feature.    
3. The issue doesn’t repro in “Package Sources” tab.

Verbose Logs

No response

[donnie-msft]

Thanks for calling this out! I do think it can be improved. What happens is the page loads mappings from disk every time it's opened. It seems the way VS Options should work is that state is maintained across page switches. An interesting note: after changing source mappings, navigating to another options page, then pressing OK, the package source mappings are indeed persisted. That's because only when reopening the page does it reload from disk.

A less preferred but acceptable option would be to warn the customer that changes may be lost when navigating away.

[SueSu01]

It still reproes on VS Main\35222.175 + NuGet Client Dev\6.12.0.82.