Register-PackageSource: Doesn't save credentials to `nuget.config` file

[SetTrend]

Current Behavior

When I enter …

Register-PackageSource -Name 'Test' -Location 'https://test.contoso.com/' -ProviderName 'NuGet' -Credential (Get-Credential) -ForceBootstrap -Trusted

… no credentials are getting saved to the nuget.config file.

Expected Behavior

If the Credential argument is provided with ProviderName being "NuGet", Register-PackageSource should save provided credentials to nuget.config file.

[SetTrend]

As a side note: The password should be stored encrypted in the nuget.config file. Providing an additional argument -AsPlainText, however, the credentials should be stored unencrypted, in plain text.