MergedOptions Instance can be null on attempted access

[keegan-caruso]

Microsoft.Identity.Web Library

Microsoft.Identity.Web

Microsoft.Identity.Web version

3.8.3

Web app

Not Applicable

Web API

Not Applicable

Token cache serialization

Not Applicable

Description

When "PrepareAuthorityForMsal" is called, Instance needs to be ensured that it is non-null

microsoft-identity-web/src/Microsoft.Identity.Web.TokenAcquisition/MergedOptions.cs

Line 476 in 09a9a62

if (IsB2C && Instance.EndsWith("/tfp/", StringComparison.OrdinalIgnoreCase))

Reproduction steps

NA

Error message

Possible NRE

Id Web logs

No response

Relevant code snippets

NA

Regression

No response

Expected behavior

Ensure string is not null