HttpListenerRequest.UserAgent is nullable
The HttpListenerRequest.UserAgent property was previously annotated as being non-nullable, but it was actually nullable in practice. The nullable annotation for this properties has been updated to indicate that it's nullable. This can result in new build warnings related to use of nullable members.
Previous behavior
Previously, the property was annotated as not being nullable. You could consume its value and assume it could not be null without getting any warnings during build.
New behavior
Starting in .NET 9, the property is annotated as being nullable. If you consume the value without checking for null, you'll get a build warning.
Version introduced
.NET 9 Preview 1
Type of breaking change
This change can affect source compatibility.
Reason for change
The annotations of this property was incorrect. This change applies the appropriate behavior for the property and ensures callers understand the value can be null.
Recommended action
Update calling code to guard against null for this property.
