Fix copying of Attendees Uri-typed properties (#643)

* Fix cloning of Attendee, where we didn't preserve the Uri properties' `OriginalStrin` value.

* Test: Adjust AttendeesSerialized to the implemented behavior of `Attendee`, which is to keep the casing of the `Uri` typed properties, even if not in line with the RFC.

Author: minichma

Ical.Net.Tests/SerializationTests.cs

@@ -314,8 +314,8 @@ public void AttendeesSerialized()
 
         var evt = AttendeeTest.VEventFactory();
         cal.Events.Add(evt);
-        // new Uri() creates lowercase for the "MAILTO:" part
-        // according to the RFC 2368 specification
+        // The casing of `MAILTO` is not in line with RFC 2368, but we should
+        // be able to deal with it nevertheless and preserve it the way it is.
         const string org = "MAILTO:[email protected]";
         evt.Organizer = new Organizer(org);
 
@@ -331,7 +331,7 @@ public void AttendeesSerialized()
 
         foreach (var a in evt.Attendees)
         {
-            var vals = GetValues(vEvt, "ATTENDEE", a.Value.ToString());
+            var vals = GetValues(vEvt, "ATTENDEE", a.Value.OriginalString.ToString());
             foreach (var v in new Dictionary<string, string>
                      {
                          ["CN"] = a.CommonName,

Ical.Net/DataTypes/Attendee.cs

@@ -253,7 +253,7 @@ public override void CopyFrom(ICopyable obj)
         if (obj is not Attendee atn) return;
         base.CopyFrom(obj);
 
-        Value = new Uri(atn.Value.ToString());
+        Value = atn.Value;
 
         // String assignments create new instances
         CommonName = atn.CommonName;
@@ -263,8 +263,8 @@ public override void CopyFrom(ICopyable obj)
 
         Rsvp = atn.Rsvp;
 
-        SentBy = atn.SentBy != null ? new Uri(atn.SentBy.ToString()) : null;
-        DirectoryEntry = atn.DirectoryEntry != null ? new Uri(atn.DirectoryEntry.ToString()) : null;
+        SentBy = atn.SentBy;
+        DirectoryEntry = atn.DirectoryEntry;
     }
 
     protected bool Equals(Attendee other) => Equals(SentBy, other.SentBy)