From 5882b1ab3f409f52cd165d00666c852aff1121d9 Mon Sep 17 00:00:00 2001
From: Kamron Batman <3953314+kamronbatman@users.noreply.github.com>
Date: Fri, 8 Jan 2021 23:55:23 -0800
Subject: [PATCH] fix(core): Fixes OPL packets (#395)

- [X] Fixes an issue with OPL packets using the wrong endianness and not updating the position properly.
- [X] Fixes an issue with SpanWriter not updating bytes written when it is used adhoc.
- [X] Moves packet creation for OPL inside the SendInfoTo function.

Bumps release version
---
 Projects/Server/Buffers/SpanWriter.cs                  |  2 +-
 Projects/Server/Items/Item.cs                          |  9 +++++++--
 .../Server/Network/Packets/IncomingEntityPackets.cs    |  2 ++
 Projects/Server/ObjectPropertyList.cs                  | 10 +++++-----
 Projects/UOContent/Items/Misc/Corpses/Corpse.cs        |  2 +-
 Projects/UOContent/Multis/HouseFoundation.cs           |  2 +-
 6 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/Projects/Server/Buffers/SpanWriter.cs b/Projects/Server/Buffers/SpanWriter.cs
index 73740af99..7ca8952e5 100644
--- a/Projects/Server/Buffers/SpanWriter.cs
+++ b/Projects/Server/Buffers/SpanWriter.cs
@@ -365,7 +365,7 @@ namespace System.Buffers
                 Grow(newPosition - _buffer.Length + 1);
             }
 
-            return _position = newPosition;
+            return Position = newPosition;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
diff --git a/Projects/Server/Items/Item.cs b/Projects/Server/Items/Item.cs
index c62a1d360..e078aa692 100644
--- a/Projects/Server/Items/Item.cs
+++ b/Projects/Server/Items/Item.cs
@@ -1152,7 +1152,7 @@ namespace Server
                     Span<byte> opl = ObjectPropertyList.Enabled ? stackalloc byte[OutgoingEntityPackets.OPLPacketLength] : null;
                     if (opl != null)
                     {
-                        OutgoingEntityPackets.CreateOPLInfo(opl, this);
+                        opl.InitializePacket();
                     }
 
                     var eable = m_Map.GetClientsInRange(m_Location, GetMaxUpdateRange());
@@ -3094,8 +3094,13 @@ namespace Server
 
         public virtual int GetUpdateRange(Mobile m) => 18;
 
-        public virtual void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, ReadOnlySpan<byte> opl = default)
+        public virtual void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, Span<byte> opl)
         {
+            if (opl != null && opl[0] == 0)
+            {
+                OutgoingEntityPackets.CreateOPLInfo(opl, this);
+            }
+
             SendWorldPacketTo(ns, world);
             SendOPLPacketTo(ns, opl);
         }
diff --git a/Projects/Server/Network/Packets/IncomingEntityPackets.cs b/Projects/Server/Network/Packets/IncomingEntityPackets.cs
index ab629a83f..d2ebe2af8 100644
--- a/Projects/Server/Network/Packets/IncomingEntityPackets.cs
+++ b/Projects/Server/Network/Packets/IncomingEntityPackets.cs
@@ -13,6 +13,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  *************************************************************************/
 
+using System;
+
 namespace Server.Network
 {
     public static class IncomingEntityPackets
diff --git a/Projects/Server/ObjectPropertyList.cs b/Projects/Server/ObjectPropertyList.cs
index 55d7d4aeb..5092e0173 100644
--- a/Projects/Server/ObjectPropertyList.cs
+++ b/Projects/Server/ObjectPropertyList.cs
@@ -117,19 +117,19 @@ namespace Server
                 AddHash(arguments.GetHashCode(StringComparison.Ordinal));
             }
 
-            int strLength = Utility.Unicode.GetByteCount(arguments);
-
+            int strLength = arguments.Length * 2;
             int length = _position + 6 + strLength;
             while (length > _buffer.Length)
             {
                 Flush();
             }
 
-            var writer = new SpanWriter(_buffer);
-            writer.Seek(_position, SeekOrigin.Begin);
+            var writer = new SpanWriter(_buffer.AsSpan(_position));
             writer.Write(number);
             writer.Write((ushort)strLength);
-            writer.WriteBigUni(arguments);
+            writer.WriteLittleUni(arguments);
+
+            _position += writer.BytesWritten;
         }
 
         public void Add(int number, string format, object arg0)
diff --git a/Projects/UOContent/Items/Misc/Corpses/Corpse.cs b/Projects/UOContent/Items/Misc/Corpses/Corpse.cs
index 94df03186..c8593bcc8 100644
--- a/Projects/UOContent/Items/Misc/Corpses/Corpse.cs
+++ b/Projects/UOContent/Items/Misc/Corpses/Corpse.cs
@@ -825,7 +825,7 @@ namespace Server.Items
             }
         }
 
-        public override void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, ReadOnlySpan<byte> opl = default)
+        public override void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, Span<byte> opl)
         {
             base.SendInfoTo(ns, world, opl);
 
diff --git a/Projects/UOContent/Multis/HouseFoundation.cs b/Projects/UOContent/Multis/HouseFoundation.cs
index 4869d67ab..fd05b69ad 100644
--- a/Projects/UOContent/Multis/HouseFoundation.cs
+++ b/Projects/UOContent/Multis/HouseFoundation.cs
@@ -888,7 +888,7 @@ namespace Server.Multis
             stateToSend.SendGeneralInfoTo(ns);
         }
 
-        public override void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, ReadOnlySpan<byte> opl = default)
+        public override void SendInfoTo(NetState ns, ReadOnlySpan<byte> world, Span<byte> opl)
         {
             base.SendInfoTo(ns, world, opl);