feat(core): Makes spanwriter resizable (#376)

SpanWriter now has an argument that allows it to be resizable.
```cs
public SpanWriter(Span<byte> initialBuffer, bool resize = false)
public SpanWriter(int initialCapacity, bool resize = false)
```

If a SpanWriter is set to be resizable, or given an initial capacity instead of a buffer, it must be disposed:
```cs
public static void SomeMethod()
{
    using var writer = new SpanWriter(stackalloc byte[512], true);
    // stuff
    
    // Automatic Dispose of writer
}
```

This is because the SpanWriter uses `ArrayPool<byte>.Shared` _rented buffers_ to resize. If the writer is not disposed, those buffers will never be reused resulting in a _memory leak_.

It is possible that the SpanWriter will outright ditch the initial buffer if resize is set to true and growing is needed. To check/account for that we can do the following:

```cs
public static void SomeMethod()
{
    Span<byte> span = stackalloc byte[512];
    using var writer = new SpanWriter(span, true);
    // write some stuff that causes the span to grow
    
    span = writer.RawBuffer;
    // Do stuff with the span
}
```

Make sure you don't accidentally `Dispose()` the writer or use the `RawBuffer` outside of the `using` block. If you do, bad things will happen! (NullPointerException, or a fresh SpanWriter with no buffer, depending on the situation).

SpanWriter can also now be used with a fixed statement since it has a `PinnableReference()` function.

Directory.Build.props

@@ -52,14 +52,7 @@
         <AnalysisLevel>latest</AnalysisLevel>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="Nerdbank.GitVersioning" Version="3.3.37">
+        <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.165-alpha">
-            <PrivateAssets>all</PrivateAssets>
-            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-        </PackageReference>
-    </ItemGroup>
-    <ItemGroup Condition="'$(Configuration)'=='Analyze'">
-        <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers">
-            <Version>3.3.1</Version>
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>

Projects/Server.Tests/Server.Tests.csproj

@@ -3,7 +3,7 @@
         <IsPackable>false</IsPackable>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.0-preview-20201123-03" />
         <PackageReference Include="xunit" Version="2.4.1" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
         <PackageReference Include="coverlet.collector" Version="1.3.0" />

Projects/Server.Tests/Tests/Buffers/SpanWriterTests.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Buffers;
+using Xunit;
+
+namespace Server.Tests
+{
+    public class SpanWriterTests
+    {
+        [Fact]
+        public unsafe void TestSpanWriterResizes()
+        {
+            Span<byte> smallStack = stackalloc byte[8];
+            using var writer = new SpanWriter(smallStack, true);
+            writer.Write(0x1024L);
+            writer.Write(0x1024L);
+
+            var span = writer.RawBuffer;
+            fixed (byte* spanPtr = span)
+            {
+                fixed (byte* stackPtr = smallStack)
+                {
+                    Assert.True(spanPtr != stackPtr);
+                }
+            }
+
+            Assert.True(span.Length > smallStack.Length);
+        }
+
+        [Fact]
+        public unsafe void TestSpanWriterOnlyStackAlloc()
+        {
+            Span<byte> smallStack = stackalloc byte[8];
+            using var writer = new SpanWriter(smallStack, true);
+            writer.Write(0x1024L);
+
+            var span = writer.RawBuffer;
+            fixed (byte* spanPtr = span)
+            {
+                fixed (byte* stackPtr = smallStack)
+                {
+                    Assert.True(spanPtr == stackPtr);
+                }
+            }
+
+            Assert.True(span.Length == smallStack.Length);
+            AssertThat.Equal(smallStack, stackalloc byte[] { 0, 0, 0, 0, 0, 0, 0x10, 0x24 });
+        }
+
+        [Fact]
+        public void TestSpanWriterNoResizeThrows()
+        {
+            Assert.Throws<OutOfMemoryException>(
+                () =>
+                {
+                    Span<byte> smallStack = stackalloc byte[8];
+                    using var writer = new SpanWriter(smallStack);
+                    writer.Write(0x1024L);
+                    writer.Write(0x1024L);
+                }
+            );
+        }
+    }
+}

Projects/Server/Buffers/CircularBufferReader.cs

@@ -370,7 +370,7 @@ namespace Server.Network
             Position = origin switch
             {
                 SeekOrigin.Begin => offset,
-                SeekOrigin.End   => Length - offset,
+                SeekOrigin.End   => Length + offset,
                 _                => Position + offset // Current
             };
     }

Projects/Server/Buffers/CircularBufferWriter.cs

@@ -528,7 +528,7 @@ namespace System.Buffers
             Position = origin switch
             {
                 SeekOrigin.Begin => offset,
-                SeekOrigin.End   => Length - offset,
+                SeekOrigin.End   => Length + offset,
                 _                => Position + offset // Current
             };
     }

Projects/Server/Buffers/SpanReader.cs

@@ -14,6 +14,7 @@
  *************************************************************************/
 
 using System.Buffers.Binary;
+using System.Diagnostics;
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Text;
@@ -176,12 +177,44 @@ namespace System.Buffers
         public string ReadAscii() => ReadString(Encoding.ASCII);
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public int Seek(int offset, SeekOrigin origin) =>
+        public int Seek(int offset, SeekOrigin origin)
-            Position = origin switch
+        {
+            Debug.Assert(
+                origin != SeekOrigin.End || offset <= 0,
+                "Attempting to seek to a position beyond capacity using SeekOrigin.End"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.End || offset >= -_buffer.Length,
+                "Attempting to seek to a negative position using SeekOrigin.End"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Begin || offset >= 0,
+                "Attempting to seek to a negative position using SeekOrigin.Begin"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Begin || offset <= _buffer.Length,
+                "Attempting to seek to a position beyond the capacity using SeekOrigin.Begin"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Current || Position + offset >= 0,
+                "Attempting to seek to a negative position using SeekOrigin.Current"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Current || Position + offset <= _buffer.Length,
+                "Attempting to seek to a position beyond the capacity using SeekOrigin.Current"
+            );
+
+            return Position = Math.Max(0, origin switch
             {
-                SeekOrigin.Begin => offset,
+                SeekOrigin.Current => Position + offset,
-                SeekOrigin.End   => Length - offset,
+                SeekOrigin.End     => _buffer.Length + offset,
-                _                => Position + offset // Current
+                _                  => offset // Begin
-            };
+            });
+        }
     }
 }

Projects/Server/Buffers/SpanWriter.cs

@@ -15,8 +15,10 @@
 
 using System.Buffers.Binary;
 using System.Data;
+using System.Diagnostics;
 using System.IO;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 using Server;
 
@@ -24,122 +26,173 @@ namespace System.Buffers
 {
     public ref struct SpanWriter
     {
-        private readonly Span<byte> _buffer;
+        private readonly bool _resize;
+        private byte[]? _arrayToReturnToPool;
+        private Span<byte> _buffer;
+        private int _position;
 
-        public int Length => _buffer.Length;
+        public int Length { get; private set; }
+
+        public int Position
+        {
+            get => _position;
+            private set
+            {
+                _position = value;
+
+                if (value > Length)
+                {
+                    Length = value;
+                }
+            }
+        }
+
+        public int Capacity => _buffer.Length;
 
         public ReadOnlySpan<byte> Span => _buffer.Slice(0, Position);
 
-        public int Position { get; private set; }
+        public Span<byte> RawBuffer => _buffer;
 
-        public SpanWriter(Span<byte> span)
+        public SpanWriter(Span<byte> initialBuffer, bool resize = false)
         {
-            _buffer = span;
+            _resize = resize;
-            Position = 0;
+            _buffer = initialBuffer;
+            _position = 0;
+            Length = 0;
+            _arrayToReturnToPool = null;
+        }
+
+        public SpanWriter(int initialCapacity, bool resize = false)
+        {
+            _resize = resize;
+            _arrayToReturnToPool = ArrayPool<byte>.Shared.Rent(initialCapacity);
+            _buffer = _arrayToReturnToPool;
+            _position = 0;
+            Length = 0;
+        }
+
+        [MethodImpl(MethodImplOptions.NoInlining)]
+        private void Grow(int additionalCapacity)
+        {
+            var newSize = Math.Max(Length + additionalCapacity, _buffer.Length * 2);
+            byte[] poolArray = ArrayPool<byte>.Shared.Rent(newSize);
+
+            _buffer.Slice(0, Length).CopyTo(poolArray);
+
+            byte[]? toReturn = _arrayToReturnToPool;
+            _buffer = _arrayToReturnToPool = poolArray;
+            if (toReturn != null)
+            {
+                ArrayPool<byte>.Shared.Return(toReturn);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void GrowIfNeeded(int count)
+        {
+            if (_position + count > _buffer.Length)
+            {
+                if (!_resize)
+                {
+                    throw new OutOfMemoryException();
+                }
+
+                Grow(count);
+            }
+        }
+
+        public ref byte GetPinnableReference() => ref MemoryMarshal.GetReference(_buffer);
+
+        public void EnsureCapacity(int capacity)
+        {
+            if (capacity > _buffer.Length)
+            {
+                if (!_resize)
+                {
+                    throw new OutOfMemoryException();
+                }
+
+                Grow(capacity - Length);
+            }
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public unsafe void Write(bool value)
         {
-            if (Position >= Length)
+            GrowIfNeeded(1);
-            {
+            _buffer[Position++] = *(byte*)&value;
-                throw new OutOfMemoryException();
-            }
-
-            _buffer[Position++] = *(byte*) & value;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(byte value)
         {
+            GrowIfNeeded(1);
             _buffer[Position++] = value;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(sbyte value)
         {
+            GrowIfNeeded(1);
             _buffer[Position++] = (byte)value;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(short value)
         {
-            if (!BinaryPrimitives.TryWriteInt16BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(2);
-            {
+            BinaryPrimitives.WriteInt16BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 2;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(ushort value)
         {
-            if (!BinaryPrimitives.TryWriteUInt16BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(2);
-            {
+            BinaryPrimitives.WriteUInt16BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 2;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(int value)
         {
-            if (!BinaryPrimitives.TryWriteInt32BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(4);
-            {
+            BinaryPrimitives.WriteInt32BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 4;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(uint value)
         {
-            if (!BinaryPrimitives.TryWriteUInt32BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(4);
-            {
+            BinaryPrimitives.WriteUInt32BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 4;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(long value)
         {
-            if (!BinaryPrimitives.TryWriteInt64BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(8);
-            {
+            BinaryPrimitives.WriteInt64BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 8;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Write(ulong value)
         {
-            if (!BinaryPrimitives.TryWriteUInt64BigEndian(_buffer.Slice(Position), value))
+            GrowIfNeeded(8);
-            {
+            BinaryPrimitives.WriteUInt64BigEndian(_buffer.Slice(_position), value);
-                throw new OutOfMemoryException();
-            }
-
             Position += 8;
         }
 
         public void Write(ReadOnlySpan<byte> buffer)
         {
-            var size = buffer.Length;
+            var count = buffer.Length;
-            if (Position + size > Length)
+            GrowIfNeeded(count);
-            {
+            buffer.CopyTo(_buffer.Slice(_position));
-                throw new OutOfMemoryException();
+            Position += count;
-            }
-
-            buffer.Slice(0, size).CopyTo(_buffer.Slice(Position));
-            Position += size;
         }
 
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void WriteString<T>(string value, Encoding encoding, int fixedLength = -1) where T : struct, IEquatable<T>
         {
             int sizeT = Unsafe.SizeOf<T>();
@@ -156,12 +209,9 @@ namespace System.Buffers
 
             var byteCount = fixedLength > -1 ? fixedLength * sizeT : encoding.GetByteCount(value);
 
-            if (Position + byteCount > Length)
+            GrowIfNeeded(byteCount);
-            {
-                throw new OutOfMemoryException();
-            }
 
-            var bytesWritten = encoding.GetBytes(src, _buffer.Slice(Position));
+            var bytesWritten = encoding.GetBytes(src, _buffer.Slice(_position));
             Position += bytesWritten;
 
             if (fixedLength > -1)
@@ -194,7 +244,7 @@ namespace System.Buffers
         public void WriteBigUniNull(string value)
         {
             WriteString<char>(value, Utility.Unicode);
-            Write((ushort)0);
+            Write((ushort)0); // '\0'
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -207,7 +257,7 @@ namespace System.Buffers
         public void WriteUTF8Null(string value)
         {
             WriteString<byte>(value, Utility.UTF8);
-            Write((byte)0);
+            Write((byte)0); // '\0'
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -217,38 +267,77 @@ namespace System.Buffers
         public void WriteAsciiNull(string value)
         {
             WriteString<byte>(value, Encoding.ASCII);
-            Write((byte)0);
+            Write((byte)0); // '\0'
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void WriteAscii(string value, int fixedLength) => WriteString<byte>(value, Encoding.ASCII, fixedLength);
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Clear()
+        public void Clear(int count)
         {
-            _buffer.Slice(Position).Clear();
+            GrowIfNeeded(count);
-            Position = Length;
+            _buffer.Slice(_position, count).Clear();
+            Position += count;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void Clear(int amount)
+        public int Seek(int offset, SeekOrigin origin)
         {
-            if (Position + amount > Length)
+            Debug.Assert(
+                origin != SeekOrigin.End || _resize || offset <= 0,
+                "Attempting to seek to a position beyond capacity using SeekOrigin.End without resize"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.End || offset >= -_buffer.Length,
+                "Attempting to seek to a negative position using SeekOrigin.End"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Begin || offset >= 0,
+                "Attempting to seek to a negative position using SeekOrigin.Begin"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Begin || _resize || offset <= _buffer.Length,
+                "Attempting to seek to a position beyond the capacity using SeekOrigin.Begin without resize"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Current || _position + offset >= 0,
+                "Attempting to seek to a negative position using SeekOrigin.Current"
+            );
+
+            Debug.Assert(
+                origin != SeekOrigin.Current || _resize || _position + offset <= _buffer.Length,
+                "Attempting to seek to a position beyond the capacity using SeekOrigin.Current without resize"
+            );
+
+            var newPosition = Math.Max(0, origin switch
             {
-                throw new OutOfMemoryException();
+                SeekOrigin.Current => _position + offset,
+                SeekOrigin.End     => Length + offset,
+                _                  => offset // Begin
+            });
+
+            if (newPosition >= _buffer.Length)
+            {
+                Grow(newPosition - _buffer.Length + 1);
             }
 
-            _buffer.Slice(Position, amount).Clear();
+            return _position = newPosition;
-            Position += amount;
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public int Seek(int offset, SeekOrigin origin) =>
+        public void Dispose()
-            Position = origin switch
+        {
+            byte[] toReturn = _arrayToReturnToPool;
+            this = default; // for safety, to avoid using pooled array if this instance is erroneously appended to again
+            if (toReturn != null)
             {
-                SeekOrigin.Begin => offset,
+                ArrayPool<byte>.Shared.Return(toReturn);
-                SeekOrigin.End   => Length - offset,
+            }
-                _                => Position + offset // Current
+        }
-            };
     }
 }

Projects/UOContent.Tests/UOContent.Tests.csproj

@@ -3,7 +3,7 @@
         <IsPackable>false</IsPackable>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.0-preview-20201123-03" />
         <PackageReference Include="xunit" Version="2.4.1" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
         <PackageReference Include="coverlet.collector" Version="1.3.0" />

Projects/UOContent/Gumps/Guilds/New Guild System/WarDeclarationGump.cs

@@ -45,7 +45,7 @@ namespace Server.Guilds
                 return;
             }
 
-            var playerRank = pm.GuildRank;
+            var playerRank = pm!.GuildRank;
 
             switch (info.ButtonID)
             {

Projects/UOContent/Gumps/Props/SetPoint2DGump.cs

@@ -69,7 +69,7 @@ namespace Server.Gumps
             m_Page = page;
             m_List = list;
 
-            var p = (Point2D)prop.GetValue(o, null);
+            var p = (Point2D)(prop?.GetValue(o, null) ?? new Point2D());
 
             AddPage(0);
 
@@ -86,7 +86,7 @@ namespace Server.Gumps
             var y = BorderSize + OffsetSize;
 
             AddImageTiled(x, y, EntryWidth, EntryHeight, EntryGumpID);
-            AddLabelCropped(x + TextOffsetX, y, EntryWidth - TextOffsetX, EntryHeight, TextHue, prop.Name);
+            AddLabelCropped(x + TextOffsetX, y, EntryWidth - TextOffsetX, EntryHeight, TextHue, prop?.Name);
             x += EntryWidth + OffsetSize;
 
             if (SetGumpID != 0)

Projects/UOContent/Gumps/Props/SetPoint3DGump.cs

@@ -69,7 +69,7 @@ namespace Server.Gumps
             m_Page = page;
             m_List = list;
 
-            var p = (Point3D)prop.GetValue(o, null);
+            var p = (Point3D)(prop?.GetValue(o, null) ?? new Point3D());
 
             AddPage(0);
 
@@ -86,7 +86,7 @@ namespace Server.Gumps
             var y = BorderSize + OffsetSize;
 
             AddImageTiled(x, y, EntryWidth, EntryHeight, EntryGumpID);
-            AddLabelCropped(x + TextOffsetX, y, EntryWidth - TextOffsetX, EntryHeight, TextHue, prop.Name);
+            AddLabelCropped(x + TextOffsetX, y, EntryWidth - TextOffsetX, EntryHeight, TextHue, prop?.Name);
             x += EntryWidth + OffsetSize;
 
             if (SetGumpID != 0)

Projects/UOContent/Gumps/Props/SetTimeSpanGump.cs

@@ -68,7 +68,7 @@ namespace Server.Gumps
             m_Page = page;
             m_List = list;
 
-            var ts = (TimeSpan)prop.GetValue(o, null);
+            var ts = (TimeSpan)(prop?.GetValue(o, null) ?? new TimeSpan());
 
             AddPage(0);
 
@@ -81,7 +81,7 @@ namespace Server.Gumps
                 OffsetGumpID
             );
 
-            AddRect(0, prop.Name, 0, -1);
+            AddRect(0, prop?.Name, 0, -1);
             AddRect(1, ts.ToString(), 0, -1);
             AddRect(2, "Zero", 1, -1);
             AddRect(3, "From H:M:S", 2, -1);

Projects/UOContent/Items/Skill Items/Specialized/GlassblowingBook.cs

@@ -29,24 +29,22 @@ namespace Server.Items
 
         public override void OnDoubleClick(Mobile from)
         {
-            var pm = from as PlayerMobile;
-
             if (!IsChildOf(from.Backpack))
             {
                 from.SendLocalizedMessage(1042001); // That must be in your pack for you to use it.
             }
-            else if (pm == null || from.Skills.Alchemy.Base < 100.0)
+            else if (from is not PlayerMobile pm || from.Skills.Alchemy.Base < 100.0)
             {
-                pm.SendMessage("Only a Grandmaster Alchemist can learn from this book.");
+                from.SendMessage("Only a Grandmaster Alchemist can learn from this book.");
             }
             else if (pm.Glassblowing)
             {
-                pm.SendMessage("You have already learned this information.");
+                from.SendMessage("You have already learned this information.");
             }
             else
             {
                 pm.Glassblowing = true;
-                pm.SendMessage(
+                from.SendMessage(
                     "You have learned to make items from glass. You will need to find miners to mine find sand for you to make these items."
                 );
                 Delete();

Projects/UOContent/Items/Skill Items/Specialized/MasonryBook.cs

@@ -29,24 +29,22 @@ namespace Server.Items
 
         public override void OnDoubleClick(Mobile from)
         {
-            var pm = from as PlayerMobile;
-
             if (!IsChildOf(from.Backpack))
             {
                 from.SendLocalizedMessage(1042001); // That must be in your pack for you to use it.
             }
-            else if (pm == null || from.Skills.Carpentry.Base < 100.0)
+            else if (from is not PlayerMobile pm || from.Skills.Carpentry.Base < 100.0)
             {
-                pm.SendMessage("Only a Grandmaster Carpenter can learn from this book.");
+                from.SendMessage("Only a Grandmaster Carpenter can learn from this book.");
             }
             else if (pm.Masonry)
             {
-                pm.SendMessage("You have already learned this information.");
+                from.SendMessage("You have already learned this information.");
             }
             else
             {
                 pm.Masonry = true;
-                pm.SendMessage(
+                from.SendMessage(
                     "You have learned to make items from stone. You will need miners to gather stones for you to make these items."
                 );
                 Delete();

Projects/UOContent/Items/Skill Items/Specialized/SandMiningBook.cs

@@ -29,24 +29,22 @@ namespace Server.Items
 
         public override void OnDoubleClick(Mobile from)
         {
-            var pm = from as PlayerMobile;
-
             if (!IsChildOf(from.Backpack))
             {
                 from.SendLocalizedMessage(1042001); // That must be in your pack for you to use it.
             }
-            else if (pm == null || from.Skills.Mining.Base < 100.0)
+            else if (from is not PlayerMobile pm || from.Skills.Mining.Base < 100.0)
             {
-                pm.SendMessage("Only a Grandmaster Miner can learn from this book.");
+                from.SendMessage("Only a Grandmaster Miner can learn from this book.");
             }
             else if (pm.SandMining)
             {
-                pm.SendMessage("You have already learned this information.");
+                from.SendMessage("You have already learned this information.");
             }
             else
             {
                 pm.SandMining = true;
-                pm.SendMessage(
+                from.SendMessage(
                     "You have learned how to mine fine sand. Target sand areas when mining to look for fine sand."
                 );
                 Delete();

Projects/UOContent/Items/Special/SoulStone.cs

@@ -156,10 +156,6 @@ namespace Server.Items
 
         protected virtual bool CheckUse(Mobile from)
         {
-            // DateTime now = DateTime.UtcNow;
-
-            var pm = from as PlayerMobile;
-
             if (Deleted || !IsAccessibleTo(from))
             {
                 return false;
@@ -235,11 +231,10 @@ namespace Server.Items
                 return false;
             }
 
-            if (pm.AcceleratedStart > DateTime.UtcNow)
+            if ((from as PlayerMobile)?.AcceleratedStart > DateTime.UtcNow)
             {
-                from.SendLocalizedMessage(
+                // You may not use a soulstone while your character is under the effects of a Scroll of Alacrity.
-                    1078115
+                from.SendLocalizedMessage(1078115);
-                ); // You may not use a soulstone while your character is under the effects of a Scroll of Alacrity.
                 return false;
             }
 
@@ -748,8 +743,7 @@ namespace Server.Items
                     return;
                 }
 
-                var pm = from as PlayerMobile;
+                if ((from as PlayerMobile)?.AcceleratedStart > DateTime.UtcNow)
-                if (pm.AcceleratedStart > DateTime.UtcNow)
                 {
                     // <CENTER>Unable to Absorb Selected Skill from Soulstone</CENTER>
 

Projects/UOContent/Mobiles/Monsters/ML/Humanoid/Magic/MLDryad.cs

@@ -103,14 +103,12 @@ namespace Server.Mobiles
 
             foreach (var m in GetMobilesInRange(RangePerception))
             {
-                var p = m as PlayerMobile;
+                if (m is PlayerMobile pm && IsValidTarget(pm))
-
-                if (IsValidTarget(p))
                 {
-                    p.PeacedUntil = DateTime.UtcNow + duration;
+                    pm.PeacedUntil = DateTime.UtcNow + duration;
-                    p.SendLocalizedMessage(1072065); // You gaze upon the dryad's beauty, and forget to continue battling!
+                    m.SendLocalizedMessage(1072065); // You gaze upon the dryad's beauty, and forget to continue battling!
-                    p.FixedParticles(0x376A, 1, 20, 0x7F5, EffectLayer.Waist);
+                    m.FixedParticles(0x376A, 1, 20, 0x7F5, EffectLayer.Waist);
-                    p.Combatant = null;
+                    m.Combatant = null;
                 }
             }
 

Projects/UOContent/UOContent.csproj

@@ -28,7 +28,7 @@
         <ProjectReference Include="..\Server\Server.csproj" Private="false" PrivateAssets="All" IncludeAssets="None">
             <IncludeInPackage>false</IncludeInPackage>
         </ProjectReference>
-        <PackageReference Include="MailKit" Version="2.8.0" />
+        <PackageReference Include="MailKit" Version="2.10.0" />
         <PackageReference Include="Microsoft.Toolkit.HighPerformance" Version="7.0.0-preview4" />
         <PackageReference Include="Zlib.Bindings" Version="1.4.0" />
         <PackageReference Include="Argon2.Bindings" Version="1.8.0" />