Fix regression to allow custom value conversion mapping when the ClrT…

…ype is of non-NTS type. plus added unit test.

 - regression introduced in commit [3ef628f](3ef628f#diff-4f1d25d8c94e4764d1beef032d7ecc17efaf6a2f592db3dab748bac1d7fc0446R87)

Refs #1921

Dependencies.targets

@@ -46,6 +46,7 @@
     <PackageReference Update="DotNetAnalyzers.DocumentationAnalyzers" Version="1.0.0-beta.59" />
     <PackageReference Update="StyleCop.Analyzers" Version="1.1.118" PrivateAssets="All" />
     <PackageReference Update="Microsoft.CodeAnalysis" Version="4.5.0" />
+    <PackageReference Update="Shouldly" Version="4.0.3" />
     <PackageReference Update="Microsoft.CodeAnalysis.Features" Version="4.5.0" />
     <PackageReference Update="Microsoft.CodeAnalysis.CSharp.Features" Version="4.5.0" />
     <PackageReference Update="Microsoft.CodeAnalysis.VisualBasic.Features" Version="4.5.0" />

src/EFCore.MySql.NTS/Storage/Internal/MySqlNetTopologySuiteTypeMappingSourcePlugin.cs

@@ -80,16 +80,30 @@ public virtual RelationalTypeMapping FindMapping(in RelationalTypeMappingInfo ma
             string defaultStoreType = null;
             Type defaultClrType = null;
 
-            return (clrType != null
-                    && TryGetDefaultStoreType(clrType, out defaultStoreType))
-                   || (storeTypeName != null
-                       && _spatialStoreTypeMappings.TryGetValue(storeTypeName, out defaultClrType))
-                ? (RelationalTypeMapping)Activator.CreateInstance(
+            var hasDefaultStoreType = clrType != null
+                    && TryGetDefaultStoreType(clrType, out defaultStoreType);
+            var hasDefaultClrType = storeTypeName != null
+                       && _spatialStoreTypeMappings.TryGetValue(storeTypeName, out defaultClrType);
+
+            if (!(hasDefaultStoreType || hasDefaultClrType))
+            {
+                return null;
+            }
+
+            // NOTE: If the incoming user-specified 'clrType' is of the known calculated 'defaultClrType', ONLY then proceeed
+            // with the creation of 'MySqlGeometryTypeMapping'.
+            clrType = clrType == null
+                ? defaultClrType
+                : clrType.IsAssignableFrom(defaultClrType)
+                    ? clrType
+                    : null;
+            return clrType == null
+                ? null
+                : (RelationalTypeMapping)Activator.CreateInstance(
                     typeof(MySqlGeometryTypeMapping<>).MakeGenericType(clrType ?? defaultClrType ?? typeof(Geometry)),
                     _geometryServices,
                     storeTypeName ?? defaultStoreType ?? "geometry",
-                    _options)
-                : null;
+                    _options);
         }
 
         private static bool TryGetDefaultStoreType(Type type, out string defaultStoreType)

test/EFCore.MySql.FunctionalTests/EFCore.MySql.FunctionalTests.csproj

@@ -32,6 +32,7 @@
     <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" />
     <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Json" />
+    <PackageReference Include="Shouldly" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(LocalEFCoreRepository)' == ''">

test/EFCore.MySql.FunctionalTests/NTS/CustomValueConvertersForNonNTSClrTypesMySqlTest.cs

@@ -0,0 +1,96 @@
+namespace Pomelo.EntityFrameworkCore.MySql.FunctionalTests.NTS;
+
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using NetTopologySuite.Geometries;
+using Pomelo.EntityFrameworkCore.MySql.Tests;
+using Shouldly;
+using Xunit;
+
+public class CustomValueConvertersForNonNTSClrTypesMySqlTest
+{
+    [Fact]
+    public async Task NonNTS_ClrType_CanBe_Mapped_to_CustomValueConverters()
+    {
+        var services = new ServiceCollection()
+            .AddDbContext<CustomDbContext>()
+            .AddSingleton(
+                new DbContextOptionsBuilder<CustomDbContext>()
+                    .UseMySql(
+                        AppConfig.ConnectionString,
+                        AppConfig.ServerVersion,
+                        options =>
+                        {
+                            options.UseNetTopologySuite();
+                        })
+                    .EnableSensitiveDataLogging()
+                    .LogTo(Console.WriteLine, LogLevel.Debug)
+                .Options);
+
+        var provider = services.BuildServiceProvider();
+        await using var context = provider.GetRequiredService<CustomDbContext>();
+
+        // Validate `MySqlNetTopologySuiteTypeMappingSourcePlugin.FindMapping()` doesn't throw.
+        await Should.NotThrowAsync(context.Database.EnsureDeletedAsync());
+        await Should.NotThrowAsync(context.Database.EnsureCreatedAsync());
+    }
+}
+
+public sealed class CustomDbContext(DbContextOptions<CustomDbContext> options) : DbContext(options)
+{
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        var testClass = modelBuilder.Entity<TestClass>();
+        testClass.Property(t => t.Vertices)
+            .HasColumnType("GEOMETRY")
+            .HasConversion(new MysqlGeometryWkbValueConverter());
+
+        var testClass2 = modelBuilder.Entity<TestClass2>();
+        testClass2.Property(t => t.Vertices)
+            .HasColumnType("GEOMETRY");
+    }
+}
+
+public class TestClass
+{
+    public int Id { get; set; }
+#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
+    public byte[] Vertices { get; set; }
+#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
+}
+
+public class TestClass2
+{
+    public int Id { get; set; }
+
+#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
+    public Geometry Vertices { get; set; }
+#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
+}
+
+/// <summary>
+///   MySql's internal geometry format is WKB with an initial 4
+///   bytes for the SRID:
+///   https://dev.mysql.com/doc/refman/5.7/en/gis-data-formats.html
+/// </summary>
+public class MysqlGeometryWkbValueConverter : ValueConverter<byte[], byte[]>
+{
+    public MysqlGeometryWkbValueConverter()
+        : base(
+              clr => AddSRID(clr),
+              col => StripSRID(col))
+    {
+    }
+
+    private static byte[] AddSRID(byte[] wkb) =>
+        new byte[] { 0, 0, 0, 0, }.Concat(wkb).ToArray();
+
+    private static byte[] StripSRID(byte[] col) =>
+        col.Skip(4).ToArray();
+}