From 4a1cf5f4736b6ff8d7de46fc6076b2e976ec287f Mon Sep 17 00:00:00 2001
From: maliming <malimings@gmail.com>
Date: Sun, 22 Feb 2026 19:36:37 +0800
Subject: [PATCH 1/2] Reject non-generic collections and add tests

Resolve #24914
---
 .../Abp/ObjectMapping/ObjectMappingHelper.cs  |  7 ++
 .../ObjectMappingHelper_Tests.cs              | 84 +++++++++++++++++++
 2 files changed, 91 insertions(+)
 create mode 100644 framework/test/Volo.Abp.ObjectMapping.Tests/Volo/Abp/ObjectMapping/ObjectMappingHelper_Tests.cs

diff --git a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
index 5949edaba9..f73b65b306 100644
--- a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
+++ b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
@@ -59,6 +59,13 @@ public static class ObjectMappingHelper
             supportedCollectionTypes.Contains(type.GetGenericTypeDefinition()) ||
             type.GetInterfaces().Any(i => i.IsGenericType && supportedCollectionTypes.Contains(i.GetGenericTypeDefinition())))
         {
+            if (!type.IsGenericType)
+            {
+                elementType = null!;
+                definitionGenericType = null!;
+                return false;
+            }
+
             elementType = type.GetGenericArguments()[0];
             definitionGenericType = type.GetGenericTypeDefinition();
             if (definitionGenericType == typeof(IEnumerable<>) ||
diff --git a/framework/test/Volo.Abp.ObjectMapping.Tests/Volo/Abp/ObjectMapping/ObjectMappingHelper_Tests.cs b/framework/test/Volo.Abp.ObjectMapping.Tests/Volo/Abp/ObjectMapping/ObjectMappingHelper_Tests.cs
new file mode 100644
index 0000000000..c262dad81a
--- /dev/null
+++ b/framework/test/Volo.Abp.ObjectMapping.Tests/Volo/Abp/ObjectMapping/ObjectMappingHelper_Tests.cs
@@ -0,0 +1,84 @@
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using Shouldly;
+using Xunit;
+
+namespace Volo.Abp.ObjectMapping;
+
+public class ObjectMappingHelper_Tests
+{
+    [Fact]
+    public void IsCollectionGenericType_Should_Return_True_For_Standard_GenericCollection()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<List<MappingTestSource>, List<MappingTestDestination>>(
+            out var sourceArg, out var destArg, out var defGenericType);
+
+        result.ShouldBeTrue();
+        sourceArg.ShouldBe(typeof(MappingTestSource));
+        destArg.ShouldBe(typeof(MappingTestDestination));
+        defGenericType.ShouldBe(typeof(List<>));
+    }
+
+    [Fact]
+    public void IsCollectionGenericType_Should_Return_True_For_Array()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<MappingTestSource[], MappingTestDestination[]>(
+            out var sourceArg, out var destArg, out _);
+
+        result.ShouldBeTrue();
+        sourceArg.ShouldBe(typeof(MappingTestSource));
+        destArg.ShouldBe(typeof(MappingTestDestination));
+    }
+
+    [Fact]
+    public void IsCollectionGenericType_Should_Normalize_IEnumerable_To_List()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<IEnumerable<MappingTestSource>, IEnumerable<MappingTestDestination>>(
+            out _, out _, out var defGenericType);
+
+        result.ShouldBeTrue();
+        defGenericType.ShouldBe(typeof(List<>));
+    }
+
+    [Fact]
+    public void IsCollectionGenericType_Should_Normalize_ICollection_To_Collection()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<ICollection<MappingTestSource>, ICollection<MappingTestDestination>>(
+            out _, out _, out var defGenericType);
+
+        result.ShouldBeTrue();
+        defGenericType.ShouldBe(typeof(Collection<>));
+    }
+
+    [Fact]
+    public void IsCollectionGenericType_Should_Return_False_For_NonCollection()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<MappingTestSource, MappingTestDestination>(
+            out _, out _, out _);
+
+        result.ShouldBeFalse();
+    }
+
+    [Fact]
+    public void IsCollectionGenericType_Should_Return_False_For_NonGeneric_DerivedCollection()
+    {
+        var result = ObjectMappingHelper.IsCollectionGenericType<List<MappingTestSource>, MappingTestDestinationList>(
+            out _, out _, out _);
+
+        result.ShouldBeFalse();
+    }
+}
+
+public class MappingTestSource
+{
+    public string Value { get; set; } = "";
+}
+
+public class MappingTestDestination
+{
+    public string Value { get; set; } = "";
+}
+
+public class MappingTestDestinationList : List<MappingTestDestination>
+{
+}

From ee47706de64bf1bf9acc5ab48ed99942b6de1638 Mon Sep 17 00:00:00 2001
From: maliming <malimings@gmail.com>
Date: Sun, 22 Feb 2026 19:47:53 +0800
Subject: [PATCH 2/2] Refactor condition in IsCollectionGenericTypeInternal for
 clarity

---
 .../Volo/Abp/ObjectMapping/ObjectMappingHelper.cs             | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
index f73b65b306..3bc1a1389b 100644
--- a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
+++ b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/ObjectMappingHelper.cs
@@ -55,8 +55,8 @@ public static class ObjectMappingHelper
             return true;
         }
 
-        if (type.IsGenericType &&
-            supportedCollectionTypes.Contains(type.GetGenericTypeDefinition()) ||
+        if ((type.IsGenericType &&
+             supportedCollectionTypes.Contains(type.GetGenericTypeDefinition())) ||
             type.GetInterfaces().Any(i => i.IsGenericType && supportedCollectionTypes.Contains(i.GetGenericTypeDefinition())))
         {
             if (!type.IsGenericType)