ObjectMappingHelper detects derived List<T> as collection, but DefaultObjectMapper crashes with IndexOutOfRangeException

[fangqifan]

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Description

ObjectMappingHelper.IsCollectionGenericTypeInternal incorrectly handles non-generic types derived from generic collections (e.g., CarDtoList : List).

When calling:

ObjectMapper.Map<List<Car>, CarDtoList>(cars)

the collection check passes, but later mapping fails with IndexOutOfRangeException because type.GetGenericArguments()[0] is accessed on a non-generic derived type.

This causes collection mapping to fail for valid custom collection types derived from List.

Reproduction Steps

1.Define DTO/entity types:

public class Car { public string Model { get; set; } = ""; }
public class CarDto { public string Model { get; set; } = ""; }
public class CarDtoList : List<CarDto> { }

2.Call:

var cars = new List<Car> { new Car { Model = "A" } };
var mapper= serviceProvider.GetService<IObjectMapper>();
var result = mapper.Map<List<Car>, CarDtoList>(cars);

Expected behavior

If this scenario is not intended to be supported (custom non-generic derived collection types like CarDtoList : List), the framework should safely return null from collection-type detection (so mapping falls back to other strategies) instead of throwing an exception (IndexOutOfRangeException).

Actual behavior

Throws IndexOutOfRangeException in collection type detection/mapping path (around ObjectMappingHelper.cs line ~62 in my local source).

Regression?

No response

Known Workarounds

No response

Version

10.1-rc3

User Interface

Common (Default)

Database Provider

EF Core (Default)

Tiered or separate authentication server

None (Default)

Operation System

Windows (Default)

Other information

No response