CopyComponent by Script for Unity

ComponentUtil.cs

using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;

using UnityEngine;

namespace Utils
{

    // http://answers.unity3d.com/questions/458207/copy-a-component-at-runtime.html
    // http://stackoverflow.com/questions/10261824/how-can-i-get-all-constants-of-a-type-by-reflection
    public class ComponentUtil
    {

        public static T CopyComponent<T>(T original, GameObject destination) where T : Component
        {
            System.Type type = original.GetType();

            var dst = destination.GetComponent(type) as T;
            if (!dst) dst = destination.AddComponent(type) as T;

            var fields = GetAllFields(type);
            foreach (var field in fields)
            {
                if (field.IsStatic) continue;
                field.SetValue(dst, field.GetValue(original));
            }

            var props = type.GetProperties();
            foreach (var prop in props)
            {
                if (!prop.CanWrite || !prop.CanWrite || prop.Name == "name") continue;
                prop.SetValue(dst, prop.GetValue(original, null), null);
            }

            return dst as T;
        }

        public static IEnumerable<FieldInfo> GetAllFields(System.Type t)
        {
            if (t == null)
            {
                return Enumerable.Empty<FieldInfo>();
            }

            BindingFlags flags = BindingFlags.Public | BindingFlags.NonPublic |
                                 BindingFlags.Static | BindingFlags.Instance |
                                 BindingFlags.DeclaredOnly;
            return t.GetFields(flags).Concat(GetAllFields(t.BaseType));
        }

    }

}

The field copy part clobbers most internal components of Unity, e.g. when copying an AudioSource.

This doesn't immediately show because the code disallows for multiple components; if it allowed multiple components to be added, you will see the problem.

Repro: Remove line 21 and try to clone a component (eg AudioSource) 20 times. It will show up erratically in the Inspector, and if you change one of its serialized properties (e.g. AudioClip), it will change in the copies as well.

when copy MeshRenderer, original and destination material will instante; this changed original`s property.