RCS1258 Enum flag already contained: reported if only one bit matches

[ovska]

To trigger RCS1258, it seems like only one bit needs to match between the flags. Below is a reproduction, Test1 shows the fix suggestion, Test2 is after, and some example input where they return different values before and after the fix.

using System;

public class Program
{
    public static void Main()
    {
        Console.WriteLine(C.Test1(FooBar.Bar));
        Console.WriteLine(C.Test2(FooBar.Bar));
    }

    [System.Flags]
    internal enum FooBar
    {
        None = 0,
        Shared = 1,
        Foo = Shared | 2,
        Bar = Shared | 4,
    }

    class C
    {
        // before fixer
        public static bool Test1(FooBar x)
        {
            return x == (FooBar.Foo | FooBar.Bar);
        }

        // after fixer
        public static bool Test2(FooBar x)
        {
            return x == (FooBar.Bar);
        }
    }
}