`RichTextOptions.TextRuns` Should initialize with `Array.Empty<RichTextRuns>()`

[yt6983138]

Prerequisites

• I have written a descriptive issue title
• I have verified if the problem exist in both DEBUG and RELEASE mode
• I have verified that I am running the latest version of ImageSharp
• I have searched open and closed issues to ensure it has not already been reported

ImageSharp version

3.1.4

Other ImageSharp packages and versions

SixLabors.Drawing 2.1.3, SixLabors.Fonts 2.0.3

Environment (Operating system, version and so on)

Windows 10 pro 22H2, 48g ddr4, i7 13700, gtx 650 ti boost

.NET Framework version

.NET 8.0.2

Description

By default, a new instance of RichTextOptions do not initialize property TextRuns with IReadOnlyList (though base TextOptions initialize it with Array.Empty()), so if any code tries to access TextRuns property of a just newly created instance of RichTextOptions, it throws an InvalidCastException

Steps to Reproduce

FontFamily fontFamily = SystemFonts.Collection.Families.First();
Font font = fontFamily.CreateFont(69); // just an example font, as font is required to construct a richTextOptions

TextOptions textOptions = new(font);
Console.WriteLine(string.Join(',', textOptions.TextRuns)); // ok

RichTextOptions richTextOptions = new(font);
try
{
	Console.WriteLine(string.Join(',', richTextOptions.TextRuns)); // fault
}
catch (Exception ex)
{
	Console.WriteLine(ex);
	//System.InvalidCastException: Unable to cast object of type 'SixLabors.Fonts.TextRun[]' to type 'System.Collections.Generic.IReadOnlyList`1[SixLabors.ImageSharp.Drawing.Processing.RichTextRun]'.
	//   at SixLabors.ImageSharp.Drawing.Processing.RichTextOptions.get_TextRuns()
}
richTextOptions.TextRuns = Array.Empty<RichTextRun>(); // ok
Console.WriteLine(string.Join(',', richTextOptions.TextRuns)); // ok

Images

No response

[Autoquark]

Not sure if this is still being watched (will open a new issue if not) but I believe the introduction of the RichTextOptions constructor that takes an existing RichTextOptions has caused this issue to appear again, as that constructor does not initialize RichTextOptions.TextRuns to an empty array of RichTextRun like the other constructor does.

[JimBobSquarePants]

Not sure if this is still being watched (will open a new issue if not) but I believe the introduction of the RichTextOptions constructor that takes an existing RichTextOptions has caused this issue to appear again, as that constructor does not initialize RichTextOptions.TextRuns to an empty array of RichTextRun like the other constructor does.

You're correct. When we clone a run, we do not copy its text runs properly. I've just fixed that for the latest major locally and will look at backporting it if possible. Thanks!