NullReferenceException in TextMeasurer.MeasureBounds

[woutware]

A NullReferenceException is thrown in method SixLabors.Fonts.Tables.AdvancedTypographic.Shapers.UniversalShaper.SetupSyllables().

Tested in version SixLabors.Fonts 2.0.2, ImageSharp 3.1.3. ImageSharp.Drawing.2.1.2, ran in .NET 6.0.

Code to reproduce:

using System;

using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Drawing.Processing;
using SixLabors.Fonts;

namespace ConsoleApp {
    public static class SixLaborsBug {

        public static void MeasureTextBug() {
            string s = " 꿹ꓴ/ꥀ냘";
            FontCollection fonts = new FontCollection();
            FontFamily fontFamily = fonts.Add(@"C:\Windows\Fonts\arial.ttf");
            Font font = new Font(fontFamily, 10f);
            var bounds = TextMeasurer.MeasureBounds(s, new TextOptions(font));
            Console.WriteLine($"{bounds.Width}, {bounds.Height}");
        }
    }
}

Call stack:

>	SixLabors.Fonts.dll!SixLabors.Fonts.Tables.AdvancedTypographic.Shapers.UniversalShaper.SetupSyllables(SixLabors.Fonts.IGlyphShapingCollection collection, int index, int count) Line 155	C#
 	SixLabors.Fonts.dll!SixLabors.Fonts.Tables.AdvancedTypographic.GSubTable.ApplySubstitution(SixLabors.Fonts.FontMetrics fontMetrics, SixLabors.Fonts.GlyphSubstitutionCollection collection) Line 160	C#
 	SixLabors.Fonts.dll!SixLabors.Fonts.StreamFontMetrics.ApplySubstitution(SixLabors.Fonts.GlyphSubstitutionCollection collection) Line 272	C#
 	SixLabors.Fonts.dll!SixLabors.Fonts.TextLayout.DoFontRun(System.ReadOnlySpan<char> text, int start, System.Collections.Generic.IReadOnlyList<SixLabors.Fonts.TextRun> textRuns, ref int textRunIndex, ref int codePointIndex, ref int bidiRunIndex, bool isFallbackRun, SixLabors.Fonts.Font font, SixLabors.Fonts.Unicode.BidiRun[] bidiRuns, System.Collections.Generic.Dictionary<int, int> bidiMap, SixLabors.Fonts.GlyphSubstitutionCollection substitutions, SixLabors.Fonts.GlyphPositioningCollection positionings) Line 811	C#
 	SixLabors.Fonts.dll!SixLabors.Fonts.TextLayout.ProcessText(System.ReadOnlySpan<char> text, SixLabors.Fonts.TextOptions options) Line 138	C#
 	SixLabors.Fonts.dll!SixLabors.Fonts.TextMeasurer.MeasureBounds(string text, SixLabors.Fonts.TextOptions options) Line 56	C#
 	ConsoleApp.dll!ConsoleApp.SixLaborsBug.MeasureTextBug() Line 18	C#

[mes51]

Maybe same Issue.
#388

The caller is different, but the error appears to be coming from the same code.
It appears that a combination of several script classes can cause a NullReferenceException.

[JimBobSquarePants]

You're correct. Same issue.