From a3960b30c04d5313b0bfb3d57a7da35af5e8af3b Mon Sep 17 00:00:00 2001
From: Bond-009 <bond.009@outlook.com>
Date: Sun, 29 Mar 2026 14:28:41 -0400
Subject: [PATCH] Backport pull request #16369 from jellyfin/release-10.11.z

Fix nullref ex in font handling

Original-merge: 41c2d51d8cb9b4f9bdf81be6e73f7ae2d447a8d7

Merged-by: Bond-009 <bond.009@outlook.com>

Backported-by: Bond_009 <bond.009@outlook.com>
---
 src/Jellyfin.Drawing.Skia/SkiaEncoder.cs | 57 +++++++++++++++---------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/src/Jellyfin.Drawing.Skia/SkiaEncoder.cs b/src/Jellyfin.Drawing.Skia/SkiaEncoder.cs
index c6eab92ead..ade993d927 100644
--- a/src/Jellyfin.Drawing.Skia/SkiaEncoder.cs
+++ b/src/Jellyfin.Drawing.Skia/SkiaEncoder.cs
@@ -25,7 +25,7 @@ public class SkiaEncoder : IImageEncoder
     private readonly ILogger<SkiaEncoder> _logger;
     private readonly IApplicationPaths _appPaths;
     private static readonly SKImageFilter _imageFilter;
-    private static readonly SKTypeface[] _typefaces;
+    private static readonly SKTypeface?[] _typefaces = InitializeTypefaces();
 
     /// <summary>
     /// The default sampling options, equivalent to old high quality filter settings when upscaling.
@@ -37,9 +37,7 @@ public class SkiaEncoder : IImageEncoder
     /// </summary>
     public static readonly SKSamplingOptions DefaultSamplingOptions;
 
-#pragma warning disable CA1810
     static SkiaEncoder()
-#pragma warning restore CA1810
     {
         var kernel = new[]
         {
@@ -59,21 +57,6 @@ public class SkiaEncoder : IImageEncoder
             SKShaderTileMode.Clamp,
             true);
 
-        // Initialize the list of typefaces
-        // We have to statically build a list of typefaces because MatchCharacter only accepts a single character or code point
-        // But in reality a human-readable character (grapheme cluster) could be multiple code points. For example, 🚵🏻‍♀️ is a single emoji but 5 code points (U+1F6B5 + U+1F3FB + U+200D + U+2640 + U+FE0F)
-        _typefaces =
-        [
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, '鸡'), // CJK Simplified Chinese
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, '雞'), // CJK Traditional Chinese
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, 'ノ'), // CJK Japanese
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, '각'), // CJK Korean
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, 128169), // Emojis, 128169 is the 💩emoji
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, 'ז'), // Hebrew
-            SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, 'ي'), // Arabic
-            SKTypeface.FromFamilyName("sans-serif", SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright) // Default font
-        ];
-
         // use cubic for upscaling
         UpscaleSamplingOptions = new SKSamplingOptions(SKCubicResampler.Mitchell);
         // use bilinear for everything else
@@ -132,7 +115,7 @@ public class SkiaEncoder : IImageEncoder
     /// <summary>
     /// Gets the default typeface to use.
     /// </summary>
-    public static SKTypeface DefaultTypeFace => _typefaces.Last();
+    public static SKTypeface? DefaultTypeFace => _typefaces.Last();
 
     /// <summary>
     /// Check if the native lib is available.
@@ -152,6 +135,40 @@ public class SkiaEncoder : IImageEncoder
         }
     }
 
+    /// <summary>
+    /// Initialize the list of typefaces
+    /// We have to statically build a list of typefaces because MatchCharacter only accepts a single character or code point
+    /// But in reality a human-readable character (grapheme cluster) could be multiple code points. For example, 🚵🏻‍♀️ is a single emoji but 5 code points (U+1F6B5 + U+1F3FB + U+200D + U+2640 + U+FE0F)
+    /// </summary>
+    /// <returns>The list of typefaces.</returns>
+    private static SKTypeface?[] InitializeTypefaces()
+    {
+        int[] chars = [
+            '鸡', // CJK Simplified Chinese
+            '雞', // CJK Traditional Chinese
+            'ノ', // CJK Japanese
+            '각', // CJK Korean
+            128169, // Emojis, 128169 is the Pile of Poo (💩) emoji
+            'ז', // Hebrew
+            'ي' // Arabic
+        ];
+        var fonts = new List<SKTypeface>(chars.Length + 1);
+        foreach (var ch in chars)
+        {
+            var font = SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, ch);
+            if (font is not null)
+            {
+                fonts.Add(font);
+            }
+        }
+
+        // Default font
+        fonts.Add(SKTypeface.FromFamilyName("sans-serif", SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright)
+            ?? SKFontManager.Default.MatchCharacter(null, SKFontStyleWeight.Bold, SKFontStyleWidth.Normal, SKFontStyleSlant.Upright, null, 'a'));
+
+        return fonts.ToArray();
+    }
+
     /// <summary>
     /// Convert a <see cref="ImageFormat"/> to a <see cref="SKEncodedImageFormat"/>.
     /// </summary>
@@ -809,7 +826,7 @@ public class SkiaEncoder : IImageEncoder
     {
         foreach (var typeface in _typefaces)
         {
-            if (typeface.ContainsGlyphs(c))
+            if (typeface is not null && typeface.ContainsGlyphs(c))
             {
                 return typeface;
             }