Fix color converter

Author: JimBobSquarePants

src/ImageSharp.Web/Commands/Converters/ArrayConverter{T}.cs

@@ -44,7 +44,10 @@ public T[] ConvertFrom(
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static string[] GetStringArray(string input, CultureInfo culture)
     {
-        char separator = culture.TextInfo.ListSeparator[0];
+        char separator = ConverterUtility.GetListSeparator(culture);
+
+        // TODO: Can we use StringSplit Enumerator here?
+        // https://github.com/dotnet/runtime/issues/934
         return input.Split(separator).Select(s => s.Trim()).ToArray();
     }
 }

src/ImageSharp.Web/Commands/Converters/ColorConverter.cs

@@ -17,7 +17,7 @@ public sealed class ColorConverter : ICommandConverter<Color>
     /// The web color hexadecimal regex. Matches strings arranged
     /// in rgb, rgba, rrggbb, or rrggbbaa format to match web syntax.
     /// </summary>
-    private static readonly Regex HexColorRegex = new("([0-9a-fA-F]{3}){1,2}", RegexOptions.Compiled);
+    private static readonly Regex HexColorRegex = new("([0-9a-fA-F][^,;.-]\\B{3}){1,2}", RegexOptions.Compiled);
 
     /// <summary>
     /// The number color regex.
@@ -41,12 +41,6 @@ public Color ConvertFrom(CommandParser parser, CultureInfo culture, string? valu
             return default;
         }
 
-        // Hex colors rgb, rrggbb, rrggbbaa
-        if (HexColorRegex.IsMatch(value))
-        {
-            return Color.ParseHex(value);
-        }
-
         // Named colors
         IDictionary<string, Color> table = ColorConstantsTable.Value;
         if (table.TryGetValue(value, out Color color))
@@ -55,7 +49,7 @@ public Color ConvertFrom(CommandParser parser, CultureInfo culture, string? valu
         }
 
         // Numeric r,g,b - r,g,b,a
-        char separator = culture.TextInfo.ListSeparator[0];
+        char separator = ConverterUtility.GetListSeparator(culture);
         if (value.IndexOf(separator) != -1)
         {
             string[] components = value.Split(separator);
@@ -82,6 +76,12 @@ public Color ConvertFrom(CommandParser parser, CultureInfo culture, string? valu
             }
         }
 
+        // Hex colors rgb, rrggbb, rrggbbaa
+        if (HexColorRegex.IsMatch(value))
+        {
+            return Color.ParseHex(value);
+        }
+
         return default;
     }
 

src/ImageSharp.Web/Commands/Converters/ConverterUtility.cs

@@ -0,0 +1,19 @@
+// Copyright (c) Six Labors.
+// Licensed under the Six Labors Split License.
+
+using System.Globalization;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace SixLabors.ImageSharp.Web.Commands.Converters;
+internal static class ConverterUtility
+{
+    /// <summary>
+    /// Gets the <see cref="char"/> that is used by the given culture to separate items in a list.
+    /// </summary>
+    /// <param name="culture">The culture.</param>
+    /// <returns>The <see cref="char"/>.</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static char GetListSeparator(CultureInfo culture)
+        => MemoryMarshal.GetReference<char>(culture.TextInfo.ListSeparator);
+}

src/ImageSharp.Web/Commands/Converters/EnumConverter.cs

@@ -34,7 +34,7 @@ public sealed class EnumConverter : ICommandConverter<object>
 
         try
         {
-            char separator = culture.TextInfo.ListSeparator[0];
+            char separator = ConverterUtility.GetListSeparator(culture);
             if (value.IndexOf(separator) != -1)
             {
                 long convertedValue = 0;
@@ -63,5 +63,8 @@ public sealed class EnumConverter : ICommandConverter<object>
     /// <returns>The <see cref="T:String[]"/>.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static string[] GetStringArray(string input, char separator)
+
+        // TODO: Can we use StringSplit Enumerator here?
+        // https://github.com/dotnet/runtime/issues/934
         => input.Split(separator).Select(s => s.Trim()).ToArray();
 }

src/ImageSharp.Web/Commands/Converters/ListConverter{T}.cs

@@ -44,7 +44,10 @@ public List<T> ConvertFrom(
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private static string[] GetStringArray(string input, CultureInfo culture)
     {
-        char separator = culture.TextInfo.ListSeparator[0];
+        char separator = ConverterUtility.GetListSeparator(culture);
+
+        // TODO: Can we use StringSplit Enumerator here?
+        // https://github.com/dotnet/runtime/issues/934
         return input.Split(separator).Select(s => s.Trim()).ToArray();
     }
 }