V10: AllowedUploadFiles appsetting not working

src/Umbraco.Core/Configuration/ContentSettingsExtensions.cs

@@ -10,9 +10,9 @@ public static class ContentSettingsExtensions
     ///     Allow upload if extension is whitelisted OR if there is no whitelist and extension is NOT blacklisted.
     /// </summary>
     public static bool IsFileAllowedForUpload(this ContentSettings contentSettings, string extension) =>
-        contentSettings.AllowedUploadFiles.Any(x => x.InvariantEquals(extension)) ||
-        (contentSettings.AllowedUploadFiles.Any() == false &&
-         contentSettings.DisallowedUploadFiles.Any(x => x.InvariantEquals(extension)) == false);
+        contentSettings.AllowedUploadedFileExtensions.Any(x => x.InvariantEquals(extension)) ||
+        (contentSettings.AllowedUploadedFileExtensions.Any() == false &&
+         contentSettings.DisallowedUploadedFileExtensions.Any(x => x.InvariantEquals(extension)) == false);
 
     /// <summary>
     ///     Gets the auto-fill configuration for a specified property alias.

src/Umbraco.Core/Configuration/Models/ContentSettings.cs

@@ -196,11 +196,13 @@ @keyframes umbraco-preview-badge--effect {{
     ///     Gets or sets a value for the collection of file extensions that are disallowed for upload.
     /// </summary>
     [DefaultValue(StaticDisallowedUploadFiles)]
+    [Obsolete("Please use DisAllowedUploadedFileExtensions instead, scheduled for removal in V13")]
     public IEnumerable<string> DisallowedUploadFiles { get; set; } = StaticDisallowedUploadFiles.Split(',');
 
     /// <summary>
     ///     Gets or sets a value for the collection of file extensions that are allowed for upload.
     /// </summary>
+    [Obsolete("Please use AllowedUploadedFileExtensions instead, scheduled for removal in V13")]
     public IEnumerable<string> AllowedUploadFiles { get; set; } = Array.Empty<string>();
 
     /// <summary>
@@ -249,4 +251,15 @@ @keyframes umbraco-preview-badge--effect {{
     /// </summary>
     [DefaultValue(StaticAllowEditInvariantFromNonDefault)]
     public bool AllowEditInvariantFromNonDefault { get; set; } = StaticAllowEditInvariantFromNonDefault;
+
+    /// <summary>
+    ///     Gets or sets a value for the collection of file extensions that are allowed for upload.
+    /// </summary>
+    public string[] AllowedUploadedFileExtensions { get; set; } = Array.Empty<string>();
+
+    /// <summary>
+    ///     Gets or sets a value for the collection of file extensions that are disallowed for upload.
+    /// </summary>
+    [DefaultValue(StaticDisallowedUploadFiles)]
+    public string[] DisallowedUploadedFileExtensions { get; set; } = StaticDisallowedUploadFiles.Split(',');
 }

src/Umbraco.Core/DependencyInjection/UmbracoBuilder.Configuration.cs

@@ -119,6 +119,32 @@ public static IUmbracoBuilder AddConfiguration(this IUmbracoBuilder builder)
             }
         });
 
+        // TODO: Remove this in V13
+        // This is to avoid a breaking change in ContentSettings, if the old AllowedFileUploads has a value, and the new
+        // AllowedFileUploadExtensions does not, copy the value over, if the new has a value, use that instead.
+        builder.Services.Configure<ContentSettings>(settings =>
+        {
+            // We have to use Config.GetSection().Get<string[]>, as the GetSection.GetValue<string[]> simply cannot retrieve a string array
+            var allowedUploadedFileExtensionsValue = builder.Config.GetSection($"{Constants.Configuration.ConfigContent}:{nameof(ContentSettings.AllowedUploadedFileExtensions)}").Get<string[]>();
+            var allowedUploadFilesValue = builder.Config.GetSection($"{Constants.Configuration.ConfigContent}:{nameof(ContentSettings.AllowedUploadFiles)}").Get<string[]>();
+
+            if (allowedUploadedFileExtensionsValue is null && allowedUploadFilesValue is not null)
+            {
+                settings.AllowedUploadedFileExtensions = allowedUploadFilesValue;
+            }
+        });
+
+        // TODO: Remove this in V13
+        builder.Services.Configure<ContentSettings>(settings =>
+        {
+            var disallowedUploadedFileExtensionsValue = builder.Config.GetSection($"{Constants.Configuration.ConfigContent}:{nameof(ContentSettings.DisallowedUploadedFileExtensions)}").Get<string[]>();
+            var disallowedUploadFilesValue = builder.Config.GetSection($"{Constants.Configuration.ConfigContent}:{nameof(ContentSettings.DisallowedUploadFiles)}").Get<string[]>();
+
+            if (disallowedUploadedFileExtensionsValue is null && disallowedUploadFilesValue is not null)
+            {
+                settings.DisallowedUploadedFileExtensions = disallowedUploadFilesValue;
+            }
+        });
         return builder;
     }
 }

src/Umbraco.Web.BackOffice/Controllers/BackOfficeServerVariables.cs

@@ -543,11 +543,11 @@ internal async Task<Dictionary<string, object>> GetServerVariablesAsync()
                         },
                         {
                             "disallowedUploadFiles",
-                            string.Join(",", _contentSettings.DisallowedUploadFiles)
+                            string.Join(",", _contentSettings.DisallowedUploadedFileExtensions)
                         },
                         {
                             "allowedUploadFiles",
-                            string.Join(",", _contentSettings.AllowedUploadFiles)
+                            string.Join(",", _contentSettings.AllowedUploadedFileExtensions)
                         },
                         {
                             "maxFileSize",