Changed UserName to non-deterministic field

.devcontainer/pgsql/docker-compose.yaml

@@ -25,7 +25,7 @@ services:
     image: postgres:17.2
     restart: unless-stopped
     volumes:
-      - postgres-data:/var/lib/postgresql/data
+      - ./pgdata/var/lib/postgresql/data
     environment:
       POSTGRES_PASSWORD: jellyfin
       POSTGRES_USER: jellyfin
@@ -47,5 +47,4 @@ services:
     # (Adding the "ports" property to this file will not forward from a Codespace.)
 
 volumes:
-  postgres-data:
   pgadmin-data:

Jellyfin.Api/Controllers/UserController.cs

@@ -390,7 +390,7 @@ public class UserController : BaseJellyfinApiController
             return StatusCode(StatusCodes.Status403Forbidden, "User update not allowed.");
         }
 
-        if (!string.Equals(user.Username, updateUser.Name, StringComparison.Ordinal))
+        if (!string.Equals(user.Username, updateUser.Name, StringComparison.OrdinalIgnoreCase))
         {
             await _userManager.RenameUser(user, updateUser.Name).ConfigureAwait(false);
         }

Jellyfin.Database/Jellyfin.Database.Implementations/ModelConfiguration/UserConfiguration.cs

@@ -13,8 +13,7 @@ namespace Jellyfin.Server.Implementations.ModelConfiguration
         public void Configure(EntityTypeBuilder<User> builder)
         {
             builder
-                .Property(user => user.Username)
-                .UseCollation("NOCASE");
+                .Property(user => user.Username);
 
             builder
                 .HasOne(u => u.ProfileImage)

Jellyfin.Database/Jellyfin.Database.Providers.PgSql/Migrations/20250127174201_InitMigration.cs

@@ -12,9 +12,6 @@ namespace Jellyfin.Database.Providers.PgSql.Migrations
         /// <inheritdoc />
         protected override void Up(MigrationBuilder migrationBuilder)
         {
-            // shim NOCASE collation with an undefined locale and case-insensitive matching rules.
-            migrationBuilder.Sql("CREATE COLLATION NOCASE (provider = icu, locale = 'und-x-icu.utf8', deterministic = false)");
-
             migrationBuilder.CreateTable(
                 name: "ActivityLogs",
                 columns: table => new
@@ -230,7 +227,7 @@ namespace Jellyfin.Database.Providers.PgSql.Migrations
                 columns: table => new
                 {
                     Id = table.Column<Guid>(type: "uuid", nullable: false),
-                    Username = table.Column<string>(type: "character varying(255)", maxLength: 255, nullable: false, collation: "NOCASE"),
+                    Username = table.Column<string>(type: "character varying(255)", maxLength: 255, nullable: false),
                     Password = table.Column<string>(type: "character varying(65535)", maxLength: 65535, nullable: true),
                     MustUpdatePassword = table.Column<bool>(type: "boolean", nullable: false),
                     AudioLanguagePreference = table.Column<string>(type: "character varying(255)", maxLength: 255, nullable: true),

Jellyfin.Server.Implementations/Users/UserManager.cs

@@ -147,7 +147,7 @@ namespace Jellyfin.Server.Implementations.Users
 
             ThrowIfInvalidUsername(newName);
 
-            if (user.Username.Equals(newName, StringComparison.Ordinal))
+            if (user.Username.Equals(newName, StringComparison.OrdinalIgnoreCase))
             {
                 throw new ArgumentException("The new and old names must be different.");
             }
@@ -155,8 +155,11 @@ namespace Jellyfin.Server.Implementations.Users
             var dbContext = await _dbProvider.CreateDbContextAsync().ConfigureAwait(false);
             await using (dbContext.ConfigureAwait(false))
             {
+#pragma warning disable CA1862 // Use the 'StringComparison' method overloads to perform case-insensitive string comparisons
+#pragma warning disable CA1311 // Specify a culture or use an invariant version to avoid implicit dependency on current culture
+#pragma warning disable CA1304 // The behavior of 'string.ToUpper()' could vary based on the current user's locale settings
                 if (await dbContext.Users
-                        .AnyAsync(u => u.Username == newName && !u.Id.Equals(user.Id))
+                        .AnyAsync(u => u.Username.ToUpper() == newName.ToUpper() && !u.Id.Equals(user.Id))
                         .ConfigureAwait(false))
                 {
                     throw new ArgumentException(string.Format(
@@ -164,6 +167,9 @@ namespace Jellyfin.Server.Implementations.Users
                         "A user with the name '{0}' already exists.",
                         newName));
                 }
+#pragma warning restore CA1304 // The behavior of 'string.ToUpper()' could vary based on the current user's locale settings
+#pragma warning restore CA1311 // Specify a culture or use an invariant version to avoid implicit dependency on current culture
+#pragma warning restore CA1862 // Use the 'StringComparison' method overloads to perform case-insensitive string comparisons
 
                 user.Username = newName;
                 await UpdateUserInternalAsync(dbContext, user).ConfigureAwait(false);