(hopefully) Fix updater crash if Configs folder doesn't exist in old …

…version once and for all

This also fixes potential issues with the Updater trying to access System32 folders (due to the way that Windows resolves relative paths)

Fixes #64

YAMDCC.Updater/GitHubApi/ApiError.cs

@@ -21,7 +21,7 @@ namespace YAMDCC.Updater.GitHubApi;
 // suppress warning about default values never getting overwritten
 // since they get populated when deserialising JSON to these classes
 #pragma warning disable CS0649
-internal class ApiError
+internal sealed class ApiError
 {
     [JsonProperty("message")]
     public string Message;

YAMDCC.Updater/GitHubApi/Author.cs

@@ -21,7 +21,7 @@ namespace YAMDCC.Updater.GitHubApi;
 // suppress warning about default values never getting overwritten
 // since they get populated when deserialising JSON to these classes
 #pragma warning disable CS0649
-internal class Author
+internal sealed class Author
 {
     [JsonProperty("login")]
     public string Login;

YAMDCC.Updater/GitHubApi/Release.cs

@@ -22,7 +22,7 @@ namespace YAMDCC.Updater.GitHubApi;
 // suppress warning about default values never getting overwritten
 // since they get populated when deserialising JSON to these classes
 #pragma warning disable CS0649
-internal class Release
+internal sealed class Release
 {
     [JsonProperty("url")]
     public string Url;

YAMDCC.Updater/GitHubApi/ReleaseAsset.cs

@@ -22,7 +22,7 @@ namespace YAMDCC.Updater.GitHubApi;
 // suppress warning about default values never getting overwritten
 // since they get populated when deserialising JSON to these classes
 #pragma warning disable CS0649
-internal class ReleaseAsset
+internal sealed class ReleaseAsset
 {
     [JsonProperty("url")]
     public string Url;

YAMDCC.Updater/Program.cs

@@ -154,6 +154,7 @@ private static void InstallUpdate(
                 {
                     // copy new configs individually since we can't
                     // merge directories without extra work
+                    Directory.CreateDirectory(confPath);
                     foreach (FileInfo fi in dir.GetFiles())
                     {
                         fi.MoveTo(Path.Combine(confPath, fi.Name));

YAMDCC.Updater/UpdateForm.cs

@@ -46,10 +46,10 @@ internal sealed partial class UpdateForm : Form
 
     private static readonly string ExeName = Path.GetFileName(Assembly.GetEntryAssembly().Location);
     private static readonly string TargetPath = Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);
-    private static readonly string DownloadPath = Path.GetFullPath("YAMDCC-Update.zip");
-    private static readonly string UpdatePath = Path.GetFullPath("Update");
-    private static readonly string OldPath = Path.GetFullPath("Old");
-    private static readonly string ConfPath = Path.GetFullPath("Configs");
+    private static readonly string DownloadPath = Path.GetFullPath(@".\YAMDCC-Update.zip");
+    private static readonly string UpdatePath = Path.GetFullPath(@".\Update");
+    private static readonly string OldPath = Path.GetFullPath(@".\Old");
+    private static readonly string ConfPath = Path.GetFullPath(@".\Configs");
 
     public UpdateForm(Release release = null, bool autoUpdate = false)
     {