Warn about in-place downgrades

Bloxstrap/App.xaml.cs

@@ -220,8 +220,10 @@ protected override void OnStartup(StartupEventArgs e)
 
  Locale.Set(Settings.Prop.Locale);
 
+#if !DEBUG
  if (!LaunchSettings.UninstallFlag.Active)
  Installer.HandleUpgrade();
+#endif
 
  LaunchHandler.ProcessLaunchArgs();
  }

Bloxstrap/Installer.cs

@@ -340,6 +340,18 @@ public static void HandleUpgrade()
  if (MD5Hash.FromFile(Paths.Process) == MD5Hash.FromFile(Paths.Application))
  return;
 
+ if (currentVer is not null && existingVer is not null && Utilities.CompareVersions(currentVer, existingVer) == VersionComparison.LessThan)
+ {
+ var result = Frontend.ShowMessageBox(
+ Strings.InstallChecker_VersionLessThanInstalled,
+ MessageBoxImage.Question,
+ MessageBoxButton.YesNo
+ );
+
+ if (result != MessageBoxResult.Yes)
+ return;
+ }
+
  // silently upgrade version if the command line flag is set or if we're launching from an auto update
  if (!App.LaunchSettings.UpgradeFlag.Active && !isAutoUpgrade)
  {
@@ -466,6 +478,9 @@ public static void HandleUpgrade()
  App.FastFlags.Save();
  }
 
+ if (currentVer is null)
+ return;
+
  if (isAutoUpgrade)
  {
  Utilities.ShellExecute($"https://github.com/{App.ProjectRepository}/wiki/Release-notes-for-Bloxstrap-v{currentVer}");

Bloxstrap/Resources/Strings.resx

@@ -1142,4 +1142,9 @@ If not, then please report this exception to the maintainers of this fork. Do NO
  <data name="Menu.UnsavedChanges" xml:space="preserve">
  <value>You have unsaved changes. Are you sure you want to close without saving?</value>
  </data>
+ <data name="InstallChecker.VersionLessThanInstalled" xml:space="preserve">
+ <value>The version of Bloxstrap you've launched is older than the version you currently have installed.
+Issues may occur and your settings may be altered. A reinstall is recommended.
+Are you sure you want to continue?</value>
+ </data>
 </root>