Fixed loading Lua modules of a plugin during its validation

app/MindWork AI Studio/Tools/PluginSystem/PluginFactory.Loading.cs

@@ -385,7 +385,15 @@ public static partial class PluginFactory
         }
     }
 
-    public static async Task<PluginBase> Load(string? pluginPath, string code, CancellationToken cancellationToken = default)
+    /// <param name="pluginPath">The directory the plugin is located in, or null when the code has no directory yet.</param>
+    /// <param name="code">The Lua code of the plugin's main file.</param>
+    /// <param name="cancellationToken">Cancellation token for running the Lua code.</param>
+    /// <param name="allowedBaseDirectory">
+    /// The directory the plugin path must be nested in. Without it, the installed plugins directory
+    /// is used. Validating a plugin before its installation needs this, because the plugin lives in
+    /// a staging directory at that point and could not load any of its own Lua modules otherwise.
+    /// </param>
+    public static async Task<PluginBase> Load(string? pluginPath, string code, CancellationToken cancellationToken = default, string? allowedBaseDirectory = null)
     {
         if(ForbiddenPlugins.Check(code) is { IsForbidden: true } forbiddenState)
             return new NoPlugin($"This plugin is forbidden: {forbiddenState.Message}");
@@ -394,7 +402,7 @@ public static partial class PluginFactory
         if (!string.IsNullOrWhiteSpace(pluginPath))
         {
             // Add the module loader so that the plugin can load other Lua modules:
-            state.ModuleLoader = new PluginLoader(pluginPath);
+            state.ModuleLoader = new PluginLoader(pluginPath, allowedBaseDirectory);
         }
 
         // Add some useful libraries:

app/MindWork AI Studio/Tools/PluginSystem/PluginLoader.cs

@@ -14,10 +14,17 @@ namespace AIStudio.Tools.PluginSystem;
 /// Loading other modules outside the plugin directory is not allowed.
 /// </remarks>
 /// <param name="pluginDirectory">The directory where the plugin is located.</param>
-public sealed class PluginLoader(string pluginDirectory) : ILuaModuleLoader
+/// <param name="allowedBaseDirectory">
+/// The directory the plugin directory must be nested in. Without it, the installed plugins directory
+/// is used. Validating a plugin before its installation needs this, because the plugin is not
+/// installed yet and lives in a staging directory outside the installed plugins directory.
+/// </param>
+public sealed class PluginLoader(string pluginDirectory, string? allowedBaseDirectory = null) : ILuaModuleLoader
 {
     private static readonly string PLUGIN_BASE_PATH = Path.Join(SettingsManager.DataDirectory, "plugins");
 
+    private readonly string baseDirectory = string.IsNullOrWhiteSpace(allowedBaseDirectory) ? PLUGIN_BASE_PATH : allowedBaseDirectory;
+
     #region Implementation of ILuaModuleLoader
 
     /// <inheritdoc />
@@ -27,8 +34,8 @@ public sealed class PluginLoader(string pluginDirectory) : ILuaModuleLoader
         if (moduleName.Contains("..") || pluginDirectory.Contains(".."))
             return false;
 
-        // Ensure that the plugin directory is nested in the plugin base path:
+        // Ensure that the plugin directory is nested in the allowed base directory:
-        if (!pluginDirectory.StartsWith(PLUGIN_BASE_PATH, StringComparison.OrdinalIgnoreCase))
+        if (!pluginDirectory.StartsWith(this.baseDirectory, StringComparison.OrdinalIgnoreCase))
             return false;
 
         var path = Path.Join(pluginDirectory, $"{moduleName}.lua");

app/MindWork AI Studio/Tools/Services/AssistantPluginInstallService.cs

@@ -572,7 +572,10 @@ public sealed class AssistantPluginInstallService
     private static async Task<AssistantPluginValidationResult> ValidateAssistantPluginCodeAsync(string pluginDirectory, string pluginCode,
         string notAssistantIssue, string invalidAssistantIssue, string internalPluginIdIssue, CancellationToken token)
     {
-        var plugin = await PluginFactory.Load(pluginDirectory, pluginCode, token);
+        // The plugin is not installed yet: it sits in a staging directory outside the installed
+        // plugins directory. We allow that directory as the module base, so the plugin can load its
+        // own Lua modules, e.g., an icon.lua, while we validate it:
+        var plugin = await PluginFactory.Load(pluginDirectory, pluginCode, token, pluginDirectory);
         if (plugin is not PluginAssistants assistantPlugin)
             return AssistantPluginValidationResult.Failure(string.Format(notAssistantIssue, string.Join("; ", plugin.Issues)));