plugin-ext-vscode: apply file handlers only for user plugins

This patch fixes an unexpected behavior where Theia would also pick up
and deploy .vsix files from the local-plugins directory into the
deployedPlugins directory, where they will be treated as user-installed
extensions on the next start of theia.

Instead, we now only apply the file handlers for .vsix files if they are
user extensions. For system plugins, we print a warning message indicating
that the plugin has to be unpacked manually.

Fixes #13222

Contributed on behalf of STMicroelectronics

Signed-off-by: Olaf Lessenich <olessenich@eclipsesource.com>

packages/plugin-ext/src/main/node/plugin-deployer-impl.ts

@@ -225,8 +225,20 @@ export class PluginDeployerImpl implements PluginDeployer {
     }
 
     protected async resolveAndHandle(id: string, type: PluginType, options?: PluginDeployOptions): Promise<PluginDeployerEntry[]> {
-        const entries = await this.resolvePlugin(id, type, options);
-        await this.applyFileHandlers(entries);
+        let entries = await this.resolvePlugin(id, type, options);
+        if (type === PluginType.User) {
+            await this.applyFileHandlers(entries);
+        } else {
+            const filteredEntries: PluginDeployerEntry[] = [];
+            for (const entry of entries) {
+                if (await entry.isFile()) {
+                    this.logger.warn(`Only user plugins will be handled by file handlers, please unpack the plugin '${entry.id()}' manually.`);
+                } else {
+                    filteredEntries.push(entry);
+                }
+            }
+            entries = filteredEntries;
+        }
         await this.applyDirectoryFileHandlers(entries);
         return entries;
     }