Restore pty host connection correctly after restart

Part of microsoft#185254

Author: Tyriar

src/vs/workbench/contrib/terminal/browser/baseTerminalBackend.ts

@@ -42,6 +42,7 @@ export abstract class BaseTerminalBackend extends Disposable {
 
 		let unresponsiveStatusBarEntry: IStatusbarEntry;
 		let statusBarAccessor: IStatusbarEntryAccessor;
+		let hasStarted = false;
 
 		// Attach pty host listeners
 		if (this._ptyHostController.onPtyHostExit) {
@@ -51,7 +52,12 @@ export abstract class BaseTerminalBackend extends Disposable {
 		}
 		if (this._ptyHostController.onPtyHostStart) {
 			this._register(this._ptyHostController.onPtyHostStart(() => {
-				this._onPtyHostRestart.fire();
+				this._logService.debug(`The terminal's pty host process is starting`);
+				// Only fire the event on the 2nd
+				if (hasStarted) {
+					this._onPtyHostRestart.fire();
+				}
+				hasStarted = true;
 				statusBarAccessor?.dispose();
 				this._isPtyHostUnresponsive = false;
 			}));

src/vs/workbench/contrib/terminal/electron-sandbox/localTerminalBackend.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { Emitter } from 'vs/base/common/event';
+import { Emitter, Event } from 'vs/base/common/event';
 import { IProcessEnvironment, isMacintosh, isWindows, OperatingSystem } from 'vs/base/common/platform';
 import { withNullAsUndefined } from 'vs/base/common/types';
 import { URI } from 'vs/base/common/uri';
@@ -52,8 +52,7 @@ export class LocalTerminalBackendContribution implements IWorkbenchContribution
 class LocalTerminalBackend extends BaseTerminalBackend implements ITerminalBackend {
 	readonly remoteAuthority = undefined;
 
-	private readonly _proxy: IPtyService;
-	private readonly _clientEventually: DeferredPromise<MessagePortClient> = new DeferredPromise();
+	private _proxy!: IPtyService;
 	private readonly _ptys: Map<number, LocalPty> = new Map();
 
 	private readonly _whenConnected = new DeferredPromise<void>();
@@ -84,12 +83,15 @@ class LocalTerminalBackend extends BaseTerminalBackend implements ITerminalBacke
 	) {
 		super(_localPtyService, logService, historyService, _configurationResolverService, statusBarService, workspaceContextService);
 
-		this._proxy = ProxyChannel.toService<IPtyService>(getDelayedChannel(this._clientEventually.p.then(client => client.getChannel(TerminalIpcChannels.PtyHostWindow))));
-
-		this._connectToDirectProxy();
+		this._register(Event.runAndSubscribe(this.onPtyHostRestart, () => {
+			this._logService.debug('Starting pty host');
+			const clientEventually = new DeferredPromise<MessagePortClient>();
+			this._proxy = ProxyChannel.toService<IPtyService>(getDelayedChannel(clientEventually.p.then(client => client.getChannel(TerminalIpcChannels.PtyHostWindow))));
+			this._connectToDirectProxy(clientEventually);
+		}));
 	}
 
-	private async _connectToDirectProxy(): Promise<void> {
+	private async _connectToDirectProxy(clientEventually: DeferredPromise<MessagePortClient>): Promise<void> {
 		// The pty host should not get launched until the first window restored phase
 		await this._lifecycleService.when(LifecyclePhase.Restored);
 
@@ -103,7 +105,7 @@ class LocalTerminalBackend extends BaseTerminalBackend implements ITerminalBacke
 			// used for pty host management messages, it would make sense in the future to use a
 			// separate interface/service for this one.
 			const client = new MessagePortClient(port, `window:${this._environmentService.window.id}`);
-			this._clientEventually.complete(client);
+			clientEventually.complete(client);
 
 			// Attach process listeners
 			this._proxy.onProcessData(e => this._ptys.get(e.id)?.handleData(e.event));