Try to use the remote port number locally (microsoft/vscode-remote-release#1115)

src/vs/workbench/services/remote/node/tunnelService.ts

@@ -16,6 +16,7 @@ import { nodeSocketFactory } from 'vs/platform/remote/node/nodeSocketFactory';
 import { ISignService } from 'vs/platform/sign/common/sign';
 import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { ILogService } from 'vs/platform/log/common/log';
+import { findFreePort } from 'vs/base/node/ports';
 
 export async function createRemoteTunnel(options: IConnectionOptions, tunnelRemotePort: number): Promise<RemoteTunnel> {
 	const tunnel = new NodeRemoteTunnel(options, tunnelRemotePort);
@@ -25,7 +26,7 @@ export async function createRemoteTunnel(options: IConnectionOptions, tunnelRemo
 class NodeRemoteTunnel extends Disposable implements RemoteTunnel {
 
 	public readonly tunnelRemotePort: number;
-	public readonly tunnelLocalPort: number;
+	public tunnelLocalPort: number;
 
 	private readonly _options: IConnectionOptions;
 	private readonly _server: net.Server;
@@ -47,7 +48,7 @@ class NodeRemoteTunnel extends Disposable implements RemoteTunnel {
 		this._server.on('connection', this._connectionListener);
 
 		this.tunnelRemotePort = tunnelRemotePort;
-		this.tunnelLocalPort = (<net.AddressInfo>this._server.listen(0).address()).port;
+
 	}
 
 	public dispose(): void {
@@ -58,6 +59,13 @@ class NodeRemoteTunnel extends Disposable implements RemoteTunnel {
 	}
 
 	public async waitForReady(): Promise<this> {
+
+		// try to get the same port number as the remote port number...
+		const localPort = await findFreePort(this.tunnelRemotePort, 1, 1000);
+
+		// if that fails, the method above returns 0, which works out fine below...
+		this.tunnelLocalPort = (<net.AddressInfo>this._server.listen(localPort).address()).port;
+
 		await this._barrier.wait();
 		return this;
 	}