Make sure we don't go into a redirect loop when using port mappings with same...

Make sure we don't go into a redirect loop when using port mappings with same source and destination ports

src/vs/workbench/contrib/webview/common/portMapping.ts

@@ -34,6 +34,9 @@ export class WebviewPortMappingManager extends Disposable {
 				if (extensionLocation && extensionLocation.scheme === REMOTE_HOST_SCHEME) {
 					const tunnel = await this.getOrCreateTunnel(mapping.extensionHostPort);
 					if (tunnel) {
+						if (tunnel.tunnelLocalPort === mapping.webviewPort) {
+							return undefined;
+						}
 						return encodeURI(uri.with({
 							authority: `127.0.0.1:${tunnel.tunnelLocalPort}`,
 						}).toString(true));