Allow externalTerminal.windowExec to work with spaces

Fixes #6590

src/vs/workbench/parts/execution/electron-browser/terminalService.ts

@@ -32,7 +32,9 @@ export class WinTerminalService implements ITerminalService {
 	private spawnTerminal(spawner, configuration: ITerminalConfiguration, command: string, path?: string): TPromise<void> {
 		let terminalConfig = configuration.externalTerminal;
 		let exec = terminalConfig.windowsExec || DEFAULT_TERMINAL_WINDOWS;
-		let cmdArgs = ['/c', 'start', '/wait', exec];
+		// The '""' argument is the window title. Without this, exec doesn't work when the path
+		// contains spaces
+		let cmdArgs = ['/c', 'start', '/wait', '""', exec];
 
 		return new TPromise<void>((c, e) => {
 			let env = path ? { cwd: path } : void 0;