send quit to engine upon our own quit

src/95_hub.js

@@ -2251,6 +2251,11 @@ let hub_props = {
 	// ---------------------------------------------------------------------------------------------------------------------
 	// Misc...
 
+	quit: function() {
+		this.engine.shutdown();
+		ipcRenderer.send("terminate");
+	},
+
 	set_special_message: function(s, css_class, duration) {
 		this.status_handler.set_special_message(s, css_class, duration);
 		this.draw_statusbox();

src/main.js

@@ -90,6 +90,15 @@ function startup() {
 		alert(messages.renderer_hang);
 	});
 
+	win.once("close", (event) => {					// Note the once...
+		event.preventDefault();						// We prevent the close one time only,
+		win.webContents.send("call", "quit");		// to let renderer's "quit" method run once. It then sends "terminate" back.
+	});
+
+	electron.ipcMain.on("terminate", () => {
+		win.close();
+	});
+
 	electron.app.on("window-all-closed", () => {
 		electron.app.quit();
 	});