Merge branch 'pr/1249'

app/lib/app.ts

@@ -58,7 +58,7 @@ export class Application {
         if (!this.hasWindows()) {
             await this.newWindow()
         }
-        this.windows[0].send(event, ...args)
+        this.windows.filter(w => !w.isDestroyed())[0].send(event, ...args)
     }
 
     enableTray () {

app/lib/index.ts

@@ -39,7 +39,7 @@ const argv = parseArgs(process.argv, process.cwd())
 
 if (!app.requestSingleInstanceLock()) {
     app.quit()
-    process.exit(0)
+    app.exit(0)
 }
 
 if (argv.d) {

app/lib/window.ts

@@ -147,6 +147,10 @@ export class Window {
         this.window.webContents.send(event, ...args)
     }
 
+    isDestroyed() {
+        return !this.window || this.window.isDestroyed();
+    }
+
     private setupWindowManagement () {
         this.window.on('show', () => {
             this.visible.next(true)