"Add To Home Screen" creates a bookmark with a broken "startapp&addToHomeScreen" parameter

[alexeyhimself]

Checklist

• [+] I am reporting an issue in existing functionality that does not work as intended
• [+] I've searched for existing GitHub issues

Description

While creating a bookmark for a Mini App using "Add To Home Screen", Mini App offers to save a bookmark in a https://t.me/botname_bot?startapp&addToHomeScreen broken format (& between startapp key and addToHomeScreen value) instead of valid and working format: https://t.me/botname_bot?startapp=addToHomeScreen. This leads to not passing addToHomeScreen parameter in start_params into Mini App: window.Telegram.WebApp.initDataUnsafe.start_param is undefined, as well as it is not passed in GET parameters.

Expected Behavior

Mini App on "Add to Home Screen" offers to create a bookmark for https://t.me/botname_bot?startapp=addToHomeScreen URL and addToHomeScreen parameter exists both in GET URL and in window.Telegram.WebApp.initDataUnsafe.start_param.

Actual Behavior

Mini App on "Add to Home Screen" offers to create a bookmark for https://t.me/botname_bot?startapp&addToHomeScreen URL and addToHomeScreen is missing both in GET URL and in window.Telegram.WebApp.initDataUnsafe.start_param.

Steps to Reproduce

1. Open Mini App
2. Click on 3 dots top-right corner menu
3. Select "Add to Home Screen" menu option
4. Check URL of the bookmark that is about to be created

Screenshots and Videos

Environment

Device: iPhone 7
iOS version: 15.8.5
App version: 12.3.2

See Also

Looks like the same on Android. Should I submit a separate bug for Android as well?

[laktyushin]

This is not a bug. The behavior is intentional.
The addToHomeScreen parameter is not supposed to be passed to the Mini App.

[alexeyhimself]

@laktyushin, why do we pass addToHomeScreen as an URL parameter at all then? What is it for?

My point is:

1. How do we know that the app was opened from the home screen icon then?
2. More than that, the parameter is already there, in the URL, but it is not passed as a startapp parameter into the app.

I needed this functionality (to know that the mini-app was opened from the icon), that's why I did the research on why addToHomeScreen is in the URL, but is not available in the app, found this broken function, and submitted a bug.