SERVER_NAME still implicitly changes routing behavior

[BoWuGit]

Just like this old issue said, routing behavior changed even when subdomain_matching defaults to false, so take this repository as example, if you comment following lines,

@app.before_request
def start():
    """
    init globals and set the schema search path for the current request.
    """
    g.user = session.get('user', None)
    current_url = urlparse(request.url)
    subdomain = current_url.hostname.split('.')

    if subdomain.__len__() > 2:
        """
        redirect to home page
        """
        if current_url.path == "/":
            return redirect(url_for('index'))
        pass
    pass

then requests to user1.flask-subdomain.com won't route to index, default 404 as response. Or am I missing something, as a result have misunderstood it. Thanks very much.

@app.route('/')
def index():
    return render_template('index.html')

Environment

• Python version: 3.6
• Flask version: 1.1.1
• Werkzeug version: 0.16.0

[davidism]

I'm sorry, it looks like you're asking about code in another repository. As far as I can tell SERVER_NAME works as intended at this point.

[davidism]

#5634 in Flask 3.1 will further address this. SERVER_NAME no longer affects routing except to determine subdomains if subdomain_matching is enabled.