[nullable check]'from clause' should have nullable check in query expression

[bysdxt]

Version Used:
.NET SDK 7.0.202
Visual Studio 17.5.2

Code:

#nullable enable
using System;
using System.Linq;
using System.Collections.Generic;
namespace ConsoleApp1 {
    internal class Program {
        static IEnumerable<int> f(IEnumerable<int>? x) {
            return from v in x select v + 1;
        }
        static IEnumerable<int> h(IEnumerable<int>? x) {
            foreach (var v in x)
                yield return v + 1;
        }
        static IEnumerable<int> g(IEnumerable<int>? x) {
            return x.Select(v => v + 1);
        }
        static void Main() {
            Console.WriteLine("Hello, World!");
        }
    }
}

sharplab

Expected Behavior:
All three functions f/h/g are warned about nullable problem
Actual Behavior:
Only function h/g are warned. No warning in function f.

[jcouv]

This is a known issue. We don't track nullability within LINQ queries. Closing as duplicate of #29863