Cannot upload file when $grav['user'] is not set

[AndruePeters]

Cannot upload file if $grav['user'] is not set.
Issue is on Grav 1.6.9 and 1.6.10. These are the only two versions I tested.

Fix is to change code in https://github.com/getgrav/grav-plugin-form/blob/develop/classes/Form.php on line 641 to

// We need to store the file into flash object or it will not be available upon save later on.
  $flash = $this->getFlash();
  if (isset($grav['user'])) {
    $flash->setUrl($url)->setUser($grav['user']);
  } else {
    $flash->setUrl($url);
  }

This also works:

$flash->setUrl($url)->setUser($grav['user'] ?? null);

This is with the fix:

This is without the fix:

I am not familiar with handling sessions with grav, but a comment in #332 says a session is needed. This works with system.session.enabled = false.
Also, is this maybe the issue for #349 ?

[rhukster]

Looks like a decent fix.. @mahagr was working on some form updates recently related to flash storage, so be good for him to take a look.

[mahagr]

Looks like I missed that one. Fixed now. I also found some other similar issues, will add checks against them, too.