[5.4] Fix SessionGuard.php recaller method when request is null

[briandotdev]

recaller() method throws a non-object exception when $request is null. Null appears to be allowed behavior for $request as the constructor default is null. recaller() method is called by the user() method on line 140 the response is then checked for null on line 142. I believe in current form the recaller() method will never return null if $request is null.

[taylorotwell]

How did you create this error in a fresh application?

[GrahamCampbell]

Assignments inside boolean expressions should be avoided, since it leads to confusion and bugs.

[taylorotwell]

Cleaned it up a bit.

[briandotdev]

@taylorotwell use of the Auth Facade, specifically Auth::user() in a blade template which is accessible to both authenticated users and guest. My user model has a group attribute. When evaluating content for conditional display based on the user group @if(Auth::user()->group == 1), if the user is guest then I believe the request will be null.

This is probably better handled by me with a user check in the controller but as long as the Facade is accessible in the blade template I believe this scenario would be technically possible.

For quick reproduction, in a fresh install with a user created and logged out a call to Auth::user() in welcome.blade.php:

@if(Auth::user()->id == 1) <h1>Hello World</h1> @endif