fix: cargo allocator crash when cargo flight but no airline

app/Allocator/Stand/CargoFlightPreferredArrivalStandAllocator.php

@@ -29,11 +29,16 @@ public function __construct(AirlineService $airlineService)
 
     public function allocate(NetworkAircraft $aircraft): ?int
     {
-        // If the aircraft doesnt have an airline, we cant allocate a stand
+        // If the aircraft isn't a cargo airline or a cargo flight, this rule doesn't apply
         if (!$this->isCargoAirline($aircraft) && !$this->isCargoFlight($aircraft)) {
             return null;
         }
 
+        // If the aircarft has no airline at all, there's nothing we can do
+        if ($aircraft->airline_id === null) {
+            return null;
+        }
+
         return $this->selectAirlineSpecificStands(
             $aircraft,
             $this->queryFilter()

tests/app/Allocator/Stand/CargoFlightPreferredArrivalStandAllocatorTest.php

@@ -131,6 +131,14 @@ public function testItDoesntAllocateCargoStandsIfNoAirline()
         $this->assertNull($allocation);
     }
 
+    public function testItDoesntAllocateCargoStandsIfNoAirlineButIsCargoFlight()
+    {
+        $aircraft = $this->createAircraft('ABCDEF', 'EGLL');
+        $aircraft->remarks = 'Some stuff RMK/CARGO Some more stuff';
+        $allocation = $this->allocator->allocate($aircraft);
+        $this->assertNull($allocation);
+    }
+
     public function testItDoesntRankStandsIfUnknownAircraft()
     {
         $aircraft = $this->newAircraft('BAW1234', 'EGLL', 'C172');