Continue using entities even when attached to a turret, in 1.11 and below for backwards compatibility!

Fixes #140 where the MG42 objective in m1l1 would not trigger

code/fgame/player.cpp

@@ -3438,6 +3438,12 @@ void Player::DoUse(Event *ev)
 
     num = getUseableEntities(touch, MAX_GENTITIES, true);
 
+    if (g_protocol >= protocol_e::PROTOCOL_MOHTA_MIN) {
+        // Fixed in 2.0
+        //  Since 2.0, the loop stops when the player
+        //  uses a turret, this prevents the turret from being deleted
+        //  after being attached to the player
+        //
         for (i = 0; i < num; i++) {
             hit = &g_entities[touch[i]];
 
@@ -3445,7 +3451,7 @@ void Player::DoUse(Event *ev)
                 continue;
             }
 
-        Event *event = new Event(EV_Use);
+            Event* event = new Event(EV_Use);
             event->AddListener(this);
 
             hit->entity->ProcessEvent(event);
@@ -3454,6 +3460,24 @@ void Player::DoUse(Event *ev)
                 break;
             }
         }
+    } else {
+        //
+        // Backward compatibility
+        // It still allows 1.11 SP to work properly
+        // Such as in m1l1 when the player must man the mounted machine gun
+        for (i = 0; i < num; i++) {
+            hit = &g_entities[touch[i]];
+
+            if (!hit->inuse) {
+                continue;
+            }
+
+            Event* event = new Event(EV_Use);
+            event->AddListener(this);
+
+            hit->entity->ProcessEvent(event);
+        }
+    }
 
     if (i < num && m_pVehicle) {
         //