Fix panic with dragging into the same loadout slot

common/src/comp/inventory/slot.rs

@@ -1,5 +1,6 @@
 use crate::{comp, comp::item};
 use comp::{Inventory, Loadout};
+use log::warn;
 
 #[derive(Clone, Copy, PartialEq, Debug, Serialize, Deserialize)]
 pub enum Slot {
@@ -169,6 +170,13 @@ fn swap_inventory_loadout(
 }
 
 fn swap_loadout(slot_a: EquipSlot, slot_b: EquipSlot, loadout: &mut Loadout) {
+    // Ensure that the slots are not the same (somehow the voxygen does this
+    // occasionsally)
+    if slot_a == slot_b {
+        warn!("Tried to swap equip slot with itself");
+        return;
+    }
+
     // Get items from the slots
     let item_a = loadout_remove(slot_a, loadout);
     let item_b = loadout_remove(slot_b, loadout);

voxygen/src/ui/widgets/ghost_image.rs

@@ -8,7 +8,7 @@ use conrod_core::{
 };
 
 /// This widget is like conrod's `Image` widget except it always returns false
-/// for is_over
+/// for is_over so widgets under it are still interactable
 #[derive(WidgetCommon)]
 pub struct GhostImage {
     #[conrod(common_builder)]

voxygen/src/ui/widgets/slot.rs

@@ -166,7 +166,11 @@ where
                         self.events.push(Event::Dropped(*slot));
                     } else if let Some(idx) = slot_ids.iter().position(|slot_id| *slot_id == id) {
                         // If widget is a slot widget swap with it
-                        self.events.push(Event::Dragged(*slot, slots[idx]));
+                        let (from, to) = (*slot, slots[idx]);
+                        // Don't drag if it is the same slot
+                        if from != to {
+                            self.events.push(Event::Dragged(from, to));
+                        }
                     }
                 }
                 // Mouse released stop dragging