Fix an item duplication glitch

apps/openmw/mwgui/container.cpp

@@ -88,8 +88,13 @@ namespace MWGui
 
         mDragAndDropWidget->setVisible(false);
 
-        targetModel->copyItem(mItem, mDraggedCount);
-        mSourceModel->removeItem(mItem, mDraggedCount);
+        // If item is dropped where it was taken from, we don't need to do anything -
+        // otherwise, do the transfer
+        if (targetModel != mSourceModel)
+        {
+            targetModel->copyItem(mItem, mDraggedCount);
+            mSourceModel->removeItem(mItem, mDraggedCount);
+        }
 
         mSourceModel->update();
 

apps/openmw/mwgui/containeritemmodel.cpp

@@ -74,13 +74,12 @@ ItemModel::ModelIndex ContainerItemModel::getIndex (ItemStack item)
 void ContainerItemModel::copyItem (const ItemStack& item, size_t count)
 {
     const MWWorld::Ptr& source = mItemSources[mItemSources.size()-1];
+    if (item.mBase.getContainerStore() == &source.getClass().getContainerStore(source))
+        throw std::runtime_error("Item to copy needs to be from a different container!");
     int origCount = item.mBase.getRefData().getCount();
     item.mBase.getRefData().setCount(count);
-    MWWorld::ContainerStoreIterator it = MWWorld::Class::get(source).getContainerStore(source).add(item.mBase, source);
-    if (*it != item.mBase)
-        item.mBase.getRefData().setCount(origCount);
-    else
-        item.mBase.getRefData().setCount(origCount + count); // item copied onto itself
+    source.getClass().getContainerStore(source).add(item.mBase, source);
+    item.mBase.getRefData().setCount(origCount);
 }
 
 void ContainerItemModel::removeItem (const ItemStack& item, size_t count)

apps/openmw/mwgui/inventoryitemmodel.cpp

@@ -40,13 +40,12 @@ ItemModel::ModelIndex InventoryItemModel::getIndex (ItemStack item)
 
 void InventoryItemModel::copyItem (const ItemStack& item, size_t count)
 {
+    if (item.mBase.getContainerStore() == &mActor.getClass().getContainerStore(mActor))
+        throw std::runtime_error("Item to copy needs to be from a different container!");
     int origCount = item.mBase.getRefData().getCount();
     item.mBase.getRefData().setCount(count);
-    MWWorld::ContainerStoreIterator it = MWWorld::Class::get(mActor).getContainerStore(mActor).add(item.mBase, mActor);
-    if (*it != item.mBase)
-        item.mBase.getRefData().setCount(origCount);
-    else
-        item.mBase.getRefData().setCount(origCount + count); // item copied onto itself
+    mActor.getClass().getContainerStore(mActor).add(item.mBase, mActor);
+    item.mBase.getRefData().setCount(origCount);
 }