Fix load/save for custom items

Author: yuripourre

Source/cursor.cpp

@@ -461,7 +461,6 @@ void FreeCursor()
 {
 	pCursCels = std::nullopt;
 	pCursCels2 = std::nullopt;
-	FreeCustomCursorSprites();
 	ClearCursor();
 }
 

Source/loadsave.cpp

@@ -1085,7 +1085,14 @@ void LoadMatchingItems(LoadHelper &file, const Player &player, const int n, Item
 		const bool success = LoadItemData(file, heroItem);
 		if (!success) {
 			heroItem.clear();
-			unpackedItem = Item();
+			// Do not clear unpackedItem: if the hero pack recreated it, keep it.
+		}
+		// If heroitems has valid data but the hero pack could not recreate
+		// the item (e.g. a custom mod item not in the drop tables), use
+		// heroitems as the primary source.
+		if (unpackedItem.isEmpty() && !heroItem.isEmpty()) {
+			unpackedItem = heroItem;
+			continue;
 		}
 		if (unpackedItem.isEmpty() || heroItem.isEmpty())
 			continue;

Source/tables/itemdat.cpp

@@ -11,6 +11,7 @@
 
 #include <fmt/format.h>
 
+#include "cursor.h"
 #include "data/file.hpp"
 #include "data/iterators.hpp"
 #include "data/record_reader.hpp"
@@ -611,6 +612,8 @@ namespace {
 
 void LoadItemDat()
 {
+	FreeCustomCursorSprites();
+
 	const std::string_view filename = "txtdata\\items\\itemdat.tsv";
 	DataFile dataFile = DataFile::loadOrDie(filename);