fix: harden engine across casino, economy, concurrency, security, and content

1 files changed, 20 insertions, 3 deletions

diff --git a/internal/game/production_index.go b/internal/game/production_index.go
index ffacd8a..35466a7 100644
--- a/internal/game/production_index.go
+++ b/internal/game/production_index.go
@@ -272,6 +272,19 @@ func consumeIngredients(c *item.CraftDef, countItem func(string) int, removeItem
 	return true
 }
 
+// stackProps returns the Quality and MaxQuality a NEW inventory stack of def
+// receives, mirroring newInventorySlot (core_utils.go): a quality-bearing
+// definition is stamped at its full quality. Every stack-creation and
+// stack-merge site must agree on these values, or a stack produced by one
+// path (craft, harvest, ammo removal, shop) stops merging with the same item
+// picked up from the ground while the inventory is full.
+func stackProps(def *item.ItemDef) (quality, maxQuality int) {
+	if def != nil && def.MaxQuality > 0 {
+		return def.MaxQuality, def.MaxQuality
+	}
+	return 0, 0
+}
+
 // craftOutputFits reports whether outputQty of an item can be placed into
 // the inventory right now: merged into an existing stack for stackable
 // definitions, otherwise a free slot. Crafters must check BEFORE consuming
@@ -279,8 +292,10 @@ func consumeIngredients(c *item.CraftDef, countItem func(string) int, removeItem
 // producing the output.
 func craftOutputFits(p *player.Player, itemID string, outDef *item.ItemDef) bool {
 	if outDef != nil && outDef.Stackable {
+		quality, maxQuality := stackProps(outDef)
 		for i := 0; i < 28; i++ {
-			if slot := p.InvSlot(i); slot != nil && slot.ItemID == itemID {
+			slot := p.InvSlot(i)
+			if slot != nil && slot.ItemID == itemID && slot.Quality == quality && slot.MaxQuality == maxQuality {
 				return true
 			}
 		}
@@ -294,9 +309,11 @@ func craftOutputFits(p *player.Player, itemID string, outDef *item.ItemDef) bool
 // (consumption cannot free fewer slots than the check saw on the owner
 // goroutine, so a false return is defensive).
 func placeCraftOutput(p *player.Player, itemID string, outDef *item.ItemDef, outputQty int) bool {
+	quality, maxQuality := stackProps(outDef)
 	if outDef != nil && outDef.Stackable {
 		for i := 0; i < 28; i++ {
-			if slot := p.InvSlot(i); slot != nil && slot.ItemID == itemID {
+			slot := p.InvSlot(i)
+			if slot != nil && slot.ItemID == itemID && slot.Quality == quality && slot.MaxQuality == maxQuality {
 				slot.Quantity += outputQty
 				return true
 			}
@@ -306,6 +323,6 @@ func placeCraftOutput(p *player.Player, itemID string, outDef *item.ItemDef, out
 	if freeSlot == -1 {
 		return false
 	}
-	p.SetInvSlot(freeSlot, &player.InventorySlot{ItemID: itemID, Quantity: outputQty})
+	p.SetInvSlot(freeSlot, &player.InventorySlot{ItemID: itemID, Quantity: outputQty, Quality: quality, MaxQuality: maxQuality})
 	return true
 }