Fix efficiency and unbreaking not working together

This commit fixes an issue were tools enchanted with both efficiency and
unbreaking would loose the effect of one of the enchantments in some
conditions.

mods/ITEMS/mcl_enchanting/enchantments.lua

@@ -771,11 +771,11 @@ mcl_enchanting.enchantments.unbreaking = {
 	curse = false,
 	on_enchant = function(itemstack, level)
 		local tool_capabilities = itemstack:get_tool_capabilities()
-		for group, capability in pairs(tool_capabilities.groupcaps) do
-			capability.uses = capability.uses * (1 + level)
-		end
 		tool_capabilities.punch_attack_uses = tool_capabilities.punch_attack_uses * (1 + level)
 		itemstack:get_meta():set_tool_capabilities(tool_capabilities)
+
+		-- Unbreaking for groupcaps is handled in this function.
+		mcl_enchanting.update_groupcaps(itemstack)
 	end,
 	requires_tool = true,
 	treasure = false,

mods/ITEMS/mcl_enchanting/engine.lua

@@ -17,6 +17,7 @@ function mcl_enchanting.unload_enchantments(itemstack)
 	local meta = itemstack:get_meta()
 	if meta:get_string("name") == "" then
 		meta:set_string("description", "")
+		meta:set_string("groupcaps_hash", "")
 	end
 end
 

mods/ITEMS/mcl_enchanting/groupcaps.lua

@@ -50,13 +50,21 @@ function mcl_enchanting.update_groupcaps(itemstack)
 	end
 
 	local name = itemstack:get_name()
-	local level = mcl_enchanting.get_enchantment(itemstack, "efficiency")
+	local efficiency = mcl_enchanting.get_enchantment(itemstack, "efficiency")
-	local groupcaps = get_efficiency_groupcaps(name, level)
+	local groupcaps = get_efficiency_groupcaps(name, efficiency)
 	local hash = itemstack:get_meta():get_string("groupcaps_hash")
 
 	if not hash or hash ~= groupcaps.hash then
 		local tool_capabilities = itemstack:get_tool_capabilities()
 		tool_capabilities.groupcaps = groupcaps.values
+
+		-- Increase the number of uses depending on the unbreaking level
+		-- of the tool.
+		local unbreaking = mcl_enchanting.get_enchantment(itemstack, "unbreaking")
+		for group, capability in pairs(tool_capabilities.groupcaps) do
+			capability.uses = capability.uses * (1 + unbreaking)
+		end
+
 		itemstack:get_meta():set_tool_capabilities(tool_capabilities)
 		itemstack:get_meta():set_string("groupcaps_hash", groupcaps.hash)
 	end