Fix custom item mod sections not hiding properly

spec/System/TestItemMods_spec.lua

@@ -859,6 +859,29 @@ describe("TetsItemMods", function()
 		assert.is_true(controls.displayItemCustomModifierRemove1:IsShown())
 	end)
 
+	it("hides custom modifier controls after saving the display item", function()
+		build.itemsTab:CreateDisplayItemFromRaw([[
+			Rarity: RARE
+			Test Item
+			Iron Ring
+			Implicits: 1
+			Adds 1 to 4 Physical Damage to Attacks
+			{crafted}+8 to Strength
+		]])
+
+		local controls = build.itemsTab.controls
+		assert.is_true(controls.displayItemCustomModifierRemove1:IsShown())
+		assert.is_true(controls.displayItemCustomModifier1:IsShown())
+
+		build.itemsTab:AddDisplayItem()
+
+		assert.is_nil(build.itemsTab.displayItem)
+		assert.is_falsy(controls.displayItemSectionCustom:IsShown())
+		assert.is_falsy(controls.displayItemCustomModifierRemove1:IsShown())
+		assert.is_falsy(controls.displayItemCustomModifier1:IsShown())
+		assert.is_falsy(controls.displayItemCustomModifierLabel1:IsShown())
+	end)
+
 	it("shows affix controls for items crafted in Path of Building", function()
 		build.itemsTab:CreateDisplayItemFromRaw([[
 			Rarity: RARE

src/Classes/ItemsTab.lua

@@ -985,6 +985,9 @@ holding Shift will put it in the second.]])
 	self.controls.displayItemSectionCustom = new("Control", {"TOPLEFT",self.controls.displayItemSectionAffix,"BOTTOMLEFT",true}, {0, 0, 0, function()
 		return (self.controls.displayItemAddCustom:IsShown() or self.controls.displayItemAddCrucible:IsShown()) and 28 + self.displayItem.customCount * 22 or 0
 	end})
+	self.controls.displayItemSectionCustom.shown = function()
+		return self.displayItem ~= nil
+	end
 	self.controls.displayItemAddCustom = new("ButtonControl", {"TOPLEFT",self.controls.displayItemSectionCustom,"TOPLEFT"}, {0, 0, 120, 20}, "Add modifier...", function()
 		self:AddCustomModifierToDisplayItem()
 	end)