Fix INVALID_REF errors caused by mods (#657)

`INVALID_REF` errors were being caused by trying to get the item image for weapon skins.

If a mod (e.g. moreskins) added new skins, the client equipped one, and then the mod is disabled, the client now has bad persistence.
This is mostly handled fine by the game, except for weapon skins. This PR prevents the crash, and resets the bad persistence to default.

Northstar.Client/mod/scripts/vscripts/ui/menu_edit_pilot_loadouts.nut

@@ -82,6 +82,11 @@ void function OnLoadoutButton_Focused( var button )
 {
 	int index = expect int( button.s.rowIndex )
 
+	// update the editingLoadoutIndex on focus so that it always matches
+	// with the pilot loadout panel
+	uiGlobal.editingLoadoutIndex = index
+	uiGlobal.editingLoadoutType = "pilot"
+
 	UpdatePilotLoadout( index )
 
 	string pilotLoadoutRef = "pilot_loadout_" + ( index + 1 )

Northstar.Client/mod/scripts/vscripts/ui/menu_pilot_loadouts_shared.nut

@@ -86,23 +86,23 @@ void function UpdatePilotLoadoutPanel( var loadoutPanel, PilotLoadoutDef loadout
 	else if ( loadout.primarySkinIndex == 1 ) // camo
 		primaryAppearanceImage = CamoSkin_GetImage( CamoSkins_GetByIndex( loadout.primaryCamoIndex ) )
 	else // warpaint skin
-		primaryAppearanceImage = GetItemImage( GetSkinRefFromWeaponRefAndPersistenceValue( loadout.primary, loadout.primarySkinIndex ) )
+		primaryAppearanceImage = GetItemImageFromWeaponRefAndPersistenceValue( loadout.primary, loadout.primarySkinIndex, "primarySkinIndex" )
 
 	asset secondaryAppearanceImage
 	if ( loadout.secondarySkinIndex == 0 ) // default skin
 		secondaryAppearanceImage = $"rui/menu/common/appearance_button_swatch"
 	else if ( loadout.secondarySkinIndex == 1 ) // camo
 		secondaryAppearanceImage = CamoSkin_GetImage( CamoSkins_GetByIndex( loadout.secondaryCamoIndex ) )
 	else // warpaint skin
-		secondaryAppearanceImage = GetItemImage( GetSkinRefFromWeaponRefAndPersistenceValue( loadout.secondary, loadout.secondarySkinIndex ) )
+		secondaryAppearanceImage = GetItemImageFromWeaponRefAndPersistenceValue( loadout.secondary, loadout.secondarySkinIndex, "secondarySkinIndex" )
 
 	asset weapon3AppearanceImage
 	if ( loadout.weapon3SkinIndex == 0 ) // default skin
 		weapon3AppearanceImage = $"rui/menu/common/appearance_button_swatch"
 	else if ( loadout.weapon3SkinIndex == 1 ) // camo
 		weapon3AppearanceImage = CamoSkin_GetImage( CamoSkins_GetByIndex( loadout.weapon3CamoIndex ) )
 	else // warpaint skin
-		weapon3AppearanceImage = GetItemImage( GetSkinRefFromWeaponRefAndPersistenceValue( loadout.weapon3, loadout.weapon3SkinIndex ) )
+		weapon3AppearanceImage = GetItemImageFromWeaponRefAndPersistenceValue( loadout.weapon3, loadout.weapon3SkinIndex, "weapon3SkinIndex" )
 
 	RuiSetImage( Hud_GetRui( Hud_GetChild( loadoutPanel, "ButtonPilotCamo" ) ), "camoImage", pilotAppearanceImage )
 	RuiSetImage( Hud_GetRui( Hud_GetChild( loadoutPanel, "ButtonPrimarySkin" ) ), "camoImage", primaryAppearanceImage )
@@ -282,3 +282,19 @@ void function UpdatePilotLoadoutPanelBinds( var loadoutPanel )
 	//SetLabelRuiText( Hud_GetChild( loadoutPanel, "TacticalBind" ), Localize( "%offhand1%" ) )
 	//SetLabelRuiText( Hud_GetChild( loadoutPanel, "OrdnanceBind" ), Localize( "%offhand0%" ) )
 }
+
+asset function GetItemImageFromWeaponRefAndPersistenceValue(string weaponRef, int persistenceValue, string loadoutProperty)
+{
+	string skinRef = GetSkinRefFromWeaponRefAndPersistenceValue( weaponRef, persistenceValue )
+	if (!IsRefValid(skinRef))
+	{
+		if (uiGlobal.editingLoadoutIndex != -1)
+		{
+			printt( "Resetting invalid " + loadoutProperty + " for weapon " + weaponRef )
+			SetCachedLoadoutValue(GetUIPlayer(), "pilot", uiGlobal.editingLoadoutIndex, loadoutProperty, "0")
+		}
+		return $"rui/menu/common/appearance_button_swatch"
+	}
+
+	return GetItemImage( skinRef )
+}