The CreateObject optional-tail walker previously stopped at UseRadius (~20 fields
before IconOverlay). This left ItemInstance.IconOverlayId/IconUnderlayId always 0,
so IconComposer's underlay/overlay layers were never drawn on toolbar icons.
Exact field order verified against ACE WorldObject_Networking.cs:87-219 (the
serializer is the authority; acdream connects to a local ACE server):
UseRadius → TargetType(u32) → UiEffects(u32) → CombatUse(sbyte) →
Structure(u16) → MaxStructure(u16) → StackSize(u16) → MaxStackSize(u16) →
Container(u32) → Wielder(u32) → ValidLocations(u32) →
CurrentlyWieldedLocation(u32) → Priority(u32) → RadarBlipColor(u8) →
RadarBehavior(u8) → PScript(u16) → Workmanship(f32) → Burden(u16) →
Spell(u16) → HouseOwner(u32) → HouseRestrictions(variable RestrictionDB) →
HookItemTypes(u32) → Monarch(u32) → HookType(u16) →
IconOverlay(PackedDwordKnownType) ← CAPTURE →
IconUnderlay from weenieFlags2 bit 0x01 ← CAPTURE
RestrictionDB handled correctly: Version(u32) + OpenStatus(u32) + MonarchId(u32)
+ count(u16) + numBuckets(u16) + count×8 bytes entries. Length-aware skip, not a
fixed constant.
weenieFlags2 is now CAPTURED (not skipped) when IncludesSecondHeader
(objDescFlags bit 0x04000000) is set, so the IconUnderlay bit can be tested.
The entire extended walk is inside try/catch: truncated packets degrade to
IconOverlayId=0 / IconUnderlayId=0 (no overlay drawn), never corrupting.
Threading: CreateObject.Parsed → WorldSession.EntitySpawn → GameWindow
OnLiveEntitySpawned → Items.EnrichItem — both ids thread through all three
seams. EnrichItem extended with optional iconOverlayId + iconUnderlayId params
(defaulted 0, backward-compatible).
No change to IconComposer or ToolbarController (they already consume the ids).
Tests: 4 new CreateObject tests (IconOverlay only, overlay+underlay, no-overlay
regression, intermediate-fields cursor arithmetic). Full suite: 0 failures,
2636 passed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>