loot: add C_LootHistory (group-loot roll history backport)

Backport of the MoP C_LootHistory namespace. Vanilla 1.12 has no
loot-history store, but it receives the live group-loot roll traffic,
which the stock UI only turns into chat. This reconstructs the history
client-side (like Aura::Source): four co-hooks on the loot-roll packet
handlers accumulate a ring (128) of rolled items with per-player
Need/Greed/Pass results and the winner, exposed through the namespace.

Handlers, from the opcode dispatch FUN_005E6010:
  - START_ROLL  0x2A1 FUN_0061B310 (__fastcall(packet), RET 0)
  - ALL_PASSED  0x29E FUN_0061B640 (msg=EDX, RET 0)
  - ROLL_WON    0x29F FUN_0061B9E0 (ctx=ECX, msg=EDX, +stack, RET 4)
  - ROLL        0x2A2 FUN_0061C0B0 (msg=ECX, ctx=EDX, +stack, RET 4)
The per-handler ABI (message register, stack arg, RET) is load-bearing:
matching it exactly is what keeps the co-hooks from corrupting ESP.

Names and class come from the engine NameCache (FUN_0055F080, null-
callback read of a loaded entry), captured at roll time — so they
resolve even for a roller who has left the group by the time their roll
arrives. The item's random suffix is only in SMSG_LOOT_START_ROLL (the
result packets send 0), so it's read off the store-head node right after
that handler runs, giving a correct item:id:0:suffix:unique link.

Surface: C_LootHistory.GetNumItems / GetItem / GetPlayerInfo (name,
class token, rollType, roll, isWinner, isMe) + LOOT_HISTORY_ROLL_CHANGED
/ _ROLL_COMPLETE events (_FULL_UPDATE reserved). The MoP master-loot
functions (SetExpiration / GiveMasterLoot / CanMasterLoot) are omitted —
they need server support 1.12 lacks. Documented in docs/API.md + README.

Author: brues-code

README.md

@@ -43,6 +43,7 @@ Full per-function reference: **[docs/API.md](docs/API.md)**.
 | [Instance](docs/API.md#instance) | `GetInstanceInfo` |
 | [Item](docs/API.md#item) | `C_Item.DoesItemExist`, `C_Item.DoesItemExistByID`, `C_Item.EquipItemByName`, `C_Item.GetCurrentItemLevel`, `C_Item.GetDetailedItemLevelInfo`, `C_Item.GetEnchantInfo`, `C_Item.GetItemCount`, `C_Item.GetItemFamily`, `C_Item.GetItemGUID`, `C_Item.GetItemIcon`, `C_Item.GetItemIconByID`, `C_Item.GetItemID`, `C_Item.GetItemInfoInstant`, `C_Item.GetItemInventorySlotInfo`, `C_Item.GetItemInventorySlotKey`, `C_Item.GetItemInventoryType`, `C_Item.GetItemInventoryTypeByID`, `C_Item.GetItemLink`, `C_Item.GetItemLocation`, `C_Item.GetItemMaxStackSize`, `C_Item.GetItemMaxStackSizeByID`, `C_Item.GetItemName`, `C_Item.GetItemNameByID`, `C_Item.GetItemQuality`, `C_Item.GetItemQualityByID`, `C_Item.GetItemSellPrice`, `C_Item.GetItemSellPriceByID`, `C_Item.GetItemSetID`, `C_Item.GetItemSetIDByID`, `C_Item.GetItemSetInfo`, `C_Item.GetItemSpell`, `C_Item.GetItemStatDelta`, `C_Item.GetItemStats`, `C_Item.GetItemSubClassInfo`, `C_Item.GetItemUniqueness`, `C_Item.GetItemUniquenessByID`, `C_Item.GetStackCount`, `C_Item.GetWeaponEnchantInfo`, `C_Item.IsBound`, `C_Item.IsEquippableItem`, `C_Item.IsEquippedItem`, `C_Item.IsItemDataCached`, `C_Item.IsItemDataCachedByID`, `C_Item.IsItemGUIDInInventory`, `C_Item.IsItemOpenable`, `C_Item.IsLocked`, `C_Item.LockItem`, `C_Item.LockItemByGUID`, `C_Item.UnlockAllItems`, `C_Item.UnlockItem`, `C_Item.RequestLoadItemData`, `C_Item.RequestLoadItemDataByID`, `C_Item.UseAtCursor`, `C_Item.UseAtUnit`, `C_Item.UseItemByName`, `GetAuctionItemID`, `GetAuctionSellItemID`, `GetAverageItemLevel`, `GetCraftReagentItemID`, `GetInboxItemID`, `GetInventoryItemDurability`, `GetInventoryItemID`, `GetInventoryItemsForSlot`, `GetInventoryItemRepairCost`, `GetItemIcon`, `GetLootRollItemID`, `GetLootSlotItemID`, `GetMerchantItemID`, `GetQuestItemID`, `GetQuestLogItemID`, `GetTradePlayerItemID`, `GetTradeSkillItemID`, `GetTradeSkillReagentItemID`, `GetTradeTargetItemID`, `OffhandHasWeapon` |
 | [Loot](docs/API.md#loot) | `C_Loot.GetNearbyLootableUnits`, `C_Loot.GetLastScanResults`, `C_Loot.IsScanInProgress`, `C_Loot.LootUnit`, `C_Loot.LootUnitItem`, `C_Loot.ScanNearbyLoot` |
+| [LootHistory](docs/API.md#loothistory) | `C_LootHistory.GetNumItems`, `C_LootHistory.GetItem`, `C_LootHistory.GetPlayerInfo` |
 | [LossOfControl](docs/API.md#lossofcontrol) | `C_LossOfControl.GetActiveLossOfControlData`, `C_LossOfControl.GetActiveLossOfControlDataCount` |
 | [Macros](docs/API.md#macros) | `GetLooseMacroIcons`, `GetLooseMacroItemIcons`, `GetMacroIcons`, `GetMacroItemIcons`, `GetMacroSpell` |
 | [Mail](docs/API.md#mail) | `GetInboxItemLink`, `GetSendMailItemLink` |
@@ -121,6 +122,8 @@ when launching with `-console`), not as Lua functions. See the
 | `GLOBAL_MOUSE_UP` | `button` |
 | `HEARTHSTONE_BOUND` | *(none)* |
 | `ITEM_DATA_LOAD_RESULT` | `itemID, success` |
+| `LOOT_HISTORY_ROLL_CHANGED` | `itemIndex, playerIndex` |
+| `LOOT_HISTORY_ROLL_COMPLETE` | `itemIndex` |
 | `LOOT_SCAN_COMPLETED` | *(none)* |
 | `LOSS_OF_CONTROL_ADDED` | `eventIndex` |
 | `LOSS_OF_CONTROL_UPDATE` | `unitToken` (always `"player"`) |

docs/API.md

@@ -99,6 +99,7 @@ build instructions.
   - [`EQUIPMENT_SWAP_PENDING` event](#equipment_swap_pending-event)
   - [`EQUIPMENT_SWAP_FINISHED` event](#equipment_swap_finished-event)
   - [`FACTION_STANDING_CHANGED` event](#faction_standing_changed-event)
+  - [`LOOT_HISTORY_ROLL_CHANGED` / `LOOT_HISTORY_ROLL_COMPLETE` / `LOOT_HISTORY_FULL_UPDATE` events](#loot_history_roll_changed--loot_history_roll_complete--loot_history_full_update-events)
   - [`LOOT_SCAN_COMPLETED` event](#loot_scan_completed-event)
   - [`LOSS_OF_CONTROL_ADDED` / `LOSS_OF_CONTROL_UPDATE` events](#loss_of_control_added--loss_of_control_update-events)
   - [`MODIFIER_STATE_CHANGED` event](#modifier_state_changed-event)
@@ -255,6 +256,11 @@ build instructions.
   - [`C_Loot.IsScanInProgress()`](#c_lootisscaninprogress)
   - [`C_Loot.GetLastScanResults()`](#c_lootgetlastscanresults)
 
+- [LootHistory](#loothistory)
+  - [`C_LootHistory.GetNumItems()`](#c_loothistorygetnumitems)
+  - [`C_LootHistory.GetItem(itemIndex)`](#c_loothistorygetitemitemindex)
+  - [`C_LootHistory.GetPlayerInfo(itemIndex, playerIndex)`](#c_loothistorygetplayerinfoitemindex-playerindex)
+
 - [LossOfControl](#lossofcontrol)
   - [`C_LossOfControl.GetActiveLossOfControlDataCount()`](#c_lossofcontrolgetactivelossofcontroldatacount)
   - [`C_LossOfControl.GetActiveLossOfControlData(index)`](#c_lossofcontrolgetactivelossofcontroldataindex)
@@ -2295,6 +2301,22 @@ forwarding, which [`C_Reputation.GetLastStandingChange`](#c_reputationgetlaststa
 exposes — so addons can read the structured payload from inside the
 chat event without re-parsing the localized string.
 
+### `LOOT_HISTORY_ROLL_CHANGED` / `LOOT_HISTORY_ROLL_COMPLETE` / `LOOT_HISTORY_FULL_UPDATE` events
+
+Fire as group-loot rolls progress, so a loot-history UI can update without
+polling. Register like any engine event
+(`frame:RegisterEvent("LOOT_HISTORY_ROLL_COMPLETE")`), then read the item via
+[`C_LootHistory.GetItem`](#c_loothistorygetitemitemindex) /
+[`C_LootHistory.GetPlayerInfo`](#c_loothistorygetplayerinfoitemindex-playerindex).
+
+| Event | Args | When |
+|---|---|---|
+| `LOOT_HISTORY_ROLL_CHANGED` | `itemIndex`, `playerIndex` (numbers) | A player rolled or passed on an item. |
+| `LOOT_HISTORY_ROLL_COMPLETE` | `itemIndex` (number) | The item was decided — won or all-passed. |
+| `LOOT_HISTORY_FULL_UPDATE` | — | Reserved for API / `IsEventValid` completeness (the display frame fires it on open); the DLL doesn't dispatch it. |
+
+See the [LootHistory](#loothistory) section for the reconstruction and read API.
+
 ### `LOOT_SCAN_COMPLETED` event
 
 Fires (no payload) once a [`C_Loot.ScanNearbyLoot()`](#c_lootscannearbyloot)
@@ -6125,6 +6147,57 @@ tooltip display, extract the payload form via
 requires the literal `"item:"` prefix and rejects full `|cff...|Hitem...|h`
 input.
 
+## LootHistory
+
+Backport of the MoP `C_LootHistory` namespace — group-loot roll history.
+Vanilla 1.12 has no loot-history store, but it does receive the live
+group-loot roll traffic (`SMSG_LOOT_ROLL` per player, `SMSG_LOOT_ROLL_WON`,
+`SMSG_LOOT_ALL_PASSED`) — which the stock UI only turns into chat lines. This
+reconstructs the history client-side: packet co-hooks accumulate a ring of
+rolled items with per-player Need/Greed/Pass results and the winner, exposed
+through the namespace. Rollers' **name and class come from the engine
+NameCache** captured at roll time, so they resolve even for a player who has
+left the group by the time their roll arrives.
+
+History is in-memory (last 128 rolled items) and resets on `/reload` or logout.
+The MoP master-loot management functions (`SetExpiration` / `GiveMasterLoot` /
+`CanMasterLoot`) are intentionally omitted — they drive server support 1.12
+doesn't have.
+
+Progress is signalled by the `LOOT_HISTORY_ROLL_CHANGED` /
+`LOOT_HISTORY_ROLL_COMPLETE` events — see the
+[Events](#loot_history_roll_changed--loot_history_roll_complete--loot_history_full_update-events)
+section.
+
+### `C_LootHistory.GetNumItems()`
+
+Returns the number of rolled items currently in the history.
+
+### `C_LootHistory.GetItem(itemIndex)`
+
+`1`-based. Returns `itemLink, numPlayers, isDone, winnerName`:
+- `itemLink` — `item:<id>:0:<suffix>:<unique>` (valid for `GetItemInfo` /
+  `GameTooltip:SetHyperlink`), carrying the roll's random suffix so
+  "of the X" items keep their affix.
+- `numPlayers` — how many players have rolled/passed so far.
+- `isDone` — `true` once the item is decided (won or all-passed).
+- `winnerName` — the winner's name, or `nil` if undecided / all passed.
+
+Returns nothing for an out-of-range index.
+
+### `C_LootHistory.GetPlayerInfo(itemIndex, playerIndex)`
+
+Both `1`-based. Returns `name, class, rollType, roll, isWinner, isMe`:
+- `name` — the roller's name (from the NameCache).
+- `class` — the class token (`"WARRIOR"`, `"MAGE"`, …) for
+  `RAID_CLASS_COLORS`, or `nil` if unknown.
+- `rollType` — `0` = pass, `1` = need, `2` = greed.
+- `roll` — the `1`–`100` roll, or `0` if they passed.
+- `isWinner` — `true` if this player won the item.
+- `isMe` — `true` if this roller is the local player.
+
+Returns nothing for an out-of-range item or player index.
+
 ## LossOfControl
 
 Backports `C_LossOfControl` — the active crowd-control / interrupt effects on

src/Offsets.h

@@ -1218,6 +1218,42 @@ enum Offsets {
     // aura that's still inside its computed duration window.
     FUN_ON_AURA_REMOVED = 0x00612320,
 
+    // Group-loot roll packet handlers (the inner display functions in
+    // LootRoll.cpp). Each is `__fastcall`; the deserialized 0x48-byte
+    // PendingLootRoll message struct is fully populated at entry and freed
+    // at exit, so read its fields BEFORE calling the original. The register
+    // the message arrives in differs per handler (matched in
+    // loot/History.cpp): ROLL passes it in ECX, WON / ALL_PASSED in EDX.
+    // Backs the C_LootHistory backport (loot/History.cpp) — 1.12 has no
+    // loot-history store, so we reconstruct one from these packets.
+    FUN_LOOT_ROLL_HANDLER = 0x0061C0B0,       // SMSG_LOOT_ROLL       (msg=ECX)
+    FUN_LOOT_ROLL_WON_HANDLER = 0x0061B9E0,   // SMSG_LOOT_ROLL_WON   (msg=EDX)
+    FUN_LOOT_ALL_PASSED_HANDLER = 0x0061B640, // SMSG_LOOT_ALL_PASSED (msg=EDX)
+
+    // SMSG_LOOT_START_ROLL (opcode 0x2A1) handler — `__fastcall(ECX = packet)`,
+    // RET 0. The result packets (ROLL/WON/PASSED) carry 0 for the item's
+    // random suffix/seed; only START_ROLL does. It deserializes a fresh
+    // PendingLootRoll node (same 0x20/0x24 field offsets as the message) and
+    // publishes it as the store head at VAR_LOOTROLL_STORE_HEAD, so we read
+    // the suffix straight off that node right after the original runs.
+    FUN_LOOT_START_ROLL_HANDLER = 0x0061B310,
+    VAR_LOOTROLL_STORE_HEAD = 0x00C4DC00, // PendingLootRoll* — newest node
+
+    // PendingLootRoll message field offsets, derived from the SMSG_LOOT_ROLL
+    // deserializer FUN_0061BFA0 (reads GUID/u32/byte fields off the packet).
+    OFF_LOOTROLL_SOURCE_GUID = 0x10, // u64 looted-object GUID (roll identity)
+    OFF_LOOTROLL_SLOT = 0x18,        // u32 loot slot
+    OFF_LOOTROLL_ITEM_ID = 0x1C,     // u32 itemID
+    // Random-enchant fields for the item link `item:id:enchant:suffix:unique`.
+    // +0x20 is the suffix/random-property ID the engine's item-name builder
+    // FUN_005D8B00 uses (indexes the random-properties DBC for the "of the X"
+    // name); +0x24 is the paired seed/unique value.
+    OFF_LOOTROLL_ITEM_SUFFIX = 0x20, // i32 random suffix / property ID
+    OFF_LOOTROLL_ITEM_SEED = 0x24,   // u32 random seed (link unique field)
+    OFF_LOOTROLL_ROLLER_GUID = 0x30, // u64 roller / winner GUID
+    OFF_LOOTROLL_ROLL_NUM = 0x38,    // u8 roll (1..100); high bit = didn't roll
+    OFF_LOOTROLL_ROLL_TYPE = 0x40,   // u32 rollType: 0 = need, 2 = greed
+
     // CGPlayer-side sub-struct, allocated for any player-controlled
     // unit (local self, target, party, raid, inspect targets — all of
     // them). Holds player-specific data that's *not* in the broadcast