fix(Core/Battlefield): Restrict Within Our Grasp to attackers (#25945)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/server/game/Battlefield/BattlefieldMgr.cpp

@@ -112,6 +112,13 @@ Battlefield* BattlefieldMgr::GetBattlefieldByBattleId(uint32 battleId)
     return nullptr;
 }
 
+bool BattlefieldMgr::IsWintergraspAttackerVictory()
+{
+    if (Battlefield* bf = GetBattlefieldByBattleId(BATTLEFIELD_BATTLEID_WG))
+        return static_cast<BattlefieldWG*>(bf)->IsLastBattleAttackerVictory();
+    return false;
+}
+
 void BattlefieldMgr::Update(uint32 diff)
 {
     _updateTimer += diff;

src/server/game/Battlefield/BattlefieldMgr.h

@@ -47,6 +47,9 @@ public:
     Battlefield* GetBattlefieldToZoneId(uint32 zoneId);
     Battlefield* GetBattlefieldByBattleId(uint32 battleId);
 
+    // True iff the most recent Wintergrasp battle ended with the keep captured.
+    [[nodiscard]] bool IsWintergraspAttackerVictory();
+
     ZoneScript* GetZoneScript(uint32 zoneId);
 
     void AddZone(uint32 zoneId, Battlefield* handle);

src/server/game/Battlefield/Zones/BattlefieldWG.cpp

@@ -348,6 +348,9 @@ void BattlefieldWG::CapturePointTaken(uint32 areaId)
 
 void BattlefieldWG::OnBattleEnd(bool endByTimer)
 {
+    // Must be set before SPELL_VICTORY_REWARD so the 1755 criterion can gate on it.
+    LastBattleAttackerVictory = !endByTimer;
+
     // Remove relic
     if (GameObject* go = GetRelic())
         go->RemoveFromWorld();

src/server/game/Battlefield/Zones/BattlefieldWG.h

@@ -403,6 +403,9 @@ public:
 
     uint32 GetData(uint32 data) const override;
 
+    // True iff the most recent battle ended with the keep captured (attacker win).
+    [[nodiscard]] bool IsLastBattleAttackerVictory() const { return LastBattleAttackerVictory; }
+
     bool IsKeepNpc(uint32 entry)
     {
         switch (entry)
@@ -451,6 +454,8 @@ protected:
     int32 TenacityStack;
 
     ObjectGuid TitansRelic;
+
+    bool LastBattleAttackerVictory{false};
 };
 
 uint8 const WG_MAX_OBJ = 32;

src/server/scripts/Northrend/zone_wintergrasp.cpp

@@ -1160,6 +1160,10 @@ public:
         if (!wintergrasp)
             return false;
 
+        // Attacker-only achievement -- defenders winning fast must not qualify.
+        if (!sBattlefieldMgr->IsWintergraspAttackerVictory())
+            return false;
+
         return wintergrasp->GetTimer() >= (20 * MINUTE * IN_MILLISECONDS);
     }
 };