From 89deb60d43cb4aa1c51214db9ad423b65f94f522 Mon Sep 17 00:00:00 2001
From: UltraNix <80540499+UltraNix@users.noreply.github.com>
Date: Sat, 12 Feb 2022 15:51:27 +0100
Subject: [PATCH] fix(Core/Spells): Flasks should not be overridden by elixirs.
 (#10301)

* fix(Core/Spells): Flasks should not be overridden by elixirs.
---
 src/server/game/Entities/Player/Player.cpp |  8 ++++
 src/server/game/Spells/SpellInfo.cpp       | 47 ++++++++++++++++++++++
 src/server/game/Spells/SpellInfo.h         |  2 +
 src/server/game/Spells/SpellMgr.h          |  9 ++++-
 4 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 5a535413c..1bc0833cf 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -7279,7 +7279,15 @@ void Player::CastItemUseSpell(Item* item, SpellCastTargets const& targets, uint8
         }
 
         if (HasSpellCooldown(spellInfo->Id))
+        {
             continue;
+        }
+
+        if (!spellInfo->CheckElixirStacking(this))
+        {
+            Spell::SendCastResult(this, spellInfo, cast_count, SPELL_FAILED_AURA_BOUNCED);
+            continue;
+        }
 
         Spell* spell = new Spell(this, spellInfo, (count > 0) ? TRIGGERED_FULL_MASK : TRIGGERED_NONE);
         spell->m_CastItem = item;
diff --git a/src/server/game/Spells/SpellInfo.cpp b/src/server/game/Spells/SpellInfo.cpp
index 05a97eed7..e251e8207 100644
--- a/src/server/game/Spells/SpellInfo.cpp
+++ b/src/server/game/Spells/SpellInfo.cpp
@@ -2844,3 +2844,50 @@ void SpellInfo::_UnloadImplicitTargetConditionLists()
         delete cur;
     }
 }
+
+bool SpellInfo::CheckElixirStacking(Unit const* caster) const
+{
+    if (!caster)
+    {
+        return true;
+    }
+
+    // xinef: check spell group
+    uint32 groupId = sSpellMgr->GetSpellGroup(Id);
+    if (groupId != SPELL_GROUP_GUARDIAN_AND_BATTLE_ELIXIRS)
+    {
+        return true;
+    }
+
+    SpellGroupSpecialFlags sFlag = sSpellMgr->GetSpellGroupSpecialFlags(Id);
+    for (uint8 i = EFFECT_0; i < MAX_SPELL_EFFECTS; ++i)
+    {
+        if (!Effects[i].IsAura())
+        {
+            continue;
+        }
+
+        Unit::AuraApplicationMap const& Auras = caster->GetAppliedAuras();
+        for (Unit::AuraApplicationMap::const_iterator itr = Auras.begin(); itr != Auras.end(); ++itr)
+        {
+            // xinef: aura is not groupped or in different group
+            uint32 auraGroup = sSpellMgr->GetSpellGroup(itr->first);
+            if (auraGroup != groupId)
+            {
+                continue;
+            }
+
+            // Cannot apply guardian/battle elixir if flask is present
+            if (sFlag == SPELL_GROUP_SPECIAL_FLAG_ELIXIR_BATTLE || sFlag == SPELL_GROUP_SPECIAL_FLAG_ELIXIR_GUARDIAN)
+            {
+                SpellGroupSpecialFlags sAuraFlag = sSpellMgr->GetSpellGroupSpecialFlags(itr->first);
+                if ((sAuraFlag & SPELL_GROUP_SPECIAL_FLAG_FLASK) == SPELL_GROUP_SPECIAL_FLAG_FLASK)
+                {
+                    return false;
+                }
+            }
+        }
+    }
+
+    return true;
+}
diff --git a/src/server/game/Spells/SpellInfo.h b/src/server/game/Spells/SpellInfo.h
index 7f85461e4..4dfcef8ac 100644
--- a/src/server/game/Spells/SpellInfo.h
+++ b/src/server/game/Spells/SpellInfo.h
@@ -535,6 +535,8 @@ public:
     // unloading helpers
     void _UnloadImplicitTargetConditionLists();
 
+    bool CheckElixirStacking(Unit const* caster) const;
+
 private:
     std::array<SpellEffectInfo, MAX_SPELL_EFFECTS>& _GetEffects() { return Effects; }
     SpellEffectInfo& _GetEffect(SpellEffIndex index) { ASSERT(index < Effects.size()); return Effects[index]; }
diff --git a/src/server/game/Spells/SpellMgr.h b/src/server/game/Spells/SpellMgr.h
index 49e521a6a..52201a013 100644
--- a/src/server/game/Spells/SpellMgr.h
+++ b/src/server/game/Spells/SpellMgr.h
@@ -340,7 +340,9 @@ enum SpellGroupSpecialFlags
     SPELL_GROUP_SPECIAL_FLAG_PRIORITY4                  = 0x800,
     SPELL_GROUP_SPECIAL_FLAG_SAME_SPELL_CHECK           = 0x1000,
     SPELL_GROUP_SPECIAL_FLAG_SKIP_STRONGER_SAME_SPELL   = 0x2000,
-    SPELL_GROUP_SPECIAL_FLAG_MAX                        = 0x4000
+    SPELL_GROUP_SPECIAL_FLAG_MAX                        = 0x4000,
+
+    SPELL_GROUP_SPECIAL_FLAG_FLASK                      = SPELL_GROUP_SPECIAL_FLAG_ELIXIR_BATTLE | SPELL_GROUP_SPECIAL_FLAG_ELIXIR_GUARDIAN
 };
 
 enum SpellGroupStackFlags
@@ -358,6 +360,11 @@ enum SpellGroupStackFlags
     SPELL_GROUP_STACK_FLAG_FORCED_WEAKEST       = 0x200,
 };
 
+enum SpellGroupIDs
+{
+    SPELL_GROUP_GUARDIAN_AND_BATTLE_ELIXIRS     = 1
+};
+
 struct SpellStackInfo
 {
     uint32 groupId;