Core/Auras: Prevent assertion fail due code in AuraEffect::HandleAuraLinked, also improve the sync between auras linked by this aura type.

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -6554,25 +6554,38 @@ void AuraEffect::HandleAuraConvertRune(AuraApplication const * aurApp, uint8 mod
 
 void AuraEffect::HandleAuraLinked(AuraApplication const * aurApp, uint8 mode, bool apply) const
 {
-    if (!(mode & (AURA_EFFECT_HANDLE_REAL | AURA_EFFECT_HANDLE_REAPPLY)))
-        return;
-
     Unit * target = aurApp->GetTarget();
 
-    if (apply)
-    {
-        Unit * caster = GetTriggeredSpellCaster(m_spellProto, GetCaster(), target);
+    uint32 triggeredSpellId = m_spellProto->EffectTriggerSpell[m_effIndex];
 
-        if (!caster)
-            return;
-        // If amount avalible cast with basepoints (Crypt Fever for example)
-        if (GetAmount())
-            caster->CastCustomSpell(target, m_spellProto->EffectTriggerSpell[m_effIndex], &m_amount, NULL, NULL, true, NULL, this);
+    if (mode & AURA_EFFECT_HANDLE_REAL)
+    {
+        if (apply)
+        {
+            Unit * caster = GetTriggeredSpellCaster(m_spellProto, GetCaster(), target);
+
+            if (!caster)
+                return;
+            // If amount avalible cast with basepoints (Crypt Fever for example)
+            if (GetAmount())
+                caster->CastCustomSpell(target, triggeredSpellId, &m_amount, NULL, NULL, true, NULL, this);
+            else
+                caster->CastSpell(target, triggeredSpellId, true, NULL, this);
+        }
         else
-            caster->CastSpell(target, m_spellProto->EffectTriggerSpell[m_effIndex], true, NULL, this);
+        {
+            uint64 casterGUID = IsSpellRequiringFocusedTarget(GetSpellProto()) ? GetCasterGUID() : target->GetGUID();
+            target->RemoveAura(triggeredSpellId, casterGUID, 0, aurApp->GetRemoveMode());
+        }
+    }
+    else if (mode & AURA_EFFECT_HANDLE_REAPPLY && apply)
+    {
+        uint64 casterGUID = IsSpellRequiringFocusedTarget(GetSpellProto()) ? GetCasterGUID() : target->GetGUID();
+        
+        // change the stack amount to be equal to stack amount of our aura
+        if (Aura* triggeredAura = target->GetAura(triggeredSpellId, casterGUID))
+            triggeredAura->ModStackAmount(GetBase()->GetStackAmount() - triggeredAura->GetStackAmount());
     }
-    else
-        target->RemoveAura(m_spellProto->EffectTriggerSpell[m_effIndex], GetCasterGUID(), 0, AuraRemoveMode(aurApp->GetRemoveMode()));
 }
 
 void AuraEffect::HandleAuraOpenStable(AuraApplication const * aurApp, uint8 mode, bool apply) const

src/server/game/Spells/SpellMgr.cpp

@@ -427,7 +427,7 @@ uint32 CalculatePowerCost(SpellEntry const * spellInfo, Unit const * caster, Spe
     return powerCost;
 }
 
-Unit* GetTriggeredSpellCaster(SpellEntry const * spellInfo, Unit * caster, Unit * target)
+bool IsSpellRequiringFocusedTarget(SpellEntry const * spellInfo)
 {
     for (uint8 i = 0 ; i < MAX_SPELL_EFFECTS; ++i)
     {
@@ -437,8 +437,15 @@ Unit* GetTriggeredSpellCaster(SpellEntry const * spellInfo, Unit * caster, Unit
             || SpellTargetType[spellInfo->EffectImplicitTargetB[i]] == TARGET_TYPE_CHANNEL
             || SpellTargetType[spellInfo->EffectImplicitTargetA[i]] == TARGET_TYPE_DEST_TARGET
             || SpellTargetType[spellInfo->EffectImplicitTargetB[i]] == TARGET_TYPE_DEST_TARGET)
-            return caster;
+            return true;
     }
+
+}
+
+Unit* GetTriggeredSpellCaster(SpellEntry const * spellInfo, Unit * caster, Unit * target)
+{
+    if (IsSpellRequiringFocusedTarget(spellInfo))
+        return caster;
     return target;
 }
 

src/server/game/Spells/SpellMgr.h

@@ -173,6 +173,7 @@ enum SpellLinkedType
     SPELL_LINK_REMOVE   = 0,
 };
 
+bool IsSpellRequiringFocusedTarget(SpellEntry const * spellInfo);
 Unit * GetTriggeredSpellCaster(SpellEntry const * spellInfo, Unit * caster, Unit * target);
 SpellSpecific GetSpellSpecific(SpellEntry const * spellInfo);
 AuraState GetSpellAuraState(SpellEntry const * spellInfo);