Core/Auras: fixed off by one error in counting SPELL_ATTR5_START_PERIODIC_AT_APPLY ticks

- Made SpellInfo::GetMaxTicks and AuraEffect::GetTotalTicks return the same number without mods (dumped arbitrary default return value of 6 and arbitrary 30 sec limit)
- They should be streamlined whenever SPELL_AURA_48 is implemented

(cherry picked from commit 7dff0e3246f68c39e122e6ccb93b18c29f6df130)

3 files changed, 46 insertions, 25 deletions

diff --git a/src/server/game/Spells/Auras/SpellAuraEffects.cpp b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
index 8132912170a..797c0ce72bf 100644
--- a/src/server/game/Spells/Auras/SpellAuraEffects.cpp
+++ b/src/server/game/Spells/Auras/SpellAuraEffects.cpp
@@ -672,15 +672,28 @@ int32 AuraEffect::CalculateAmount(Unit* caster)
     return amount;
 }
 
+uint32 AuraEffect::GetTotalTicks() const
+{
+    uint32 totalTicks = 0;
+    if (_period && !GetBase()->IsPermanent())
+    {
+        totalTicks = static_cast<uint32>(GetBase()->GetMaxDuration() / _period);
+        if (m_spellInfo->HasAttribute(SPELL_ATTR5_START_PERIODIC_AT_APPLY))
+            ++totalTicks;
+    }
+
+    return totalTicks;
+}
+
 void AuraEffect::ResetPeriodic(bool resetPeriodicTimer /*= false*/)
 {
     _ticksDone = 0;
     if (resetPeriodicTimer)
     {
-        _periodicTimer = _period;
+        _periodicTimer = 0;
         // Start periodic on next tick or at aura apply
-        if (!m_spellInfo->HasAttribute(SPELL_ATTR5_START_PERIODIC_AT_APPLY))
-            _periodicTimer = 0;
+        if (m_spellInfo->HasAttribute(SPELL_ATTR5_START_PERIODIC_AT_APPLY))
+            _periodicTimer = _period;
     }
 }
 
@@ -947,27 +960,29 @@ void AuraEffect::ApplySpellMod(Unit* target, bool apply)
 
 void AuraEffect::Update(uint32 diff, Unit* caster)
 {
-    if (m_isPeriodic && (GetBase()->GetDuration() >= 0 || GetBase()->IsPassive() || GetBase()->IsPermanent()))
+    if (!m_isPeriodic || (GetBase()->GetDuration() < 0 && !GetBase()->IsPassive() && !GetBase()->IsPermanent()))
+        return;
+
+    uint32 totalTicks = GetTotalTicks();
+
+    _periodicTimer += diff;
+    while (_periodicTimer >= _period)
     {
-        _periodicTimer += diff;
-        while (_periodicTimer >= _period)
-        {
-            _periodicTimer -= _period;
+        _periodicTimer -= _period;
 
-            if (!GetBase()->IsPermanent() && (_ticksDone + 1) > GetTotalTicks())
-                break;
+        if (!GetBase()->IsPermanent() && (_ticksDone + 1) > totalTicks)
+            break;
 
-            ++_ticksDone;
+        ++_ticksDone;
 
-            GetBase()->CallScriptEffectUpdatePeriodicHandlers(this);
+        GetBase()->CallScriptEffectUpdatePeriodicHandlers(this);
 
-            std::vector<AuraApplication*> effectApplications;
-            GetApplicationList(effectApplications);
+        std::vector<AuraApplication*> effectApplications;
+        GetApplicationList(effectApplications);
 
-            // tick on targets of effects
-            for (AuraApplication* aurApp : effectApplications)
-                PeriodicTick(aurApp, caster);
-        }
+        // tick on targets of effects
+        for (AuraApplication* aurApp : effectApplications)
+            PeriodicTick(aurApp, caster);
     }
 }
 
diff --git a/src/server/game/Spells/Auras/SpellAuraEffects.h b/src/server/game/Spells/Auras/SpellAuraEffects.h
index c2e5ae24759..6503878de89 100644
--- a/src/server/game/Spells/Auras/SpellAuraEffects.h
+++ b/src/server/game/Spells/Auras/SpellAuraEffects.h
@@ -81,11 +81,11 @@ class TC_GAME_API AuraEffect
 
         void Update(uint32 diff, Unit* caster);
 
-        void ResetTicks() { _ticksDone = 0; }
         uint32 GetTickNumber() const { return _ticksDone; }
         uint32 GetRemainingTicks() const { return GetTotalTicks() - _ticksDone; }
-        uint32 GetTotalTicks() const { return (_period && !GetBase()->IsPermanent()) ? uint32(GetBase()->GetMaxDuration() / _period) : uint32(0); }
+        uint32 GetTotalTicks() const;
         void ResetPeriodic(bool resetPeriodicTimer = false);
+        void ResetTicks() { _ticksDone = 0; }
 
         bool IsPeriodic() const { return m_isPeriodic; }
         void SetPeriodic(bool isPeriodic) { m_isPeriodic = isPeriodic; }
diff --git a/src/server/game/Spells/SpellInfo.cpp b/src/server/game/Spells/SpellInfo.cpp
index 53a732c1390..38ec721e822 100644
--- a/src/server/game/Spells/SpellInfo.cpp
+++ b/src/server/game/Spells/SpellInfo.cpp
@@ -3722,13 +3722,13 @@ uint32 SpellInfo::CalcCastTime(Spell* spell /*= nullptr*/) const
 
 uint32 SpellInfo::GetMaxTicks() const
 {
+    uint32 totalTicks = 0;
     int32 DotDuration = GetDuration();
-    if (DotDuration == 0)
-        return 1;
 
     for (SpellEffectInfo const* effect : _effects)
     {
         if (effect && effect->Effect == SPELL_EFFECT_APPLY_AURA)
+        {
             switch (effect->ApplyAuraName)
             {
                 case SPELL_AURA_PERIODIC_DAMAGE:
@@ -3745,13 +3745,19 @@ uint32 SpellInfo::GetMaxTicks() const
                 case SPELL_AURA_PERIODIC_TRIGGER_SPELL:
                 case SPELL_AURA_PERIODIC_TRIGGER_SPELL_WITH_VALUE:
                 case SPELL_AURA_PERIODIC_HEALTH_FUNNEL:
-                    if (effect->ApplyAuraPeriod != 0)
-                        return DotDuration / effect->ApplyAuraPeriod;
+                    // skip infinite periodics
+                    if (effect->ApplyAuraPeriod > 0 && DotDuration > 0)
+                    {
+                        totalTicks = static_cast<uint32>(DotDuration) / effect->ApplyAuraPeriod;
+                        if (HasAttribute(SPELL_ATTR5_START_PERIODIC_AT_APPLY))
+                            ++totalTicks;
+                    }
                     break;
             }
+        }
     }
 
-    return 6;
+    return totalTicks;
 }
 
 uint32 SpellInfo::GetRecoveryTime() const