Core/Spells: Cleanup movement checks in spells - use correct interrupt flags

src/server/game/Entities/Creature/Creature.cpp

@@ -3363,7 +3363,7 @@ bool Creature::IsMovementPreventedByCasting() const
     if (Spell* spell = m_currentSpells[CURRENT_CHANNELED_SPELL])
     {
         if (spell->getState() != SPELL_STATE_FINISHED && spell->IsChannelActive())
-            if (spell->GetSpellInfo()->IsMoveAllowedChannel())
+            if (spell->CheckMovement() != SPELL_CAST_OK)
                 return false;
     }
 

src/server/game/Entities/Unit/Unit.cpp

@@ -2784,8 +2784,7 @@ void Unit::_UpdateAutoRepeatSpell()
 
     // check "realtime" interrupts
     // don't cancel spells which are affected by a SPELL_AURA_CAST_WHILE_WALKING effect
-    if (((GetTypeId() == TYPEID_PLAYER && ToPlayer()->isMoving()) || IsNonMeleeSpellCast(false, false, true, autoRepeatSpellInfo->Id == 75)) &&
-        !CanCastSpellWhileMoving(autoRepeatSpellInfo))
+    if ((isMoving() && m_currentSpells[CURRENT_AUTOREPEAT_SPELL]->CheckMovement() != SPELL_CAST_OK) || IsNonMeleeSpellCast(false, false, true, autoRepeatSpellInfo->Id == 75))
     {
         // cancel wand shoot
         if (autoRepeatSpellInfo->Id != 75)
@@ -3015,7 +3014,7 @@ bool Unit::IsMovementPreventedByCasting() const
     // channeled spells during channel stage (after the initial cast timer) allow movement with a specific spell attribute
     if (Spell* spell = m_currentSpells[CURRENT_CHANNELED_SPELL])
         if (spell->getState() != SPELL_STATE_FINISHED && spell->IsChannelActive())
-            if (spell->GetSpellInfo()->IsMoveAllowedChannel())
+            if (spell->GetSpellInfo()->IsMoveAllowedChannel() || CanCastSpellWhileMoving(spell->GetSpellInfo()))
                 return false;
 
     // prohibit movement for all other spell casts

src/server/game/Spells/Spell.cpp

@@ -3375,19 +3375,14 @@ SpellCastResult Spell::prepare(SpellCastTargets const& targets, AuraEffect const
     else
         m_casttime = m_spellInfo->CalcCastTime(this);
 
-    // don't allow channeled spells / spells with cast time to be cast while moving
-    // exception are only channeled spells that have no casttime and dont have movement interrupt flag
-    // (even if they are interrupted on moving, spells with almost immediate effect get to have their effect processed before movement interrupter kicks in)
-    // don't cancel spells which are affected by a SPELL_AURA_CAST_WHILE_WALKING effect
-    if (((m_spellInfo->IsChanneled() || m_casttime) && m_caster->GetTypeId() == TYPEID_PLAYER && !(m_caster->ToUnit()->IsCharmed() && m_caster->ToUnit()->GetCharmerGUID().IsCreature()) && m_caster->ToUnit()->isMoving() &&
-        m_spellInfo->InterruptFlags.HasFlag(SpellInterruptFlags::Movement)) && !m_caster->ToUnit()->CanCastSpellWhileMoving(m_spellInfo))
+    if (m_caster->IsUnit() && m_caster->ToUnit()->isMoving())
     {
-        // 1. Has casttime, 2. Or doesn't have flag to allow movement during channel
-        if (m_casttime || !m_spellInfo->IsMoveAllowedChannel())
+        result = CheckMovement();
+        if (result != SPELL_CAST_OK)
         {
-            SendCastResult(SPELL_FAILED_MOVING);
+            SendCastResult(result);
             finish(false);
-            return SPELL_FAILED_MOVING;
+            return result;
         }
     }
 
@@ -4110,20 +4105,13 @@ void Spell::update(uint32 difftime)
 
     // check if the player caster has moved before the spell finished
     // with the exception of spells affected with SPELL_AURA_CAST_WHILE_WALKING effect
-    if ((m_caster->GetTypeId() == TYPEID_PLAYER && m_timer != 0) &&
-        m_caster->ToUnit()->isMoving() && (m_spellInfo->InterruptFlags.HasFlag(SpellInterruptFlags::Movement)) &&
-        (!m_spellInfo->HasEffect(SPELL_EFFECT_STUCK) || !m_caster->ToUnit()->HasUnitMovementFlag(MOVEMENTFLAG_FALLING_FAR)) &&
-        !m_caster->ToUnit()->CanCastSpellWhileMoving(m_spellInfo))
+    if (m_timer != 0 && m_caster->IsUnit() && m_caster->ToUnit()->isMoving() && CheckMovement() != SPELL_CAST_OK)
     {
-        // don't cancel for melee, autorepeat, triggered and instant spells
-        if (!m_spellInfo->IsNextMeleeSwingSpell() && !IsAutoRepeat() && !IsTriggered() && !(IsChannelActive() && m_spellInfo->IsMoveAllowedChannel()))
-        {
-            // if charmed by creature, trust the AI not to cheat and allow the cast to proceed
-            // @todo this is a hack, "creature" movesplines don't differentiate turning/moving right now
-            // however, checking what type of movement the spline is for every single spline would be really expensive
-            if (!m_caster->ToUnit()->GetCharmerGUID().IsCreature())
-                cancel();
-        }
+        // if charmed by creature, trust the AI not to cheat and allow the cast to proceed
+        // @todo this is a hack, "creature" movesplines don't differentiate turning/moving right now
+        // however, checking what type of movement the spline is for every single spline would be really expensive
+        if (!m_caster->ToUnit()->GetCharmerGUID().IsCreature())
+            cancel();
     }
 
     switch (m_spellState)
@@ -5579,19 +5567,6 @@ SpellCastResult Spell::CheckCast(bool strict, int32* param1 /*= nullptr*/, int32
                 return SPELL_FAILED_AFFECTING_COMBAT;
         }
 
-        // cancel autorepeat spells if cast start when moving
-        // (not wand currently autorepeat cast delayed to moving stop anyway in spell update code)
-        // Do not cancel spells which are affected by a SPELL_AURA_CAST_WHILE_WALKING effect
-        if (unitCaster->GetTypeId() == TYPEID_PLAYER && unitCaster->ToPlayer()->isMoving()
-            && (!unitCaster->IsCharmed() || !unitCaster->GetCharmerGUID().IsCreature())
-            && !unitCaster->CanCastSpellWhileMoving(m_spellInfo))
-        {
-            // skip stuck spell to allow use it in falling case and apply spell limitations at movement
-            if ((!unitCaster->HasUnitMovementFlag(MOVEMENTFLAG_FALLING_FAR) || !m_spellInfo->HasEffect(SPELL_EFFECT_STUCK)) &&
-                (IsAutoRepeat() || m_spellInfo->HasAuraInterruptFlag(SpellAuraInterruptFlags::Standing)))
-                return SPELL_FAILED_MOVING;
-        }
-
         // Check vehicle flags
         if (!(_triggeredCastFlags & TRIGGERED_IGNORE_CASTER_MOUNTED_OR_ON_VEHICLE))
         {
@@ -6861,6 +6836,32 @@ SpellCastResult Spell::CheckArenaAndRatedBattlegroundCastRules()
     return SPELL_CAST_OK;
 }
 
+SpellCastResult Spell::CheckMovement() const
+{
+    if (IsTriggered())
+        return SPELL_CAST_OK;
+
+    if (Unit* unitCaster = m_caster->ToUnit())
+    {
+        if (!unitCaster->CanCastSpellWhileMoving(m_spellInfo))
+        {
+            if (m_casttime)
+            {
+                if (m_spellInfo->InterruptFlags.HasFlag(SpellInterruptFlags::Movement))
+                    return SPELL_FAILED_MOVING;
+            }
+            else
+            {
+                // only fail channeled casts if they are instant but cannot be channeled while moving
+                if (m_spellInfo->IsChanneled() && !m_spellInfo->IsMoveAllowedChannel())
+                    return SPELL_FAILED_MOVING;
+            }
+        }
+    }
+
+    return SPELL_CAST_OK;
+}
+
 int32 Spell::CalculateDamage(SpellEffectInfo const& spellEffectInfo, Unit const* target, float* var /*= nullptr*/) const
 {
     bool needRecalculateBasePoints = !(m_spellValue->CustomBasePointsMask & (1 << spellEffectInfo.EffectIndex));

src/server/game/Spells/Spell.h

@@ -464,6 +464,7 @@ class TC_GAME_API Spell
         SpellCastResult CheckRuneCost() const;
         SpellCastResult CheckCasterAuras(int32* param1) const;
         SpellCastResult CheckArenaAndRatedBattlegroundCastRules();
+        SpellCastResult CheckMovement() const;
 
         bool CheckSpellCancelsAuraEffect(AuraType auraType, int32* param1) const;
         bool CheckSpellCancelsCharm(int32* param1) const;