Core/Spell: fix target checks

- Aura will be applied at last moment possible (after damage) to prevent regressions on #18395
- Partial revert of 9b38a6352c0fe2499de54fd769aa1c721a410bda as it wasnt handling correctly checks without spells

Closes #21578
Closes #21579
Closes #21581

(cherry picked from commit d6b9f148a772d07b9353a0db95a6f05c9c848a63)

1 files changed, 20 insertions, 18 deletions

diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index 45b53f6f93b..ceca13fdfdf 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -2382,6 +2382,7 @@ void Spell::TargetInfo::PreprocessTarget(Spell* spell)
             if (missInfo != SPELL_MISS_MISS)
                 spell->m_caster->ToUnit()->SendSpellMiss(unit, spell->m_spellInfo->Id, missInfo);
             spell->m_damage = 0;
+            spell->m_healing = 0;
             _spellHitTarget = nullptr;
         }
     }
@@ -2645,6 +2646,20 @@ void Spell::TargetInfo::DoDamageAndTriggers(Spell* spell)
         else if (spell->m_caster->GetTypeId() == TYPEID_GAMEOBJECT && spell->m_caster->ToGameObject()->AI())
             spell->m_caster->ToGameObject()->AI()->SpellHitTarget(_spellHitTarget, spell->m_spellInfo);
 
+        if (spell->_spellAura)
+        {
+            if (AuraApplication* aurApp = spell->_spellAura->GetApplicationOfTarget(_spellHitTarget->GetGUID()))
+            {
+                // only apply unapplied effects (for reapply case)
+                uint32 effMask = EffectMask & aurApp->GetEffectsToApply();
+                for (uint8 i = 0; i < spell->m_spellInfo->GetEffects().size(); ++i)
+                    if ((effMask & (1 << i)) && aurApp->HasEffect(i))
+                        effMask &= ~(1 << i);
+
+                _spellHitTarget->_ApplyAura(aurApp, effMask);
+            }
+        }
+
         // Needs to be called after dealing damage/healing to not remove breaking on damage auras
         spell->DoTriggersOnSpellHit(_spellHitTarget, EffectMask);
 
@@ -2733,7 +2748,7 @@ SpellMissInfo Spell::PreprocessSpellHit(Unit* unit, TargetInfo& hitInfo)
         else if (m_caster->IsFriendlyTo(unit))
         {
             // for delayed spells ignore negative spells (after duel end) for friendly targets
-            if (m_spellInfo->HasHitDelay() && unit->GetTypeId() == TYPEID_PLAYER && !IsPositive() && !m_caster->IsValidSpellAttackTarget(unit, m_spellInfo))
+            if (m_spellInfo->HasHitDelay() && unit->GetTypeId() == TYPEID_PLAYER && !IsPositive() && !m_caster->IsValidAssistTarget(unit, m_spellInfo))
                 return SPELL_MISS_EVADE;
 
             // assisting case, healing and resurrection
@@ -8170,13 +8185,13 @@ bool WorldObjectSpellTargetCheck::operator()(WorldObject* target) const
             case TARGET_CHECK_ENEMY:
                 if (unitTarget->IsTotem())
                     return false;
-                if (!_caster->IsValidAttackTarget(unitTarget, _spellInfo, false))
+                if (!_caster->IsValidAttackTarget(unitTarget, _spellInfo))
                     return false;
                 break;
             case TARGET_CHECK_ALLY:
                 if (unitTarget->IsTotem())
                     return false;
-                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo, false))
+                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo))
                     return false;
                 break;
             case TARGET_CHECK_PARTY:
@@ -8184,7 +8199,7 @@ bool WorldObjectSpellTargetCheck::operator()(WorldObject* target) const
                     return false;
                 if (unitTarget->IsTotem())
                     return false;
-                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo, false))
+                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo))
                     return false;
                 if (!refUnit->IsInPartyWith(unitTarget))
                     return false;
@@ -8200,7 +8215,7 @@ bool WorldObjectSpellTargetCheck::operator()(WorldObject* target) const
                     return false;
                 if (unitTarget->IsTotem())
                     return false;
-                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo, false))
+                if (!_caster->IsValidAssistTarget(unitTarget, _spellInfo))
                     return false;
                 if (!refUnit->IsInRaidWith(unitTarget))
                     return false;
@@ -8235,19 +8250,6 @@ bool WorldObjectSpellTargetCheck::operator()(WorldObject* target) const
             default:
                 break;
         }
-
-        // then check actual spell positivity to determine if the target is valid
-        // (negative spells may be targeted on allies)
-        if (_spellInfo->IsPositive())
-        {
-            if (!_caster->IsValidSpellAssistTarget(unitTarget, _spellInfo))
-                return false;
-        }
-        else
-        {
-            if (!_caster->IsValidSpellAttackTarget(unitTarget, _spellInfo))
-                return false;
-        }
     }
 
     if (!_condSrcInfo)