Add possibility to ignore instant spells when checking if a spell is currently being casted. Fixes issue #2227

--HG--
branch : trunk

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

@@ -3535,11 +3535,15 @@ void Unit::FinishSpell(CurrentSpellTypes spellType, bool ok /*= true*/)
     spell->finish(ok);
 }
 
-bool Unit::IsNonMeleeSpellCasted(bool withDelayed, bool skipChanneled, bool skipAutorepeat, bool isAutoshoot) const
+bool Unit::IsNonMeleeSpellCasted(bool withDelayed, bool skipChanneled, bool skipAutorepeat, bool isAutoshoot, bool checkInstant) const
 {
     // We don't do loop here to explicitly show that melee spell is excluded.
     // Maybe later some special spells will be excluded too.
 
+    // if checkInstant then instant spells shouldn't count as being casted
+    if (checkInstant && m_currentSpells[CURRENT_GENERIC_SPELL] && !m_currentSpells[CURRENT_GENERIC_SPELL]->GetCastTime())
+        return false;
+
     // generic spells are casted when they are not finished and not delayed
     if (m_currentSpells[CURRENT_GENERIC_SPELL] &&
         (m_currentSpells[CURRENT_GENERIC_SPELL]->getState() != SPELL_STATE_FINISHED) &&