Core/Spells: corrected implementation of SPELL_AURA_BLOCK_SPELL_FAMILY and implement trigger cast flag to ignore blocked spells

src/server/game/Entities/Unit/Unit.h

@@ -327,7 +327,7 @@ enum TriggerCastFlags : uint32
     TRIGGERED_IGNORE_CASTER_AURASTATE               = 0x00000800,   //! Will ignore caster aura states including combat requirements and death state
     TRIGGERED_DISALLOW_PROC_EVENTS                  = 0x00001000,   //! Disallows proc events from triggered spell (default)
     TRIGGERED_IGNORE_CASTER_MOUNTED_OR_ON_VEHICLE   = 0x00002000,   //! Will ignore mounted/on vehicle restrictions
-    // reuse                                        = 0x00004000,
+    TRIGGERED_IGNORE_BLOCKED_SPELL_FAMILY           = 0x00004000,   //! Will ignore blocked casts of SPELL_AURA_BLOCK_SPELL_FAMILY
     // reuse                                        = 0x00008000,
     TRIGGERED_IGNORE_CASTER_AURAS                   = 0x00010000,   //! Will ignore caster aura restrictions or requirements
     TRIGGERED_DONT_RESET_PERIODIC_TIMER             = 0x00020000,   //! Will allow periodic aura timers to keep ticking (instead of resetting)

src/server/game/Spells/Spell.cpp

@@ -5360,10 +5360,10 @@ SpellCastResult Spell::CheckCast(bool strict, uint32* param1 /*= nullptr*/, uint
         }
     }
 
-    Unit::AuraEffectList const& blockSpells = m_caster->GetAuraEffectsByType(SPELL_AURA_BLOCK_SPELL_FAMILY);
-    for (Unit::AuraEffectList::const_iterator blockItr = blockSpells.begin(); blockItr != blockSpells.end(); ++blockItr)
-        if (uint32((*blockItr)->GetMiscValue()) == m_spellInfo->SpellFamilyName)
-            return SPELL_FAILED_SPELL_UNAVAILABLE;
+    if (!(_triggeredCastFlags & TRIGGERED_IGNORE_BLOCKED_SPELL_FAMILY))
+        for (AuraEffect const* blocked : m_caster->GetAuraEffectsByType(SPELL_AURA_BLOCK_SPELL_FAMILY))
+            if (!blocked->GetMiscValue() || uint32(blocked->GetMiscValue()) == m_spellInfo->SpellFamilyName)
+                return SPELL_FAILED_SPELL_UNAVAILABLE;
 
     bool reqCombat = true;
     Unit::AuraEffectList const& stateAuras = m_caster->GetAuraEffectsByType(SPELL_AURA_ABILITY_IGNORE_AURASTATE);