Merge pull request #2762 from Kapoeira/master

Core/Spells: Prevent deterrance from parrying spells that require the attacker to be behind the hunter, like Shred or Ambush.

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

@@ -2402,7 +2402,9 @@ SpellMissInfo Unit::MeleeSpellHitResult(Unit* victim, SpellInfo const* spell)
     }
 
     // Check for attack from behind
-    if (!victim->HasInArc(M_PI, this) && !victim->HasAuraType(SPELL_AURA_IGNORE_HIT_DIRECTION))
+    if (!victim->HasInArc(M_PI, this))
+    {
+        if (!victim->HasAuraType(SPELL_AURA_IGNORE_HIT_DIRECTION))
         {
             // Can`t dodge from behind in PvP (but its possible in PvE)
             if (victim->GetTypeId() == TYPEID_PLAYER)
@@ -2411,6 +2413,12 @@ SpellMissInfo Unit::MeleeSpellHitResult(Unit* victim, SpellInfo const* spell)
             canParry = false;
             canBlock = false;
         }
+        else // Only deterrence as of 3.3.5
+        {
+            if (spell->AttributesCu & SPELL_ATTR0_CU_REQ_CASTER_BEHIND_TARGET)
+                canParry = false;
+        }
+    }
     // Check creatures flags_extra for disable parry
     if (victim->GetTypeId() == TYPEID_UNIT)
     {