Core/Spells: Added partial support for Mixology (duration boost)

Update issue #4097.
Status: Confirmed
Implemented duration part, waiting for the rest

--HG--
branch : trunk

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

@@ -12763,9 +12763,24 @@ int32 Unit::ModSpellDuration(SpellEntry const* spellProto, Unit const* target, i
         if (durationMod != 0)
             duration = int32(float(duration) * float(100.0f+durationMod) / 100.0f);
     }
+    else
+    {
         //else positive mods here, there are no currently
         //when there will be, change GetTotalAuraModifierByMiscValue to GetTotalPositiveAuraModifierByMiscValue
 
+        // Mixology - duration boost
+        if (target->GetTypeId() == TYPEID_PLAYER)
+        {
+            if (spellProto->SpellFamilyName == SPELLFAMILY_POTION && (
+                sSpellMgr.IsSpellMemberOfSpellGroup(spellProto->Id, SPELL_GROUP_ELIXIR_BATTLE) ||
+                sSpellMgr.IsSpellMemberOfSpellGroup(spellProto->Id, SPELL_GROUP_ELIXIR_GUARDIAN)))
+            {
+                if (target->HasAura(53042) && target->HasSpell(spellProto->EffectTriggerSpell[0]))
+                    duration *= 2;
+            }
+        }
+    }
+
     // Glyphs which increase duration of selfcasted buffs
     if (target == this)
     {