From 1a562948a67128b8931c9d034fb151d5c439ab29 Mon Sep 17 00:00:00 2001
From: Skjalf <47818697+Nyeriah@users.noreply.github.com>
Date: Mon, 20 Mar 2023 13:16:58 -0300
Subject: [PATCH] =?UTF-8?q?fix(Core/Object):=20Permanently=20invisible=20c?=
 =?UTF-8?q?reatures=20should=20be=20able=20to=20e=E2=80=A6=20(#15498)?=
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---
 src/server/game/Entities/Object/Object.cpp | 35 ++++++++++++++++++----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/server/game/Entities/Object/Object.cpp b/src/server/game/Entities/Object/Object.cpp
index 7d8f75a61..a4b218b36 100644
--- a/src/server/game/Entities/Object/Object.cpp
+++ b/src/server/game/Entities/Object/Object.cpp
@@ -1863,7 +1863,9 @@ bool WorldObject::CanSeeOrDetect(WorldObject const* obj, bool ignoreStealth, boo
             return false;
 
     if (!CanDetect(obj, ignoreStealth, !distanceCheck, checkAlert))
+    {
         return false;
+    }
 
     return true;
 }
@@ -1890,7 +1892,9 @@ bool WorldObject::CanDetect(WorldObject const* obj, bool ignoreStealth, bool che
     if (!ignoreStealth)
     {
         if (!seer->CanDetectInvisibilityOf(obj)) // xinef: added ignoreStealth, allow AoE spells to hit invisible targets!
+        {
             return false;
+        }
 
         if (!seer->CanDetectStealthOf(obj, checkAlert))
         {
@@ -1923,11 +1927,32 @@ bool WorldObject::CanDetectInvisibilityOf(WorldObject const* obj) const
     // It seems like that only Units are affected by this check (couldn't see arena doors with preparation invisibility)
     if (obj->ToUnit())
     {
-        uint32 objMask = m_invisibility.GetFlags() & obj->m_invisibilityDetect.GetFlags();
-        // xinef: include invisible flags of caster in the mask, 2 invisible objects should be able to detect eachother
-        objMask |= m_invisibility.GetFlags() & obj->m_invisibility.GetFlags();
-        if (objMask != m_invisibility.GetFlags())
-            return false;
+        // Permanently invisible creatures should be able to engage non-invisible targets.
+        // ex. Skulking Witch (20882) / Greater Invisibility (16380)
+        bool isPermInvisibleCreature = false;
+        if (Creature const* baseObj = ToCreature())
+        {
+            auto auraEffects = baseObj->GetAuraEffectsByType(SPELL_AURA_MOD_INVISIBILITY);
+            for (auto const effect : auraEffects)
+            {
+                if (SpellInfo const* spell = effect->GetSpellInfo())
+                {
+                    if (spell->GetMaxDuration() == -1)
+                    {
+                        isPermInvisibleCreature = true;
+                    }
+                }
+            }
+        }
+
+        if (!isPermInvisibleCreature)
+        {
+            uint32 objMask = m_invisibility.GetFlags() & obj->m_invisibilityDetect.GetFlags();
+            // xinef: include invisible flags of caster in the mask, 2 invisible objects should be able to detect eachother
+            objMask |= m_invisibility.GetFlags() & obj->m_invisibility.GetFlags();
+            if (objMask != m_invisibility.GetFlags())
+                return false;
+        }
     }
 
     for (uint32 i = 0; i < TOTAL_INVISIBILITY_TYPES; ++i)