Tryfixing secure UI frames broken on reconnecting in combat

This is an important UI QoL fix mostly aimed at 2.0.0+ clients to ensure secure UI elements created/initialized properly when reconnecting in combat.

1.12.x is not affected as much by this due to less restrictive UI API.

src/game/Entities/CharacterHandler.cpp

@@ -1101,6 +1101,9 @@ void WorldSession::HandlePlayerLogin(LoginQueryHolder* holder)
 
 void WorldSession::HandlePlayerReconnect()
 {
+    // Detect if reconnecting in combat
+    const bool inCombat = _player->IsInCombat();
+
     // stop logout timer if need
     LogoutRequest(0);
 
@@ -1240,6 +1243,10 @@ void WorldSession::HandlePlayerReconnect()
     // Undo flags and states set by logout if present:
     _player->SetStunnedByLogout(false);
 
+    // Mark self for unit flags update to ensure re-application of combat flag at own client
+    if (inCombat)
+        _player->ForceValuesUpdateAtIndex(UNIT_FIELD_FLAGS);
+
     m_playerLoading = false;
 }
 

src/game/Entities/Object.cpp

@@ -670,6 +670,13 @@ void Object::BuildValuesUpdate(uint8 updatetype, ByteBuffer* data, UpdateMask* u
                                     value &= ~UNIT_FLAG_TAXI_FLIGHT;
                     }
 
+                    // On login/reconnect: delay combat state application at client UI to not interfere with secure frames init
+                    if (target == this && (value & UNIT_FLAG_IN_COMBAT))
+                    {
+                        if (static_cast<Player const*>(this)->GetSession()->PlayerLoading())
+                            value &= ~UNIT_FLAG_IN_COMBAT;
+                    }
+
                     *data << value;
                 }
                 // Hide special-info for non empathy-casters,