bugfix(aigroup): Prevent game crash when a player is selected in Replay playback.

Author: Caball009

Core/GameEngine/Source/GameLogic/System/GameLogicDispatch.cpp

@@ -2120,10 +2120,9 @@ void GameLogic::logicMessageDispatcher( GameMessage *msg, void *userData )
 	}
 
 #if RETAIL_COMPATIBLE_AIGROUP
-	// TheSuperHackers @bugfix xezon 28/06/2025 This hack avoids crashing when players are selected during Replay playback.
-	// It can read data from an already deleted AIGroup and return this function when its member size is 0, signifying that
-	// it is indeed deleted.
-	if (currentlySelectedGroup && currentlySelectedGroup->getCount() == 0)
+	// TheSuperHackers @bugfix xezon/Caball009 14/05/2026 This hack avoids crashing when players are selected during Replay playback.
+	// The current AI group may have been destroyed, and its memory deallocated, in which case it shouldn't be used.
+	if (currentlySelectedGroup && !TheAI->doesGroupExist(currentlySelectedGroup))
 		return;
 #endif
 

GeneralsMD/Code/GameEngine/Include/GameLogic/AI.h

@@ -279,6 +279,7 @@ class AI : public SubsystemInterface, public Snapshot
 	AIGroupPtr createGroup(); ///< instantiate a new AI Group
 	void destroyGroup( AIGroup *group );	///< destroy the given AI Group
 	AIGroup *findGroup( UnsignedInt id );	///< return the AI Group with the given ID
+	Bool doesGroupExist(AIGroup* group); ///< return whether the given AI Group exists, i.e. is part of the group list
 
 	// Formation info
 	enum FormationID getNextFormationID();

GeneralsMD/Code/GameEngine/Source/GameLogic/AI/AI.cpp

@@ -497,6 +497,11 @@ AIGroup *AI::findGroup( UnsignedInt id )
 	return nullptr;
 }
 
+Bool AI::doesGroupExist(AIGroup* group)
+{
+	return std::find(m_groupList.begin(), m_groupList.end(), group) != m_groupList.end();
+}
+
 //--------------------------------------------------------------------------------------------------------
 /**
  * Get the next formation id.