bugfix(pathfinder): Fix various crashes in Pathfinder due to inadequate cleanup of pathfinding resources (#994)

Co-authored-by: Bart Roossien <roossienb@users.noreply.github.com>

Author: Mauller

Core/GameEngine/Include/Common/GameDefines.h

@@ -35,6 +35,13 @@
 #define RETAIL_COMPATIBLE_XFER_SAVE (1) // Game is expected to be Xfer Save compatible with retail Generals 1.08, Zero Hour 1.04
 #endif
 
+// This is here to easily toggle between the retail compatible with fixed pathfinding fallback and pure fixed pathfinding mode
+#if RETAIL_COMPATIBLE_CRC
+#define RETAIL_COMPATIBLE_PATHFINDING (1)
+#else
+#define RETAIL_COMPATIBLE_PATHFINDING (0)
+#endif
+
 // This is essentially synonymous for RETAIL_COMPATIBLE_CRC. There is a lot wrong with AIGroup, such as use-after-free, double-free, leaks,
 // but we cannot touch it much without breaking retail compatibility. Do not shy away from using massive hacks when fixing issues with AIGroup,
 // but put them behind this macro.

Generals/Code/GameEngine/Include/GameLogic/AIPathfind.h

@@ -207,6 +207,9 @@ class PathfindCellInfo
 {
 	friend class PathfindCell;
 public:
+#if RETAIL_COMPATIBLE_PATHFINDING
+	static void forceCleanPathFindCellInfos(void);
+#endif
 	static void allocateCellInfos(void);
 	static void releaseCellInfos(void);
 
@@ -691,6 +694,9 @@ class Pathfinder : PathfindServicesInterface, public Snapshot
 	Path *getDebugPath( void );
 	void setDebugPath( Path *debugpath );
 
+#if RETAIL_COMPATIBLE_PATHFINDING
+	void forceCleanCells(void);
+#endif
 	void cleanOpenAndClosedLists(void);
 
 	// Adjusts the destination to a spot near dest that is not occupied by other units.