Make astarInner an `int` and ASSERT that it stays non-negative (i.e. that it doesn't overflow)

git-svn-id: svn+ssh://svn.gna.org/svn/warzone/trunk@4725 4a71c877-e1ca-e34f-864e-861f7616d084

src/astar.c

@@ -41,7 +41,7 @@ static SDWORD	astarOuter, astarRemove;
  *
  *  @ingroup pathfinding
  */
-SDWORD	astarInner;
+int astarInner = 0;
 
 // The structure to store a node of the route
 typedef struct _fp_node
@@ -450,6 +450,8 @@ static 	FP_NODE		*psNearest, *psRoute;
 			}
 
 			astarInner += 1;
+			ASSERT(astarInner >= 0, "astarInner overflowed!");
+
 
 			// Now insert the point into the appropriate list
 			if (!psFound)

src/astar.h

@@ -51,9 +51,11 @@ typedef struct _astar_route
 } ASTAR_ROUTE;
 
 // counters for a-star
-extern SDWORD astarInner;
+extern int astarInner;
 
 /** Reset the A* counters
+ *
+ *  This function resets astarInner among others.
  *
  *  @ingroup pathfinding
  */

src/fpath.c

@@ -694,6 +694,8 @@ FPATH_RETVAL fpathRoute(DROID* psDroid, MOVE_CONTROL *psMoveCntl,
 			fpathBlockingTile == fpathLiftBlockingTile,
 			"fpathRoute: invalid blocking function" );
 
+	ASSERT(astarInner >= 0, "astarInner overflowed!");
+
 	if (astarInner > FPATH_LOOP_LIMIT)
 	{
 		// Time out