(svn r25834) -Codechange: Use NUM_OBJECTS_PER_GRF instead of NUM_OBJECTS to properly distinguish limits per NewGRF and limits of the pool.

-Change: [NewGRF] Lower the limit of object types per NewGRF from 256 to 255 to prevent usage of ID 0xFF in Action3, and thus allowing it to become an extended byte somewhen.

src/newgrf.cpp

@@ -3773,14 +3773,14 @@ static ChangeInfoResult ObjectChangeInfo(uint id, int numinfo, int prop, ByteRea
 {
 	ChangeInfoResult ret = CIR_SUCCESS;
 
-	if (id + numinfo > NUM_OBJECTS) {
-		grfmsg(1, "ObjectChangeInfo: Too many objects loaded (%u), max (%u). Ignoring.", id + numinfo, NUM_OBJECTS);
+	if (id + numinfo > NUM_OBJECTS_PER_GRF) {
+		grfmsg(1, "ObjectChangeInfo: Too many objects loaded (%u), max (%u). Ignoring.", id + numinfo, NUM_OBJECTS_PER_GRF);
 		return CIR_INVALID_ID;
 	}
 
 	/* Allocate object specs if they haven't been allocated already. */
 	if (_cur.grffile->objectspec == NULL) {
-		_cur.grffile->objectspec = CallocT<ObjectSpec*>(NUM_OBJECTS);
+		_cur.grffile->objectspec = CallocT<ObjectSpec*>(NUM_OBJECTS_PER_GRF);
 	}
 
 	for (int i = 0; i < numinfo; i++) {
@@ -7882,7 +7882,7 @@ static void ResetCustomObjects()
 	for (GRFFile **file = _grf_files.Begin(); file != end; file++) {
 		ObjectSpec **&objectspec = (*file)->objectspec;
 		if (objectspec == NULL) continue;
-		for (uint i = 0; i < NUM_OBJECTS; i++) {
+		for (uint i = 0; i < NUM_OBJECTS_PER_GRF; i++) {
 			free(objectspec[i]);
 		}
 
@@ -8552,7 +8552,7 @@ static void FinaliseObjectsArray()
 	for (GRFFile **file = _grf_files.Begin(); file != end; file++) {
 		ObjectSpec **&objectspec = (*file)->objectspec;
 		if (objectspec != NULL) {
-			for (int i = 0; i < NUM_OBJECTS; i++) {
+			for (int i = 0; i < NUM_OBJECTS_PER_GRF; i++) {
 				if (objectspec[i] != NULL && objectspec[i]->grf_prop.grffile != NULL && objectspec[i]->enabled) {
 					_object_mngr.SetEntitySpec(objectspec[i]);
 				}

src/object_type.h

@@ -21,8 +21,10 @@ static const ObjectType OBJECT_STATUE       =   2;    ///< Statue in towns
 static const ObjectType OBJECT_OWNED_LAND   =   3;    ///< Owned land 'flag'
 static const ObjectType OBJECT_HQ           =   4;    ///< HeadQuarter of a player
 
+static const ObjectType NUM_OBJECTS_PER_GRF = 255;    ///< Number of supported objects per NewGRF; limited to 255 to allow extending Action3 with an extended byte later on.
+
 static const ObjectType NEW_OBJECT_OFFSET   =   5;    ///< Offset for new objects
-static const ObjectType NUM_OBJECTS         = 256;    ///< Number of supported objects
+static const ObjectType NUM_OBJECTS         = 256;    ///< Number of supported objects overall
 static const ObjectType INVALID_OBJECT_TYPE = 0xFFFF; ///< An invalid object
 
 /** Unique identifier for an object. */