(svn r25839) -Codechange: Use NUM_HOUSES_PER_GRF instead of NUM_HOUSES to properly distinguish limits per NewGRF and limits of the pool.

-Change: [NewGRF] Lower the limit of house 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.

2 files changed, 12 insertions, 10 deletions

diff --git a/src/house.h b/src/house.h
index b74e13c18..ddc2a448c 100644
--- a/src/house.h
+++ b/src/house.h
@@ -24,9 +24,11 @@
  */
 static const byte TOWN_HOUSE_COMPLETED = 3;
 
+static const HouseID NUM_HOUSES_PER_GRF = 255;    ///< Number of supported houses per NewGRF; limited to 255 to allow extending Action3 with an extended byte later on.
+
 static const uint HOUSE_NO_CLASS      = 0;
-static const HouseID NEW_HOUSE_OFFSET = 110;
-static const HouseID NUM_HOUSES       = 512;
+static const HouseID NEW_HOUSE_OFFSET = 110;    ///< Offset for new houses.
+static const HouseID NUM_HOUSES       = 512;    ///< Total number of houses.
 static const HouseID INVALID_HOUSE_ID = 0xFFFF;
 
 /**
diff --git a/src/newgrf.cpp b/src/newgrf.cpp
index 78c662ad4..8274dd8b9 100644
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -2183,14 +2183,14 @@ static ChangeInfoResult TownHouseChangeInfo(uint hid, int numinfo, int prop, Byt
 {
 	ChangeInfoResult ret = CIR_SUCCESS;
 
-	if (hid + numinfo > NUM_HOUSES) {
-		grfmsg(1, "TownHouseChangeInfo: Too many houses loaded (%u), max (%u). Ignoring.", hid + numinfo, NUM_HOUSES);
+	if (hid + numinfo > NUM_HOUSES_PER_GRF) {
+		grfmsg(1, "TownHouseChangeInfo: Too many houses loaded (%u), max (%u). Ignoring.", hid + numinfo, NUM_HOUSES_PER_GRF);
 		return CIR_INVALID_ID;
 	}
 
 	/* Allocate house specs if they haven't been allocated already. */
 	if (_cur.grffile->housespec == NULL) {
-		_cur.grffile->housespec = CallocT<HouseSpec*>(NUM_HOUSES);
+		_cur.grffile->housespec = CallocT<HouseSpec*>(NUM_HOUSES_PER_GRF);
 	}
 
 	for (int i = 0; i < numinfo; i++) {
@@ -7789,7 +7789,7 @@ static void ResetCustomHouses()
 	for (GRFFile **file = _grf_files.Begin(); file != end; file++) {
 		HouseSpec **&housespec = (*file)->housespec;
 		if (housespec == NULL) continue;
-		for (uint i = 0; i < NUM_HOUSES; i++) {
+		for (uint i = 0; i < NUM_HOUSES_PER_GRF; i++) {
 			free(housespec[i]);
 		}
 
@@ -8419,14 +8419,14 @@ static void FinaliseHouseArray()
 		HouseSpec **&housespec = (*file)->housespec;
 		if (housespec == NULL) continue;
 
-		for (int i = 0; i < NUM_HOUSES; i++) {
+		for (int i = 0; i < NUM_HOUSES_PER_GRF; i++) {
 			HouseSpec *hs = housespec[i];
 
 			if (hs == NULL) continue;
 
-			const HouseSpec *next1 = (i + 1 < NUM_HOUSES ? housespec[i + 1] : NULL);
-			const HouseSpec *next2 = (i + 2 < NUM_HOUSES ? housespec[i + 2] : NULL);
-			const HouseSpec *next3 = (i + 3 < NUM_HOUSES ? housespec[i + 3] : NULL);
+			const HouseSpec *next1 = (i + 1 < NUM_HOUSES_PER_GRF ? housespec[i + 1] : NULL);
+			const HouseSpec *next2 = (i + 2 < NUM_HOUSES_PER_GRF ? housespec[i + 2] : NULL);
+			const HouseSpec *next3 = (i + 3 < NUM_HOUSES_PER_GRF ? housespec[i + 3] : NULL);
 
 			if (!IsHouseSpecValid(hs, next1, next2, next3, (*file)->filename)) continue;