(svn r10980) -Fix [FS#1158] : This will hopefully fix the case of an assert that happens when an industry uses a special gfx index (tile spec 0xFF). This 0xFF is the sentinel of a special check done for oil rigs, where water need to be around, but no tile will be constructed on it.

Problem is that the upper limit of gfx tiles is currently at 175.  So, of course the system will assert with 255 ;)

src/industry.h

@@ -222,9 +222,18 @@ extern IndustryTileSpec _industry_tile_specs[NUM_INDUSTRYTILES];
 
 static inline IndustryGfx GetTranslatedIndustryTileID(IndustryGfx gfx)
 {
-	assert(gfx < INVALID_INDUSTRYTILE);
-	const IndustryTileSpec *it = &_industry_tile_specs[gfx];
-	return it->grf_prop.override == INVALID_INDUSTRYTILE ? gfx : it->grf_prop.override;
+	/* the 0xFF should be GFX_WATERTILE_SPECIALCHECK but for reasons of include mess,
+	 * we'll simplify the writing.
+	 * Basically, the first test is required since the GFX_WATERTILE_SPECIALCHECK value
+	 * will never be assigned as a tile index and is only required in order to do some
+	 * tests while building the industry (as in WATER REQUIRED */
+	if (gfx != 0xFF) {
+		assert(gfx < INVALID_INDUSTRYTILE);
+		const IndustryTileSpec *it = &_industry_tile_specs[gfx];
+		return it->grf_prop.override == INVALID_INDUSTRYTILE ? gfx : it->grf_prop.override;
+	} else {
+		return gfx;
+	}
 }
 
 /* smallmap_gui.cpp */

src/industry_cmd.cpp

@@ -1183,11 +1183,11 @@ static bool CheckIfIndustryTilesAreFree(TileIndex tile, const IndustryTileTable
 		TileIndex cur_tile = tile + ToTileIndexDiff(it->ti);
 
 		if (!IsValidTile(cur_tile)) {
-			if (gfx == 0xff) continue;
+			if (gfx == GFX_WATERTILE_SPECIALCHECK) continue;
 			return false;
 		}
 
-		if (gfx == 0xFF) {
+		if (gfx == GFX_WATERTILE_SPECIALCHECK) {
 			if (!IsTileType(cur_tile, MP_WATER) ||
 					GetTileSlope(cur_tile, NULL) != SLOPE_FLAT) {
 				return false;
@@ -1452,7 +1452,7 @@ static void DoCreateNewIndustry(Industry *i, TileIndex tile, int type, const Ind
 	do {
 		TileIndex cur_tile = tile + ToTileIndexDiff(it->ti);
 
-		if (it->gfx != 0xFF) {
+		if (it->gfx != GFX_WATERTILE_SPECIALCHECK) {
 			byte size;
 
 			size = it->ti.x;

src/industry_map.h

@@ -48,6 +48,7 @@ enum {
 	GFX_BUBBLE_CATCHER                 = 162,
 	GFX_TOFFEE_QUARY                   = 165,
 	GFX_SUGAR_MINE_SIEVE               = 174,
+	GFX_WATERTILE_SPECIALCHECK         = 255,  ///< not really a tile, but rather a very special check
 };
 
 /**