(svn r19269) -Codechange: PerformIndustryTileSlopeCheck() returns a succeeded or failed command.

3 files changed, 23 insertions, 10 deletions

diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index ec52c15b0..f4eee73e3 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -1349,7 +1349,9 @@ static CommandCost CheckIfIndustryTilesAreFree(TileIndex tile, const IndustryTil
 
 			if (HasBit(its->callback_mask, CBM_INDT_SHAPE_CHECK)) {
 				custom_shape = true;
-				if (!PerformIndustryTileSlopeCheck(tile, cur_tile, its, type, gfx, itspec_index)) return_cmd_error(_error_message);
+				CommandCost ret = PerformIndustryTileSlopeCheck(tile, cur_tile, its, type, gfx, itspec_index);
+				ret.SetGlobalErrorMessage();
+				if (ret.Failed()) return ret;
 			} else {
 				Slope tileh = GetTileSlope(cur_tile, NULL);
 				refused_slope |= IsSlopeRefused(tileh, its->slopes_refused);
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
index 63e8b7524..26905c004 100644
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -238,7 +238,16 @@ bool DrawNewIndustryTile(TileInfo *ti, Industry *i, IndustryGfx gfx, const Indus
 
 extern bool IsSlopeRefused(Slope current, Slope refused);
 
-bool PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile, const IndustryTileSpec *its, IndustryType type, IndustryGfx gfx, uint itspec_index)
+/** Check the slope of a tile of a new industry.
+ * @param ind_base_tile Base tile of the industry.
+ * @param ind_tile      Tile to check.
+ * @param its           Tile specification.
+ * @param type          Industry type.
+ * @param gfx           Gfx of the tile.
+ * @param itspec_index  Layout.
+ * @return Suceeded or failed command.
+ */
+CommandCost PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile, const IndustryTileSpec *its, IndustryType type, IndustryGfx gfx, uint itspec_index)
 {
 	Industry ind;
 	ind.index = INVALID_INDUSTRY;
@@ -248,12 +257,14 @@ bool PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile,
 
 	uint16 callback_res = GetIndustryTileCallback(CBID_INDTILE_SHAPE_CHECK, 0, itspec_index, gfx, &ind, ind_tile);
 	if (callback_res == CALLBACK_FAILED) {
-		return !IsSlopeRefused(GetTileSlope(ind_tile, NULL), its->slopes_refused);
+		if (!IsSlopeRefused(GetTileSlope(ind_tile, NULL), its->slopes_refused)) return CommandCost();
+		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
 	}
 	if (its->grf_prop.grffile->grf_version < 7) {
-		return callback_res != 0;
+		if (callback_res != 0) return CommandCost();
+		return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
 	}
-	if (callback_res == 0x400) return true;
+	if (callback_res == 0x400) return CommandCost();
 
 	/* Copy some parameters from the registers to the error message text ref. stack */
 	SwitchToErrorRefStack();
@@ -261,10 +272,10 @@ bool PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile,
 	SwitchToNormalRefStack();
 
 	switch (callback_res) {
-		case 0x401: _error_message = STR_ERROR_SITE_UNSUITABLE;                 return false;
-		case 0x402: _error_message = STR_ERROR_CAN_ONLY_BE_BUILT_IN_RAINFOREST; return false;
-		case 0x403: _error_message = STR_ERROR_CAN_ONLY_BE_BUILT_IN_DESERT;     return false;
-		default: _error_message = GetGRFStringID(its->grf_prop.grffile->grfid, 0xD000 + callback_res); return false;
+		case 0x401: return_cmd_error(STR_ERROR_SITE_UNSUITABLE);
+		case 0x402: return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_RAINFOREST);
+		case 0x403: return_cmd_error(STR_ERROR_CAN_ONLY_BE_BUILT_IN_DESERT);
+		default:    return_cmd_error(GetGRFStringID(its->grf_prop.grffile->grfid, 0xD000 + callback_res));
 	}
 }
 
diff --git a/src/newgrf_industrytiles.h b/src/newgrf_industrytiles.h
index 15751ff81..086e6b120 100644
--- a/src/newgrf_industrytiles.h
+++ b/src/newgrf_industrytiles.h
@@ -27,7 +27,7 @@ enum IndustryAnimationTrigger {
 
 bool DrawNewIndustryTile(TileInfo *ti, Industry *i, IndustryGfx gfx, const IndustryTileSpec *inds);
 uint16 GetIndustryTileCallback(CallbackID callback, uint32 param1, uint32 param2, IndustryGfx gfx_id, Industry *industry, TileIndex tile);
-bool PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile, const IndustryTileSpec *its, IndustryType type, IndustryGfx gfx, uint itspec_index);
+CommandCost PerformIndustryTileSlopeCheck(TileIndex ind_base_tile, TileIndex ind_tile, const IndustryTileSpec *its, IndustryType type, IndustryGfx gfx, uint itspec_index);
 
 void AnimateNewIndustryTile(TileIndex tile);
 bool StartStopIndustryTileAnimation(TileIndex tile, IndustryAnimationTrigger iat, uint32 random = Random());