(svn r4640) - Add: IsValidDiagDirection, IsValidDirection and IsValidAxis functions.

 - Codechange: Use IsValidDiagDirection() in CmdBuildRoadStop().

2 files changed, 18 insertions, 2 deletions

diff --git a/direction.h b/direction.h
index c7a8498f6..ba3213896 100644
--- a/direction.h
+++ b/direction.h
@@ -93,7 +93,8 @@ static inline Direction DiagDirToDir(DiagDirection dir)
 /* the 2 axis */
 typedef enum Axis {
 	AXIS_X = 0,
-	AXIS_Y = 1
+	AXIS_Y = 1,
+	AXIS_END
 } Axis;
 
 
@@ -112,4 +113,19 @@ static inline DiagDirection AxisToDiagDir(Axis a)
 	return (DiagDirection)(2 - a);
 }
 
+static inline bool IsValidDiagDirection(DiagDirection d)
+{
+	return d < DIAGDIR_END;
+}
+
+static inline bool IsValidDirection(DiagDirection d)
+{
+	return d < DIR_END;
+}
+
+static inline bool IsValidAxis(DiagDirection d)
+{
+	return d < AXIS_END;
+}
+
 #endif
diff --git a/station_cmd.c b/station_cmd.c
index e7fcb9ca2..491454573 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -1360,7 +1360,7 @@ int32 CmdBuildRoadStop(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	bool type = !!p2;
 
 	/* Saveguard the parameters */
-	if (p1 > 3) return CMD_ERROR;
+	if (!IsValidDiagDirection(p1)) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);