Merge branch 'save_ext' into enhanced_viewport_overlay-sx

src/vehicle.cpp

@@ -1347,6 +1347,9 @@ void AgeVehicle(Vehicle *v)
  * @param front The front vehicle of the consist to check.
  * @param colour The string to show depending on if we are unloading or loading
  * @return A percentage of how full the Vehicle is.
+ *         Percentages are rounded towards 50%, so that 0% and 100% are only returned
+ *         if the vehicle is completely empty or full.
+ *         This is useful for both display and conditional orders.
  */
 uint8 CalcPercentVehicleFilled(const Vehicle *front, StringID *colour)
 {
@@ -1394,7 +1397,13 @@ uint8 CalcPercentVehicleFilled(const Vehicle *front, StringID *colour)
 	if (max == 0) return 100;
 
 	/* Return the percentage */
-	return (count * 100) / max;
+	if (count * 2 < max) {
+		/* Less than 50%; round up, so that 0% means really empty. */
+		return CeilDiv(count * 100, max);
+	} else {
+		/* More than 50%; round down, so that 100% means really full. */
+		return (count * 100) / max;
+	}
 }
 
 /**