(svn r21916) -Fix [FS#4442]: the minimum speed needed for (realistic) acceleration to work properly can sometimes be more than the (temporary) maximum speed causing Clamp to "fail". Make sure that the minimum speed always overrules the maximum speed

1 files changed, 6 insertions, 1 deletions

diff --git a/src/ground_vehicle.hpp b/src/ground_vehicle.hpp
index 65bcb7653..a4be384a6 100644
--- a/src/ground_vehicle.hpp
+++ b/src/ground_vehicle.hpp
@@ -404,7 +404,12 @@ protected:
 			tempmax = max(this->cur_speed - (this->cur_speed / 10) - 1, max_speed);
 		}
 
-		this->cur_speed = spd = Clamp(this->cur_speed + ((int)spd >> 8), min_speed, tempmax);
+		/* Enforce a maximum and minimum speed. Normally we would use something like
+		 * Clamp for this, but in this case min_speed might be below the maximum speed
+		 * threshold for some reason. That makes acceleration fail and assertions
+		 * happen in Clamp. So make it explicit that min_speed overrules the maximum
+		 * speed by explicit ordering of min and max. */
+		this->cur_speed = spd = max(min(this->cur_speed + ((int)spd >> 8), tempmax), min_speed);
 
 		int scaled_spd = this->GetAdvanceSpeed(spd);