Fix fallback speed validity checks (#5300)

* fix fallback_speeds check to only accept values > 0

* add invalid_fallback_speed

include/engine/api/table_parameters.hpp

@@ -59,7 +59,7 @@ struct TableParameters : public BaseParameters
 {
     std::vector<std::size_t> sources;
     std::vector<std::size_t> destinations;
-    double fallback_speed = 0;
+    double fallback_speed = INVALID_FALLBACK_SPEED;
 
     enum class FallbackCoordinateType
     {
@@ -137,7 +137,7 @@ struct TableParameters : public BaseParameters
         if (std::any_of(begin(destinations), end(destinations), not_in_range))
             return false;
 
-        if (fallback_speed < 0)
+        if (fallback_speed <= 0)
             return false;
 
         if (scale_factor <= 0)

include/nodejs/node_osrm_support.hpp

@@ -1192,7 +1192,7 @@ argumentsToTableParameter(const Nan::FunctionCallbackInfo<v8::Value> &args,
             Nan::ThrowError("fallback_speed must be a number");
             return table_parameters_ptr();
         }
-        else if (fallback_speed->NumberValue() < 0)
+        else if (fallback_speed->NumberValue() <= 0)
         {
             Nan::ThrowError("fallback_speed must be > 0");
             return table_parameters_ptr();

include/util/typedefs.hpp

@@ -116,6 +116,7 @@ static const EdgeDuration MAXIMAL_EDGE_DURATION = std::numeric_limits<EdgeDurati
 static const EdgeDistance MAXIMAL_EDGE_DISTANCE = std::numeric_limits<EdgeDistance>::max();
 static const TurnPenalty INVALID_TURN_PENALTY = std::numeric_limits<TurnPenalty>::max();
 static const EdgeDistance INVALID_EDGE_DISTANCE = std::numeric_limits<EdgeDistance>::max();
+static const EdgeDistance INVALID_FALLBACK_SPEED = std::numeric_limits<double>::max();
 
 // FIXME the bitfields we use require a reduced maximal duration, this should be kept consistent
 // within the code base. For now we have to ensure that we don't case 30 bit to -1 and break any