fixed graphhopper#242, Exception if speed is 0 but valid access flags and using shortest path algo.

Author: Peter

core/src/main/java/com/graphhopper/routing/Path.java

@@ -223,6 +223,9 @@ protected long calcMillis( double distance, long flags, boolean revert )
         if (Double.isInfinite(speed) || Double.isNaN(speed) || speed < 0)
             throw new IllegalStateException("Invalid speed stored in edge! " + speed);
 
+        if (speed == 0)
+            throw new IllegalStateException("Speed cannot be 0 for unblocked edge, use access properties to mark edge blocked! Should only occur for shortest path calculation. See #242.");
+
         return (long) (distance * 3600 / speed);
     }
 

core/src/test/java/com/graphhopper/routing/AbstractRoutingAlgorithmTester.java

@@ -87,7 +87,7 @@ public void testCalcFastestPath()
 
         Graph graphFastest = createGraph(false);
         initDirectedAndDiffSpeed(graphFastest);
-        Path p2 = createAlgo(graphFastest, 
+        Path p2 = createAlgo(graphFastest,
                 AlgorithmOptions.start().flagEncoder(carEncoder).weighting(new FastestWeighting(carEncoder)).build()).
                 calcPath(0, 3);
         assertEquals(Helper.createTList(0, 4, 6, 7, 5, 3), p2.calcNodes());
@@ -665,6 +665,26 @@ public void testTwoWeightsPerEdge()
         assertEquals(6568, p.getWeight(), 1);
     }
 
+    @Test
+    public void test0SpeedButUnblocked_Issue242()
+    {
+        Graph graph = createGraph(false);
+        long flags = carEncoder.setAccess(carEncoder.setSpeed(0, 0), true, true);
+
+        graph.edge(0, 1).setFlags(flags).setDistance(10);
+        graph.edge(1, 2).setFlags(flags).setDistance(10);
+
+        RoutingAlgorithm algo = createAlgo(graph);
+        try
+        {
+            Path p = algo.calcPath(0, 2);
+            assertTrue(false);
+        } catch (Exception ex)
+        {
+            assertTrue(ex.getMessage(), ex.getMessage().startsWith("Speed cannot be 0"));
+        }
+    }
+
     @Test
     public void testTwoWeightsPerEdge2()
     {