Fix PathDetails exception for empty EdgeIdDs list (graphhopper#1240)

* Ignore the tests, reverted memory and some minor improvements

* Revert IntelliJ formatting issue

* Removed pointList.isEmpty

Author: boldtrn

core/src/main/java/com/graphhopper/PathWrapper.java

@@ -254,9 +254,6 @@ public void addPathDetails(Map<String, List<PathDetail>> details) {
             throw new IllegalStateException("Details have to be the same size");
         }
         for (Map.Entry<String, List<PathDetail>> detailEntry : details.entrySet()) {
-            if (detailEntry.getValue().isEmpty())
-                throw new IllegalStateException("PathDetails " + detailEntry.getKey() + " must not be empty");
-
             if (this.pathDetails.containsKey(detailEntry.getKey())) {
                 List<PathDetail> pd = this.pathDetails.get(detailEntry.getKey());
                 PathMerger.merge(pd, detailEntry.getValue());

core/src/main/java/com/graphhopper/util/PathSimplification.java

@@ -49,7 +49,8 @@ public PathSimplification(PathWrapper pathWrapper, DouglasPeucker douglasPeucker
         this.pathDetails = pathWrapper.getPathDetails();
         for (String name : pathDetails.keySet()) {
             List<PathDetail> pathDetailList = pathDetails.get(name);
-            if (pathDetailList.isEmpty())
+            // If the pointList only contains one point, PathDetails have to be empty because 1 point => 0 edges
+            if (pathDetailList.isEmpty() && pointList.size() > 1)
                 throw new IllegalStateException("PathDetails " + name + " must not be empty");
 
             listsToSimplify.add(pathDetailList);
@@ -58,7 +59,7 @@ public PathSimplification(PathWrapper pathWrapper, DouglasPeucker douglasPeucker
     }
 
     public PointList simplify() {
-        if (listsToSimplify.isEmpty() || pointList.isEmpty())
+        if (listsToSimplify.isEmpty() || pointList.size() <= 2)
             return pointList;
 
         // The offset of already included points

reader-osm/src/test/java/com/graphhopper/GraphHopperIT.java

@@ -730,7 +730,7 @@ public void testCircularJunctionInstructionsWithCH() {
 
         assertEquals(2, tmpHopper.getCHFactoryDecorator().getPreparations().size());
 
-        GHResponse rsp = tmpHopper.route(new GHRequest(52.513505,13.350443, 52.513505,13.350245)
+        GHResponse rsp = tmpHopper.route(new GHRequest(52.513505, 13.350443, 52.513505, 13.350245)
                 .setVehicle(tmpVehicle).setWeighting(tmpWeightCalcStr));
 
         Instruction instr = rsp.getBest().getInstructions().get(1);
@@ -870,6 +870,26 @@ public void testPathDetails1216() {
         assertFalse(rsp.hasErrors());
     }
 
+    @Test
+    public void testPathDetailsSamePoint() {
+        GraphHopper tmpHopper = new GraphHopperOSM().
+                setOSMFile(DIR + "/north-bayreuth.osm.gz").
+                setCHEnabled(false).
+                setGraphHopperLocation(tmpGraphFile).
+                setEncodingManager(new EncodingManager("car"));
+        tmpHopper.importOrLoad();
+
+        GHRequest req = new GHRequest().
+                addPoint(new GHPoint(49.984352, 11.498802)).
+                addPoint(new GHPoint(49.984352, 11.498802)).
+                setVehicle("car").setWeighting("fastest").
+                setPathDetails(Arrays.asList(Parameters.DETAILS.AVERAGE_SPEED));
+
+        GHResponse rsp = tmpHopper.route(req);
+
+        assertFalse(rsp.hasErrors());
+    }
+
     @Test
     public void testFlexMode_631() {
         String tmpOsmFile = DIR + "/monaco.osm.gz";

web/src/test/java/com/graphhopper/http/GraphHopperServletIT.java

@@ -179,6 +179,17 @@ public void testPathDetails() throws Exception {
         assertEquals(expectedTime, actualTime);
     }
 
+    @Test
+    public void testPathDetailsSamePoint() throws Exception {
+        GraphHopperAPI hopper = new com.graphhopper.api.GraphHopperWeb();
+        assertTrue(hopper.load(getTestRouteAPIUrl()));
+        GHRequest request = new GHRequest(42.554851, 1.536198, 42.554851, 1.536198);
+        request.setPathDetails(Arrays.asList("average_speed", "edge_id", "time"));
+        GHResponse rsp = hopper.route(request);
+        assertFalse(rsp.getErrors().toString(), rsp.hasErrors());
+        assertTrue(rsp.getErrors().toString(), rsp.getErrors().isEmpty());
+    }
+
     @Test
     public void testPathDetailsNoConnection() throws Exception {
         GraphHopperAPI hopper = new com.graphhopper.api.GraphHopperWeb();