Attach the dangling path polygon remainder to the last path section

This can happen on longer paths with distance-based splitting due to
accumulating errors, which then would results in small gaps to the actual
destination.

autotests/data/navitia/journey-bss-path-no-instr-start-coord.out.json

@@ -998,7 +998,7 @@
             {
                 "co2Emission": 0,
                 "disruptionEffect": "NormalService",
-                "distance": 903,
+                "distance": 946,
                 "from": {
                     "latitude": 43.61103439331055,
                     "locality": "Toulouse",
@@ -1421,6 +1421,26 @@
                                     [
                                         1.449293,
                                         43.605075
+                                    ],
+                                    [
+                                        1.449445,
+                                        43.604922
+                                    ],
+                                    [
+                                        1.449511,
+                                        43.604856
+                                    ],
+                                    [
+                                        1.449511,
+                                        43.604856
+                                    ],
+                                    [
+                                        1.449574,
+                                        43.604794
+                                    ],
+                                    [
+                                        1.4496145,
+                                        43.6047494
                                     ]
                                 ],
                                 "type": "LineString"

autotests/data/navitia/journey-response.out.json

@@ -486,6 +486,10 @@
                                         2.375607,
                                         48.844946
                                     ],
+                                    [
+                                        2.3772637747,
+                                        48.8440520493
+                                    ],
                                     [
                                         2.3772637747,
                                         48.8440520493
@@ -1185,6 +1189,10 @@
                                         2.378791,
                                         48.843228
                                     ],
+                                    [
+                                        2.3772637747,
+                                        48.8440520493
+                                    ],
                                     [
                                         2.3772637747,
                                         48.8440520493
@@ -1844,6 +1852,10 @@
                                         2.375607,
                                         48.844946
                                     ],
+                                    [
+                                        2.3772637747,
+                                        48.8440520493
+                                    ],
                                     [
                                         2.3772637747,
                                         48.8440520493
@@ -1873,7 +1885,7 @@
             {
                 "co2Emission": 0,
                 "disruptionEffect": "NormalService",
-                "distance": 510,
+                "distance": 511,
                 "from": {
                     "latitude": 49.00423812866211,
                     "locality": "Le Mesnil-Amelot",
@@ -1982,6 +1994,10 @@
                                     [
                                         2.564656983,
                                         49.0033055366
+                                    ],
+                                    [
+                                        2.564653,
+                                        49.003387
                                     ]
                                 ],
                                 "type": "LineString"
@@ -2163,6 +2179,10 @@
                                         2.375607,
                                         48.844946
                                     ],
+                                    [
+                                        2.3772637747,
+                                        48.8440520493
+                                    ],
                                     [
                                         2.3772637747,
                                         48.8440520493

src/lib/backends/navitiaparser.cpp

@@ -234,6 +234,13 @@ static Path parsePathFromLength(const QPolygonF &pathLineString, const QJsonArra
         pathSections.push_back(std::move(pathSec));
     }
 
+    // if there's a trailing polygon end, attached that to the last section
+    if (prevPolyIdx + 1 < pathLineString.size()) {
+        auto poly = pathSections.back().path();
+        std::copy(pathLineString.begin() + prevPolyIdx + 1, pathLineString.end(), std::back_inserter(poly));
+        pathSections.back().setPath(std::move(poly));
+    }
+
     Path path;
     path.setSections(std::move(pathSections));
     return path;