fix: always adopt outbound pickup price for inbound when set

src/BusProNet/XmlParser/TravelParser.php

@@ -87,8 +87,8 @@ class TravelParser extends AbstractParser
         $travel->pickups = $this->getPickups($node->filterXPath('.//zustiege/zustieg'), $dateFrom, true);
         $travel->dropOffs = $this->getPickups($node->filterXPath('.//zustiege_rueck/zustieg_rueck'), $dateTo, false);
 
-        // Merge drop-off prices into pickups for split pricing support
-        $this->mergeDropOffPricesIntoPickups($travel->pickups, $travel->dropOffs);
+        // A boarding point costs the same in both directions
+        $this->levelBoardingPointPrices($travel->pickups, $travel->dropOffs);
 
         $travel->guide = $this->getGuide($node);
 
@@ -453,22 +453,38 @@ class TravelParser extends AbstractParser
     }
 
     /**
-     * Merges drop-off prices into pickups for split pricing support.
+     * Levels the price of a boarding point across both travel directions.
      *
-     * For each pickup, finds the matching drop-off by ID and copies
-     * the inbound price to the pickup's priceInbound property. This enables
-     * split pricing calculations where costs are distributed between outbound
-     * and inbound transportation.
+     * A boarding point is either free or costs the same in both directions:
+     * `ZustiegPreis` is keyed by (point, tariff scheme) and holds no per-leg price, so
+     * BusPro bills an `Abfahrtsortzuschlag` per leg at one and the same rate. An
+     * asymmetric pair is therefore always an export defect — on some products a
+     * `<zustieg_rueck>` carries no `preis` although the engine still charges the return
+     * leg — and the stated price is the one that applies to both legs.
+     *
+     * Where both directions state a price they agree in practice; the outbound one wins
+     * to keep the outcome deterministic. Points without a counterpart are left as they are.
      *
      * @param array<int, Pickup> $pickups  Pickups indexed by ID (modified in place)
-     * @param array<int, Pickup> $dropOffs Drop-offs indexed by ID
+     * @param array<int, Pickup> $dropOffs Drop-offs indexed by ID (modified in place)
      */
-    private function mergeDropOffPricesIntoPickups(array &$pickups, array $dropOffs): void
+    private function levelBoardingPointPrices(array &$pickups, array $dropOffs): void
     {
-        foreach ($pickups as $pickupId => $pickup) {
-            if (isset($dropOffs[$pickupId])) {
-                $pickup->priceInbound = $dropOffs[$pickupId]->priceInbound;
+        foreach ($dropOffs as $pickupId => $dropOff) {
+            if (false === isset($pickups[$pickupId])) {
+                continue;
             }
+
+            $pickup = $pickups[$pickupId];
+            $price = $pickup->price ?? $dropOff->price;
+
+            $pickup->price = $price;
+            $pickup->priceOutbound = $price;
+            $pickup->priceInbound = $price;
+
+            $dropOff->price = $price;
+            $dropOff->priceOutbound = $price;
+            $dropOff->priceInbound = $price;
         }
     }