From f6661b8e77009e01ed5f7de93445847e82c94c92 Mon Sep 17 00:00:00 2001
From: David Speck <davidjakob.speck@gmail.com>
Date: Tue, 30 Jan 2024 19:23:26 +0100
Subject: [PATCH] fixed prepearbucket function which can lead to non-optimal
 plans for bidirectional search in rare cases

---
 src/search/symbolic/searches/uniform_cost_search.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/search/symbolic/searches/uniform_cost_search.cc b/src/search/symbolic/searches/uniform_cost_search.cc
index 329529e02..2a6fa0c30 100644
--- a/src/search/symbolic/searches/uniform_cost_search.cc
+++ b/src/search/symbolic/searches/uniform_cost_search.cc
@@ -155,7 +155,10 @@ void UniformCostSearch::stepImage(int maxTime, int maxNodes) {
             }
         }
     }
-    prepareBucket();
+    
+    while (!frontier.bucketReady() && !open_list.empty()) {
+        prepareBucket();
+    }
 
     engine->setLowerBound(getG() + mgr->getAbsoluteMinTransitionCost());
     step_estimation.set_data(step_timer(), stepNodes, !res_expansion.ok);