From 70bb0829739bab0a49ce3bc2f2e8ae079c03b1b7 Mon Sep 17 00:00:00 2001
From: Patrick Niklaus <patrick.niklaus@student.kit.edu>
Date: Thu, 3 Sep 2015 10:40:16 +0200
Subject: [PATCH] Fix endless loop

---
 data_structures/hidden_markov_model.hpp |  1 +
 routing_algorithms/map_matching.hpp     | 12 ++++++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/data_structures/hidden_markov_model.hpp b/data_structures/hidden_markov_model.hpp
index 60738a561..15aa35b8b 100644
--- a/data_structures/hidden_markov_model.hpp
+++ b/data_structures/hidden_markov_model.hpp
@@ -96,6 +96,7 @@ template <class CandidateLists> struct HiddenMarkovModel
         path_lengths.resize(candidates_list.size());
         suspicious.resize(candidates_list.size());
         pruned.resize(candidates_list.size());
+        breakage.resize(candidates_list.size());
         for (const auto i : osrm::irange<std::size_t>(0u, candidates_list.size()))
         {
             const auto& num_candidates = candidates_list[i].size();
diff --git a/routing_algorithms/map_matching.hpp b/routing_algorithms/map_matching.hpp
index 0993b2eef..58b0ad1a8 100644
--- a/routing_algorithms/map_matching.hpp
+++ b/routing_algorithms/map_matching.hpp
@@ -301,14 +301,17 @@ class MapMatching final : public BasicRoutingInterface<DataFacadeT, MapMatching<
         {
             osrm::matching::SubMatching matching;
 
-            // find real end of trace
-            // not sure if this is really needed
             std::size_t parent_timestamp_index = sub_matching_end - 1;
             while (parent_timestamp_index >= sub_matching_begin &&
                    model.breakage[parent_timestamp_index])
             {
                 --parent_timestamp_index;
             }
+            while (sub_matching_begin < sub_matching_end &&
+                   model.breakage[sub_matching_begin])
+            {
+                ++sub_matching_begin;
+            }
 
             // matchings that only consist of one candidate are invalid
             if (parent_timestamp_index - sub_matching_begin + 1 < 2)
@@ -335,6 +338,11 @@ class MapMatching final : public BasicRoutingInterface<DataFacadeT, MapMatching<
 
                 reconstructed_indices.emplace_front(parent_timestamp_index, parent_candidate_index);
                 const auto &next = model.parents[parent_timestamp_index][parent_candidate_index];
+                // make sure we can never get stuck in this loop
+                if (parent_timestamp_index == next.first)
+                {
+                    break;
+                }
                 parent_timestamp_index = next.first;
                 parent_candidate_index = next.second;
             }