From d58a6e613be02bd200db0566d040cc89d3df8f97 Mon Sep 17 00:00:00 2001
From: kishorenc <kishorenc@gmail.com>
Date: Thu, 14 Nov 2019 11:06:57 +0530
Subject: [PATCH] Handle edge case of finding no query tokens in the array.

---
 src/collection.cpp | 23 ++++++++++++++---------
 src/index.cpp      |  6 +++---
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/collection.cpp b/src/collection.cpp
index 1041d2f3..5f1fca1b 100644
--- a/src/collection.cpp
+++ b/src/collection.cpp
@@ -738,25 +738,25 @@ void Collection::highlight_result(const field &search_field,
         // is from the best matched field and need not be present in other fields of a document.
         Index* index = indices[field_order_kv.key % num_indices];
         art_leaf *actual_leaf = index->get_token_leaf(search_field.name, &token_leaf->key[0], token_leaf->key_len);
-        if(actual_leaf != NULL) {
+        if(actual_leaf != nullptr) {
             query_suggestion.push_back(actual_leaf);
             std::vector<uint16_t> positions;
             uint32_t doc_index = actual_leaf->values->ids.indexOf(field_order_kv.key);
-            uint32_t *indices = new uint32_t[1];
-            indices[0] = doc_index;
-            leaf_to_indices.emplace(actual_leaf, indices);
+            auto doc_indices = new uint32_t[1];
+            doc_indices[0] = doc_index;
+            leaf_to_indices.emplace(actual_leaf, doc_indices);
         }
     }
 
+    if(query_suggestion.empty()) {
+        // none of the tokens from the query were found on this field
+        return ;
+    }
+
     // positions in the field of each token in the query
     std::vector<std::vector<std::vector<uint16_t>>> array_token_positions;
     Index::populate_token_positions(query_suggestion, leaf_to_indices, 0, array_token_positions);
 
-    if(array_token_positions.size() == 0) {
-        // none of the tokens from the query were found on this field
-        return ;
-    }
-
     std::vector<match_index_t> match_indices;
 
     for(size_t array_index = 0; array_index < array_token_positions.size(); array_index++) {
@@ -771,6 +771,11 @@ void Collection::highlight_result(const field &search_field,
         match_indices.push_back(match_index_t(this_match, this_match_score, array_index));
     }
 
+    if(match_indices.empty()) {
+        // none of the tokens from the query were found on this field
+        return ;
+    }
+
     const size_t max_array_matches = std::min((size_t)MAX_ARRAY_MATCHES, match_indices.size());
     std::partial_sort(match_indices.begin(), match_indices.begin()+max_array_matches, match_indices.end());
 
diff --git a/src/index.cpp b/src/index.cpp
index 6a5b5c42..7492e36c 100644
--- a/src/index.cpp
+++ b/src/index.cpp
@@ -859,7 +859,7 @@ void Index::collate_curated_ids(const std::string & query, const std::string & f
         uint64_t match_score = 0;
 
         for(const std::vector<std::vector<uint16_t>> & token_positions: array_token_positions) {
-            if(token_positions.size() == 0) {
+            if(token_positions.empty()) {
                 continue;
             }
             const Match & match = Match::match(seq_id, token_positions);
@@ -1228,7 +1228,7 @@ void Index::score_results(const std::vector<sort_by> & sort_fields, const uint16
             populate_token_positions(query_suggestion, leaf_to_indices, i, array_token_positions);
 
             for(const std::vector<std::vector<uint16_t>> & token_positions: array_token_positions) {
-                if(token_positions.size() == 0) {
+                if(token_positions.empty()) {
                     continue;
                 }
                 const Match & match = Match::match(seq_id, token_positions);
@@ -1288,7 +1288,7 @@ void Index::populate_token_positions(const std::vector<art_leaf *> &query_sugges
     // for every element in a potential array, for every token in query suggestion, get the positions
 
     // first ascertain the size of the array
-    size_t array_size = 1;
+    size_t array_size = 0;
 
     for (const art_leaf *token_leaf : query_suggestion) {
         size_t this_array_size = 1;