Fix empty tree node iterator

[simongog#1]
jhrotko · Jun 2, 2020 · fa6ea84 · fa6ea84
1 parent 2470513
commit fa6ea84
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Showing 2 changed files with 9 additions and 10 deletions.
diff --git a/include/sdsl/k2_tree_iterator.hpp b/include/sdsl/k2_tree_iterator.hpp
@@ -457,9 +457,7 @@ namespace sdsl
             this->curr_j = other->curr_j;
         }
 
-        ~node_iterator()
-        {
-        }
+        ~node_iterator() {}
 
         value_type operator*() const
         {
@@ -486,17 +484,13 @@ namespace sdsl
             {
                 for (value_type j = curr_j; j < tree->get_number_nodes(); j++)
                     if (tree->adj(i, j))
-                    {
                         return update_state(i);
-                    }
                 for (value_type j = 0; j < tree->get_number_nodes(); j++)
                 {
                     if (j == i)
                         continue;
                     if (tree->adj(j, i))
-                    {
                         return update_state(i);
-                    }
                 }
                 curr_j = 0;
             }
@@ -513,6 +507,7 @@ namespace sdsl
 
         node_iterator<k2_tree> end()
         {
+            if(tree == NULL) return *this;
             node_iterator<k2_tree> it = *this;
             value_type num_nodes = it.tree->get_number_nodes();
             *(it._ptr) = it.tree->get_number_nodes(); //end node
@@ -542,7 +537,7 @@ namespace sdsl
 
             return *this;
         }
-    };
+    }; // namespace sdsl
 
 } // namespace sdsl
 

diff --git a/test/k2_tree_test.cpp b/test/k2_tree_test.cpp
@@ -394,14 +394,18 @@ TYPED_TEST(k2_tree_test_k_2, node_iterator_test) {
     node_iterator++;
     ASSERT_EQ(*node_iterator, (size_t)3);
 
-    node_iterator = tree.node_end();
-    ASSERT_EQ(*node_iterator, (size_t)4);
+    node_iterator++;
+    ASSERT_EQ(*node_iterator, *tree.node_end());
 
     auto other_iterator = tree.node_begin();
     swap(other_iterator, node_iterator);
     ASSERT_EQ(*other_iterator, *tree.node_end());
     ASSERT_EQ(*node_iterator, *tree.node_begin());
+}
 
+TYPED_TEST(k2_tree_test_k_2, node_iterator_empty) {
+    TypeParam empty_tree;
+    ASSERT_TRUE(empty_tree.node_begin() == empty_tree.node_end());
 }
 
 TYPED_TEST_CASE(k2_tree_test_k_3, k_3_implementations);