overwrite previous tree definitions

Author: facontidavide

src/xml_parsing.cpp

@@ -222,7 +222,7 @@ void XMLParser::Pimpl::loadDocImpl(tinyxml2::XMLDocument* doc, bool add_includes
       tree_name = "BehaviorTree_" + std::to_string(suffix_count++);
     }
 
-    tree_roots.insert({tree_name, bt_node});
+    tree_roots[tree_name] = bt_node;
   }
 }
 
@@ -430,10 +430,9 @@ void VerifyXML(const std::string& xml_text,
 }
 
 Tree XMLParser::instantiateTree(const Blackboard::Ptr& root_blackboard,
-                                std::string main_tree_to_execute)
+                                std::string main_tree_ID)
 {
   Tree output_tree;
-  std::string main_tree_ID = main_tree_to_execute;
 
   // use the main_tree_to_execute argument if it was provided by the user
   // or the one in the FIRST document opened

tests/gtest_factory.cpp

@@ -341,3 +341,34 @@ TEST(
   Tree tree = factory.createTreeFromFile(path);
   ASSERT_EQ(NodeStatus::SUCCESS, tree.tickWhileRunning());
 }
+
+TEST(BehaviorTreeReload, ReloadSameTree)
+{
+  const char* xmlA = R"(
+<root main_tree_to_execute = "MainTree" >
+  <BehaviorTree ID="MainTree">
+    <AlwaysSuccess/>
+  </BehaviorTree>
+</root> )";
+
+  const char* xmlB = R"(
+<root main_tree_to_execute = "MainTree" >
+  <BehaviorTree ID="MainTree">
+    <AlwaysFailure/>
+  </BehaviorTree>
+</root> )";
+
+  BehaviorTreeFactory factory;
+
+  factory.registerBehaviorTreeFromText(xmlA);
+  {
+    auto tree = factory.createTree("MainTree");
+    ASSERT_EQ(NodeStatus::SUCCESS, tree.tickWhileRunning());
+  }
+
+  factory.registerBehaviorTreeFromText(xmlB);
+  {
+    auto tree = factory.createTree("MainTree");
+    ASSERT_EQ(NodeStatus::FAILURE, tree.tickWhileRunning());
+  }
+}