split edge: check, copy paste: check with a little bug

src/state-manager.h

@@ -49,22 +49,38 @@ class AppState{
 
 			VEC_SPTR_Edge copy_connections;
 			for(auto n : nodes){
-				std::ranges::copy_if(n->connections.begin(), n->connections.end(), std::back_inserter(copy_connections), [nodes](SPTR_Edge e){ return std::ranges::contains(nodes, e->start) && std::ranges::contains(nodes, e->end);});
+				for(auto c : n->connections){
+					if(std::ranges::contains(nodes, c->start) && std::ranges::contains(nodes, c->end)) {
+						copy_connections.push_back(std::make_shared<Edge>(*c));
+					}
+				}
 			}
+			std::cout << copy_connections.size() << std::endl;
+
+			for(auto old_node : nodes){
+				SPTR_Node new_node;
+
+				if(old_node->getNodeType() == NodeType::MIDINODE) {
+					new_node = gm.copyNode(std::dynamic_pointer_cast<MidiNode>(old_node), position + old_node->drag_offset);
+				} else {
+					new_node = gm.copyNode(old_node, position + old_node->drag_offset);
+				}
 
-			for(auto n : nodes){
-				SPTR_Node old_node = n;
-				SPTR_Node new_node = gm.copyNode(n, position + n->drag_offset);
 				new_node->copied = false;
 				new_node->selected = false;
 
 				for(auto c : copy_connections){
-					if(c->start == old_node) c->start = new_node;
-					if(c->end == old_node) c->end = new_node;
+					if(c->start == old_node) {
+						c->start = new_node;
+						c->start->connections.push_back(c);
+					}
+					if(c->end == old_node) {
+						c->end = new_node;
+						c->end->connections.push_back(c);
+					}
 				}
 			}
-
-			gm.edges.insert(gm.edges.end(), copy_connections.cbegin(), copy_connections.cend());
+			std::ranges::copy(copy_connections.begin(), copy_connections.end(), std::back_inserter(gm.edges));
 		}
 
 		void removeNodes(VEC_SPTR_Node nodes){
@@ -103,6 +119,10 @@ class AppState{
 				s->start = s->next;
 			}
 
+			for(auto n : adjacent_nodes){
+				std::erase_if(n->connections, [n, nodes](SPTR_Edge c){ return std::ranges::contains(nodes, c->start) || std::ranges::contains(nodes, c->end);});
+			}
+			
 			for(auto n : nodes){
 				std::erase_if(gm.edges, [n](SPTR_Edge c){ return c->start == n || c->end == n;});
 			}