source/blender/nodes/NOD_socket_declarations.hh

@@ -158,7 +158,11 @@ class StringBuilder : public SocketDeclarationBuilder<String> {
 class IDSocketDeclaration : public SocketDeclaration {
  public:
   const char *idname;
-  /** Get the default ID pointer for this socket. This is a function to avoid dangling pointers. */
+  /**
+   * Get the default ID pointer for this socket. This is a function to avoid dangling pointers,
+   * since bNode::id pointers are remapped as ID pointers change, but pointers in socket
+   * declarations are not managed the same way.
+   */
   std::function<ID *(const bNode &node)> default_value_fn;
 
  public:

source/blender/nodes/intern/node_common.cc

@@ -140,6 +140,7 @@ static std::function<ID *(const bNode &node)> get_default_id_getter(const bNodeT
     const bNodeTree &ntree = *reinterpret_cast<const bNodeTree *>(node.id);
     const bNodeSocket *io_socket;
     if (in_out == SOCK_IN) {
+      /* Better be save than sorry when the underlying node group changed. */
       if (socket_index < ntree.interface_inputs().size()) {
         io_socket = ntree.interface_inputs()[socket_index];
       }