focus text input on popup dialogs

src/node_dialog_layer_rename.cpp

@@ -42,3 +42,10 @@ std::string NodeDialogLayerRename::get_name()
 {
     return input ? input->m_text : "";
 }
+
+void NodeDialogLayerRename::added(Node* parent)
+{
+    Node::added(parent);
+    if (added_to_root())
+        input->key_capture();
+}