Require at least one element in interactive dialogs (#10003)

api4/integration_action.go

@@ -59,6 +59,11 @@ func openDialog(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if dialog.Dialog.Elements == nil || len(dialog.Dialog.Elements) == 0 {
+		c.SetInvalidParam("dialog.elements")
+		return
+	}
+
 	if err := c.App.OpenInteractiveDialog(dialog); err != nil {
 		c.Err = err
 		return