Thanks for the report @patrikwa. This commit has changed the behaviour of DragAndDropContainer::performExternalDragDropOfFiles() and ::performExternalDragDropOfText() so that they are asynchronous operations on all platforms (previously only Windows was synchronous) and the docs have been updated to reflect this. This means that the operation will no longer block the message thread on Windows as it runs on a separate background thread, but you can pass the methods a callback parameter which will be called when the operation has ended.
Hopefully you’ll agree that uniformly doing this asynchronously is a better solution and you should be able to work around any issues that arise using the callback, but feel free to post back if you have any issues.