Why doesn't the "Share" widget on VKontakte work?

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Let's say I want to make a share button on the site, but it will not be the current page, but a third-party one:

http://oauth.vk.com/authorize?client_id=-1&redirect_uri=http%3A%2F%2Fvk.com%2Fshare.php%3Furl%3Dhttp%253A%252F%252Fvk.com%252F%26title%3D%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%26description%3D%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%25D1%2582%25D0%25B5%25D1%2581%25D1%2582%2520%26image%3D&display=widget

If the person was authorized at the moment of clicking on the link, everything is OK, but if not, the "too long to param" error occurs, what's the problem?