SharePoint 2013 redirects are duplicating query string

Question

I've got a weird one. I've just migrated to SharePoint 2013 doing a DB upgrade on a new server, as opposed to in-place. I've got the old SharePoint domain name (my.xxx.local) pointing at the new server (sharepoint.xxx.local), which redirects as expected, except any URL with a query string, has the contents of that query string duplicated when redirected. For example, http://my.xxx.local/Pages/Welcome.aspx?id=4 becomes http://sharepoint.xxx.local/Pages/Welcome.aspx?id=4&id=4. SharePoint doesn't like the duplicate query string obviously, and either bombs or doesn't show the content requested.

Does anyone know how I can even begin troubleshooting this? The IIS logs and SharePoint ULS logs show nothing.

Answer 1

I found the cause, and I feel like an idiot, especially considering I've spent like 3 hours on this. I had a redirect (URL Rewrite) configured up at the IIS root level which had was set to redirect to "http://sharepoint.xxx.local{REQUEST_URI}", but I also had the "Append query string" option checked. I would have configured this early in testing and had forgotten that you could even configure redirects at the root of IIS like that.