var urlResolver = ServiceLocator.Current.GetInstance<UrlResolver>();

var url = urlResolver.GetUrl(contentReference, language);

Thank you Daniel,

However, I can't put this into context.

We're doing this from a webservice, i.e. it has no connection to visiting the pages in question, we're getting these pages using the following order (pseudocode):

PageDataCollection children = DataFactory.Instance.GetChildren();

PageDataCollection langBranches = DataFactory.Instance.GetLanguageBranches();

foreach (PageData page in langBranches)

Here, the PageData object contains these strange urls (while they do redirect to the correct page, it's not the ones we're looking for).

Thanks,

Mattias

Apparently StaticLinkURL seems to be correct, it's supposed to be "/link/randomhash".

The issue seems to occur in the following statement:

UrlRewriteProvider.ConvertToExternal(ub, page.PageLink, System.Text.UTF8Encoding.UTF8);

Comparing EPi8 to EPi9, this is where it becomes the true external URI, while in EPi9 it remains as "/link/randomhash".

Code:

if (page.LinkType != PageShortcutType.External)
{
	UrlBuilder ub = new UrlBuilder(UriSupport.Combine(hostUrl, page.StaticLinkURL + "&epslanguage=" + page.LanguageBranch));
	UrlRewriteProvider.ConvertToExternal(ub, page.PageLink, System.Text.UTF8Encoding.UTF8);
	path = ub.Path;
}

Where path in this case becomes the true external URI.

I can't understand why it works in all previous versions of EPi but not EPi9, any help is appreciated.

They've changed a lot in that part. UrlResolver is your new best buddy for creating external urls basically. The rest is legacy code that might work still and will probably be removed in the future. 

You can also check out

http://world.episerver.com/Forum/Developer-forum/-EPiServer-75-CMS/Thread-Container/2014/4/Get-friendly-Url-from-Url-property/

Thank you Daniel, that helped.

For anyone else who previously used UrlRewriteProvider and is having problems, the fix is embarrassingly easy:

path = UrlResolver.Current.GetUrl(page.PageLink, page.LanguageBranch);

Instead of:

UrlBuilder ub = new UrlBuilder(UriSupport.Combine(hostUrl, page.StaticLinkURL + "&epslanguage=" + page.LanguageBranch));
UrlRewriteProvider.ConvertToExternal(ub, page.PageLink, System.Text.UTF8Encoding.UTF8);
path = ub.Path;

However, I am slightly unsure if this will handle them as UTF8 automatically (hence System.Text.UTF8Encoding.UTF8).

EDIT: Just tested it, seems to work just fine.

Sweet!