id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
26466	set_language with next unset and a urlencoded HTTP_REFERER fails redirection	Miikka Salminen	nobody	"POSTing to `set_language` when `next` is not set causes Django to user HTTP_REFERER instead. If the URL in HTTP_REFERER is urlencoded, the resulting redirection will fail.

The bug is caused by the call to `translate_url` function in `set_language`. `translate_url` passes the URL on to `reverse`, which assumes URLs that are not urlencoding, thus resulting in a double urlencoded URL, which obviously will not work. Non-urlencoded URLs in HTTP_REFERER work correctly.

An easy way to test this is to have a view with a URL with unicode characters in it and use the translation selector widget provided in the i18n docs, but with the `redirect_to` context variable undefined, which is the way I found the bug.

AFAIK there's no standard about whether the browser should encode the URL in HTTP_REFERER, but most of the new browsers do so anyway. The bug should be easy to fix, thus, by just decoding the string in HTTP_REFERER – if it was encoded, it will now be unencoded, if it was '''not''' encoded, it will be unchanged (disregarding a corner case of ambiguous URLs with substrings like `%C3%A4` verbatim with browsers that don't encode the URLs). I'll make a pull request within a few days."	Bug	new	Internationalization	1.9	Normal		set_language		Unreviewed	0	0	0	0	0	0