Development Branch: Loading Non-Cached Old URLs That Have '+'

[nyanginator]

Currently, old URLs from the URL history only work when there are spaces ' ' instead of '+' signs. For example, let's say:

• Course with shortname "My Course" has clean url: http://www.example.com/moodle/course/My+Course
• Shortname is changed to "My Cool Course". Upon saving this edit, it loads the page with the old URL since it is cached, so still: http://www.example.com/moodle/course/My+Course
• Purge all caches so that on the next try, it will need to load from the URL history in the database.
• The old URL should still load since it is in the URL history. But trying to load http://www.example.com/moodle/course/My+Course results in "Sorry, the requested file could not be found".
• Change all '+' signs to spaces ' ' (http://www.example.com/moodle/course/My Course) and the page loads fine, redirecting to the new clean URL: http://www.example.com/moodle/course/My+Cool+Course

Notes:

• Same behavior applies to course modules, since course module URLs have the course URL in them.
• The most current URL works, regardless of whether there are spaces ' ' or '+' signs. Only loading of old URLs with '+' signs don't work.
• The database stores clean URLs without the '+' signs. This is probably why only old URLs without '+' signs work.
• The '+' signs come from cleaning URLs using the urlencode() function in classes/local/cleaner/cleaner.php.
• Is there any reason why clean_moodle_url::sluggify() is used only to clean some paths, and urlencode() is used for others? Wouldn't it be better to keep everything consistent with sluggify()?