Cloudfront does not currently support invalidating paths containing tilde character (~). Attempting to do it will throw an error: "Your request contains one or more invalid invalidation paths". This will fill up the logs with errors and fill the purge queue unnecessarily.
1. Have this module installed and configured along with purge_queuer_url
2. Create a page with URL /a~b
3. Visit it incognito
4. Edit the page title
5. Notice the page is now in the purge queue
6. Run cron
7. Notice the error in dblog and the item being stuck in queue
The only workaround that I could find is to replace tilde and everything after with a "*" during invalidation (e.g. /my-page?q=lorem~ipsum becomes /my-page?q=lorem*). While this could result in invalidating more cached pages than necessary, I believe it is better than to have the items stuck in queue.
Needs review
2.0
Code
Interesting. The tilde ~ character doesn't normally need to be URL encoded. I wonder if using the unicode equivalent %7E would work?