Jetpack: Photon: URLs with & in RSS feeds are not being encoded correctly

[chaselivingston]

Steps to reproduce the issue

1. Try adding an extra parameter to a Photon URL via a function.
2. Notice that the parameter is added in a query string with an & character.
3. This is not encoded correctly and thus causes RSS feed validation errors.

Example feed with this issue: http://offbeatbride.com/feed/

[kellbot]

Just a heads up - this is no longer visible at http://offbeatbride.com/feed/. We had to disable the filter as a broken RSS feed is a showstopper for us. Thanks!

[stale[bot]]

This issue has been marked as stale. This happened because:

• It has been inactive in the past 6 months.
• It hasn’t been labeled `[Pri] Blocker`, `[Pri] High`.

No further action is needed. But it's worth checking if this ticket has clear reproduction steps and it is still reproducible. Feel free to close this issue if you think it's not valid anymore — if you do, please add a brief explanation.

[janboddez]

My feed reader won't refresh feeds with unescaped ampersands in URLs. In one such, recent example, the invalid URL was the one inside the icon tags, ending in &ssl rather than &ssl. Can't image this is hard to fix.

[jeherve]

@tw2113 reported a similar issue in #13722.

Annoyingly, I can't seem to reproduce the issue on my own site right now:
https://www.feedvalidator.org/check.cgi?url=https%3A%2F%2Fjeremy.hu%2Ffeed%2Fatom%2F

As you can see, the icon URL is encoded there:
<icon>https://i0.wp.com/jeremy.hu/wp-content/uploads/big-big-favicon-site_icon.png?fit=32%2C32&#038;quality=80&#038;ssl=1</icon>

@tw2113 Do you happen to use another plugin that may output things in the RSS feed on that site? I wonder if this may be a conflict with another plugin at play.

[tw2113]

I can't say on other plugins part, as this wasn't found/demo'd using my own websites. I had noticed it as i tried to subscribe to others' websites and their atom rss feed. I could try to reach out to the site owner and see if they'd share their current plugin list.

The encoding part looks legit though, as my example one does NOT encode that last & like your personal one does. That'd be an interesting one to stack trace through.

[jeherve]

Also reported in 2726497-zen with the feeds created by the PodLove plugin.

[jeherve]

This was also reported here:
https://wordpress.org/support/topic/can-i-bypass-jetpack-photon-for-a-specific-field/