[upstream] CKEditor's Moono skin does not respect the CKEditor cache-busting query string when loading its icons sprite

This is a browser cache issue: the icons.png image sprite has changed since version 8.0, but your browser still has it cached. Clearing the browser cache, or doing a hard refresh of this page (CTRL/CMD+R) would fix it.

However … #2679903: CKEditor uses separate cache-busting query string from Drupal's should have fixed that. But I see now that the image sprite is requested without the cache-busting query string — CKEditor seems to only use that for plugins it requests. This appears to be the case because it is requested from CSS. I'm not sure if there's anything we can do about that. Assigning to @mlewand from the CKEditor team.

See http://docs.ckeditor.com/#!/api/CKEDITOR-property-timestamp — which says:

A constant string unique for each release of CKEditor. Its value is used, by default, to build the URL for all resources loaded by the editor code, guaranteeing clean cache results when upgrading.

However, clearly, that is not happening.

Confirmed by the CKEditor team:

reinmar [11:49 AM]  Yup, that’s a sad truth – cache busting does not cover icons. We were planning to fix it, but we lost the only guy who had time and knowledge about the CKBuilder (cause that’s not CKEditor’s fault itself) :(.
wimleers [11:50 AM]  right
wimleers [11:51]  yeah the fact that it's loaded from CSS makes it hard
wimleers [11:51]  But it'd be great if the documentation for `CKEDITOR.timestamp` could be updated in the mean time, and preferably even link to a ticket
wimleers [11:51]  Better to be honest about the gotchas :)
reinmar [12:38 PM] That’s true. Especially, that it doesn’t seem that we have resources to work on this fix. I’m sad that we actually lost two guys who could do this… life.

Nothing Drupal can do here.

It's issue #10685 in CKEditor's tracker.

Reported again today: #2709753: Wrong icons at CKEditor.

As indicated in http://ckeditor.com/blog/CKEditor-Biweekly-for-April-26-2016, this is being fixed upstream! :) :) So, hopefully in a patch release of 8.1, and otherwise in 8.2 and other versions, this won't be a problem anymore.

Just came across this upgrading from 8.0.6 -> 8.1.0 with a fairly vanilla Drupal 8 site.

This is going to rain confusion over everyone. No amount of cache clearing, or force reloading seems to fix this either.

Edit - after dumping the entire browser caching of images and files (637MB worth) the issue is resolved.

removing issue summary images that should not be there.

Reflecting that this is blocked on upstream.

As @wiifm said,

after dumping the entire browser caching of images and files (637MB worth) the issue is resolved.

I did the same in Google Chrome:

We've been able to push it earlier into 4.5.9 version which just has released. Please confirm if it fixes the problem for you.

Reflecting what #11 states.

This is now still postponed, it's blocked on #2724225: Update CKEditor library to 4.5.9, which I just RTBC'd.

#2724225: Update CKEditor library to 4.5.9 landed, which fixed this! :)