There is a bug in the newly added custom skin support patch:
https://www.drupal.org/project/ckeditor/issues/2671806#comment-13526746
https://git.drupalcode.org/project/ckeditor/-/blob/7.x-1.x/includes/cked...
https://git.drupalcode.org/project/ckeditor/commit/92b3637#26b32cb5bfe69...
In the last version of the patch, @vokiel changed the code to put a trim inside of a rtrim.
However the parentheses are missing, so it instead shows the call as rtrimtrim, which doesn't exist.
Comments
Comment #2
sgdev commentedComment #4
vokielGood catch @ron_s, thank you!
Comment #5
sgdev commentedIf this has been committed, it needs to be marked as fixed, not needs review.
Also, you're supposed to be giving credit to those who wrote the patch when committing it.