A colon in alt text breaks the image description

(Surprisingly this screenshot with an actual colon (:) is the first random small file i found, not what i was uploading and describing when i ran into this problem; i just put too much punctuation in my image descriptions.)

Related #2859006: Image alternative text loses text preceding colon upon leaving plain-text editor or upon saving node →

This is a Drupal Core issue: #2859006: Image alternative text loses text preceding colon upon leaving plain-text editor or upon saving node →