Last modified: 2014-09-15 17:59:49 UTC
Copied the heading "Lilypond source" and the line of text below from this page: https://commons.wikimedia.org/wiki/File:C_sharp_and_double_sharp_music.svg?veaction=edit Pasted it into a similar page, open in a different tab, and a grey circle containing a question mark appeared at the end, which I am reliably informed is a comment. (Abandoned my edit in the end, so there's nothing to clean up.)
The copied element here is just the LilyPond source template. Confirmed this bug in Win8/Chrome but not Ubuntu/Chrome. The comment inserted is <!-- EndFragment --> and comes from the clipboard API, not CE paste.
Change 160179 had a related patch set uploaded by Esanders: Strip Start/EndFragment comments from paste https://gerrit.wikimedia.org/r/160179
Change 160179 merged by jenkins-bot: Strip Start/EndFragment comments from paste https://gerrit.wikimedia.org/r/160179