In the comment field, as soon as you type
@, there appears the auto-complete option to insert another poster's name you want to reply to.
If there is already some text in the comment field, and you move the text cursor to somewhere within the text (not to the end position), then type
@ and select a poster's name to insert, some comment text is overwritten. It seems that the text up to the next white-space is affected, the white-space itself and everything after is kept.
I expect the poster's name to be inserted at the location of the cursor, so I consider that behaviour as a bug actually.
Take this post, go to Add Comment, type
abc def gh (including the spaces), move text cursor between
e, then type
@; then select a suggested poster's name, for instance,
You'll see that
ef of the former comment text is overwritten, so the text is now
abc d@aschipfl gh.
What I expect is the comment text to be
abc d@aschipflef gh.
Optionally, and auto-inserted space behind the poster's name could also be helpful, so the text of the above example would look like
abc d@aschipfl ef gh then.
However this extra-space makes only sense if there isn't one yet and if the poster's name is not placed at end position of the text.