Language context menu appearing outside the editor

Environment-test2, beta

1> Insert some Language in RTL direction.
2> insert a comment in the language text, right before the last word. Notice the word moves to the start of line.
3> Now place the cursor at the end of the last char in the langauge text, notice the language context menu appears outside the editor on the top left of page.See screenshot.

It happens only when the cursor is at the last character.

Refer bug 71320 screencast, in case the above steps sound confusing.

Version: unspecified
Severity: normal

Attached: