In a popover that contains a single line of text, the usable message area ("content") height is twice as smaller as the entire popover height (yellow area), which makes it extremely hard to mouse-over, in order to leave the popover visible until mouse-out.
A user is also misled into thinking they are going to hit the popover, since the mouse pointer is rested over the yellow-colored area which visually pertains to the popover content, but in fact it is not.
I can look at this, I have a version of the popover that works well as a single line.
(In reply to comment #1)
> I can look at this, I have a version of the popover that works well as a single
Bug description is misleading. Problem is that when user is moving mouse from evaluated expression to a popover, he needs to reach popover content in order to prevent popover from disappearing. Now in case of text, popover content is a span and it does not occupy entire popover area horizontally. As a result, user reaches what he thinks is a popover, but popover still disappears.
Furthermore, guys here claim that popover border is not considered a part of popover...
Right, the popover border is not considered a part of popover, since the shadow would be considered too.
That could be fixed too with another positioned element used for hit testing.