\overset & \underset don't allow editing of annotation

[NSoiffer]

Description

The notation for underset and overset is:
\overset{annotation}{base}

In the editor, you can not select or move the cursor into the annotation part of the construct.

Steps to Reproduce

1. In a math editor instance, type 1+\overset{x-1}{ax+by+c} followed by enter
2. The \overset is properly display
3. Try to arrow backwards -- you can't get to the 'x-1'
4. Try to select 'x-1' -- you can't

I tried this in both Chrome and Firefox.

[NSoiffer]

Related to this: if you select the entire expression, the x-1 it seems to be in some quantum selection state :-)

1. If you type delete or a character, the entire expr is deleted or replaced.
2. If you type /, only base is part of the fraction as shown below (selected the fraction)
   

[arnog]

Selection should work now.