The output from RealDigits is complicated to use. Here is what I came up with:

normalizeDigitSequence =
  {{{beforeRecurring___, {recurring__}}, c_?NonPositive} :>
    {{0, beforeRecurring, {recurring}}, c + 1},
   {{beforeRecurring___, {recurring__}}, c_?Positive} /; 
     Length[{beforeRecurring}] < c :>
    {{beforeRecurring, First[{recurring}],
      RotateLeft[{recurring}]}, c}};
addOverlineToRepeating =
  {{beforeRecurring___, {recurring___}}, c_?Positive} /; 
    Length[{beforeRecurring}] >= c :>
   Row[Append[Insert[{beforeRecurring}, ".", c + 1],
     Overscript[Row[{recurring}], _]]];
RealDigits[13/7] //. normalizeDigitSequence /. addOverlineToRepeating

This is meant for display only. It does not evaluate to a number.

What is wrong with 130/7? I simply arranged for the ovlerline non to cross over the decimal point. I was not aware of OverBar, which is indeed shorter. However, Overscript is regularly documented. Curiously,

OverBar[x] === Overscript[x, _]

gives False, but if you evaluate

{OverBar[x], Overscript[x, _]}

and look at the underlying BoxData in the output cell, you will see that they are represented identically as OverscriptBox["x", "_"]. If you copy and paste one of them into an expression that expects the other, you may run into mysterious trouble.

What is wrong with 130/7? I simply arranged for the ovlerline non to cross over the decimal point.

That's the problem: for 130/7 the recurring digit sequence is incomplete, hence the output is wrong.

This code gives wrong result, for example, for 130/7.

Instead of using the undocumented (?) Overscript with a Blank as a second argument, one can also use OverBar.