Re: Highlight opening parentheses in show-paren-mode

[Richard Stallman]

        When at the beginning of a valid parenthetical expression,
    SHOW-PAREN-FUNCTION in "paren.el" does not highlight the opening
    parenthesis.

The cursor normally highlights the open paren in that case.
It would look bad to put other highlighting on it.
However, it seems you use the bar cursor.  With the bar cursor,
this change would make sense.

Maybe we should test the cursor type there.