Electric behavior of dollar sign using AUCTeX

Question

I'm trying to turn $...$ into an electric pair, just as say (...). So I tried this solution, and it works fine on my older machine, running Emacs 24.3.1 and AUCTeX 11.87. However, on a newer installation (Emacs 24.5.1, AUCTeX 12.1.1), it doesn't quite behave like it should. When I type $x+y$, it should be giving me

$x+y$^,

where ^ denotes point. But instead I get

$x+y$^$$.

Obviously, Emacs fails to move over the automatically-inserted closing $ and instead inserts a new pair. Here is the relevant part of my .emacs:

(electric-pair-mode 1)
(define-key LaTeX-mode-map (kbd "$") 'self-insert-command)
(push '(?\$ . ?\$) electric-pair-pairs)

The push line may be included or not, it doesn't make a difference. I also tried the following .emacs, as suggested by the AUCTeX manual:

(electric-pair-mode 1)
(set (make-variable-buffer-local 'TeX-electric-math) (cons "$" "$"))

This gives me $x+y$^$, which is not much better. How do I get the behavior I want?

Answer 1

As I explained in my comment, this is a bug. Until it is fixed, you can work around it like so

(add-hook 'LaTeX-mode-hook
          'fix-electric-pair-paired-delimiters-in-tex-mode)

(defun fix-electric-pair-paired-delimiters-in-tex-mode ()
  (add-function
   :around
   (local 'electric-pair-skip-self)
   (lambda (oldfun c)
     (pcase (electric-pair-syntax-info c)
       (`(,syntax ,_ ,_ ,_)
        (if (eq syntax ?$)
            (unwind-protect
                (progn
                  (delete-char -1)
                  (texmathp))
              (insert-char c))
          (funcall oldfun c)))))
   '((name . fix-electric-pair-paired-delimiters-in-tex-mode))))