bug#14000: 24.3.50; electric-pair-post-self-insert-function does not handle nested parentheses

[Carsten Bormann]

In electric-pair-mode, I type "(("

I get "(()"

I should get "(())"

Fix below.

In GNU Emacs 24.3.50.1 (x86_64-apple-darwin, NS apple-appkit-1038.36)
 of 2013-03-19 on bob.porkrind.org
Bzr revision: 112090 dgutov@yandex.ru-20130319050649-jie5ixrjvsavih4i
Windowing system distributor `Apple', version 10.3.1187
Configured using:
 `configure --host=x86_64-apple-darwin --build=i686-apple-darwin
 --with-ns'

--- electric.el 2013-03-19 18:51:05.000000000 +0100
+++ electric-fixed.el   2013-03-19 18:55:59.000000000 +0100
@@ -354,7 +354,10 @@
                ;; I find it more often preferable not to pair when the
                ;; same char is next.
                (eq last-command-event (char-after))
-               (eq last-command-event (char-before (1- (point))))
+               (and
+                (eq last-command-event (char-before (1- (point))))
+                (not (eq syntax ?\())
+               )
                ;; I also find it often preferable not to pair next to a word.
                (eq (char-syntax (following-char)) ?w)))
       (save-excursion (insert closer))))))