sql-connect-mysql dies if sql-port is nil (the default)

[rogers-emacs]

   To reproduce, simply do "emacs -Q", then invoke "M-x sql-mysql", and
give it some random database parameters.  It is not necessary to have a
valid database, or even a working server, as emacs dies before starting
the client.  See below for a simple fix.

                                        -- Bob Rogers
                                           http://www.rgrjr.com/

------------------------------------------------------------------------
diff --git a/lisp/progmodes/sql.el b/lisp/progmodes/sql.el
index e4df102..19e60da 100644
*** a/lisp/progmodes/sql.el
--- b/lisp/progmodes/sql.el
***************
*** 3119,3125 ****
        (setq params (append (list sql-database) params)))
      (if (not (string= "" sql-server))
        (setq params (append (list (concat "--host=" sql-server)) params)))
!     (if (not (and sql-port (numberp sql-port)))
        (setq params (append (list (concat "--port=" (number-to-string 
sql-port))) params)))
      (if (not (string= "" sql-password))
        (setq params (append (list (concat "--password=" sql-password)) 
params)))
--- 3119,3125 ----
        (setq params (append (list sql-database) params)))
      (if (not (string= "" sql-server))
        (setq params (append (list (concat "--host=" sql-server)) params)))
!     (if (and sql-port (numberp sql-port))
        (setq params (append (list (concat "--port=" (number-to-string 
sql-port))) params)))
      (if (not (string= "" sql-password))
        (setq params (append (list (concat "--password=" sql-password)) 
params)))