bug#1267: Emacsclient can't find terminal in daemon mode

[Chong Yidong <cyd@stupidchicken.com>]

How bout something on these lines?

The effect is that instead of signalling an error when no -t or -c is
passed and no usable frame exists, Emacs opens the tty of the calling
emacsclient.


*** trunk/lib-src/emacsclient.c.~1.135.~	2008-10-29 11:38:04.000000000 -0400
--- trunk/lib-src/emacsclient.c	2008-10-29 23:10:45.000000000 -0400
***************
*** 1437,1443 ****
        send_to_emacs (emacs_socket, " ");
      }
  
!   if (tty)
      {
        char *type = egetenv ("TERM");
        char *tty_name = NULL;
--- 1437,1443 ----
        send_to_emacs (emacs_socket, " ");
      }
  
!   if (tty || current_frame)
      {
        char *type = egetenv ("TERM");
        char *tty_name = NULL;

*** trunk/lisp/server.el.~1.170.~	2008-10-29 11:38:05.000000000 -0400
--- trunk/lisp/server.el	2008-10-29 23:48:42.000000000 -0400
***************
*** 810,815 ****
--- 810,816 ----
  		dontkill       ; t if the client should not be killed.
                  (commands ())
  		dir
+ 		use-current-frame
                  (tty-name nil)       ;nil, `window-system', or the tty name.
                  tty-type             ;string.
  		(files nil)
***************
*** 830,836 ****
  		 ((equal "-nowait" arg) (setq nowait t))
  
  		 ;; -current-frame:  Don't create frames.
! 		 ((equal "-current-frame" arg) (setq tty-name nil))
  
  		 ;; -display DISPLAY:
  		 ;; Open X frames on the given display instead of the default.
--- 831,837 ----
  		 ((equal "-nowait" arg) (setq nowait t))
  
  		 ;; -current-frame:  Don't create frames.
! 		 ((equal "-current-frame" arg) (setq use-current-frame t))
  
  		 ;; -display DISPLAY:
  		 ;; Open X frames on the given display instead of the default.
***************
*** 926,937 ****
  		 ;; Unknown command.
  		 (t (error "Unknown command: %s" arg))))
  
!             (setq frame
!                   (case tty-name
!                     ((nil) (if display (server-select-display display)))
!                     ((window-system)
!                      (server-create-window-system-frame display nowait proc))
!                     (t (server-create-tty-frame tty-name tty-type proc))))
  
              (process-put
               proc 'continuation
--- 927,940 ----
  		 ;; Unknown command.
  		 (t (error "Unknown command: %s" arg))))
  
! 	    (cond ((and use-current-frame
! 			(not (and (daemonp)
! 				  (= (length (frame-list)) 1)
! 				  (eq (selected-frame) terminal-frame))))
! 		   (if display (server-select-display display)))
! 		  ((eq tty-name 'window-system)
! 		   (server-create-window-system-frame display nowait proc))
! 		  (t (server-create-tty-frame tty-name tty-type proc)))
  
              (process-put
               proc 'continuation