bug#1388: 23.0.60; Emacs shell problem with echo "1+1" | bc

[Glenn Morris]

Stefan Monnier wrote:

> Yes, an appropriate binding of process-connection-type at the right
> place and the right time should do the trick.

Awesome, thanks. The following seems to work, though:

i) One needs to use either /bin/echo or set eshell-plain-echo-behavior
non-nil if `echo 1+1 | bc' is to work.

ii) I'm not sure whether the following is mistakenly changing the
behaviour of the first command in a pipeline. Can't think of a good
test for that...


*** esh-proc.el.~1.21.~ 2008-05-20 16:28:53.000000000 -0700
--- esh-proc.el 2008-11-22 12:55:59.000000000 -0800
***************
*** 250,260 ****
      (cond
       ((fboundp 'start-process)
        (setq proc
            (apply 'start-process
                   (file-name-nondirectory command) nil
!                  ;; `start-process' can't deal with relative
!                  ;; filenames
!                  (append (list (expand-file-name command)) args)))
        (eshell-record-process-object proc)
        (set-process-buffer proc (current-buffer))
        (if (eshell-interactive-output-p)
--- 250,263 ----
      (cond
       ((fboundp 'start-process)
        (setq proc
+           ;; Bug#1388.  Some commands (eg bc) check isatty to decide
+           ;; whether they are being called interactively.
+           (let ((process-connection-type (unless eshell-in-pipeline-p
+                                            process-connection-type)))
              (apply 'start-process
                     (file-name-nondirectory command) nil
!                    ;; `start-process' can't deal with relative filenames
!                    (append (list (expand-file-name command)) args))))
        (eshell-record-process-object proc)
        (set-process-buffer proc (current-buffer))
        (if (eshell-interactive-output-p)