Race condition in eshell-gather-process-output

["Jürgen Hötzel" <juergen@archlinux.org>]

Hi,

I stumbled across this while debugging eshell/tramp external commands:

In eshell-gather-process-output the external process is started using
start-file-process:

      (setq proc
	    (let ((process-connection-type
		   (unless (eshell-needs-pipe-p command)
		     process-connection-type))
		  (command (or (file-remote-p command 'localname) command)))
	      (apply 'start-file-process
		     (file-name-nondirectory command) nil
		     ;; `start-process' can't deal with relative filenames.
		     (append (list (expand-file-name command)) args))))
----------------------------------------------------------------------------------------
something can happen meanwhile: The process may have written
output (nil output buffer)
----------------------------------------------------------------------------------------

      (eshell-record-process-object proc)
      (set-process-buffer proc (current-buffer))

^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Maybe too late to set output buffer!

Why is the output buffer not set directly:

(apply 'start-file-process
		     (file-name-nondirectory command) (current-buffer)
		     ...)

Regards,

Jürgen