Emacs 21.3.50.1 (CVS sources) tex-mode bug

[Chip Coldwell <coldwell@frank.harvard.edu>]

I realize that I should expect problems if I choose to live on the
bleeding edge, but I figure I might as well report this problem just
in case the developers aren't already aware of it.

The problem is with Emacs 21.3.50.1 that I checked out from CVS
sources and compiled using the emacs/mac/make-package shell script on
the Macintosh OS X (10.3.7).  If I am editing in tex-mode and I run
the function 'tex-file' (by default bound to C-c C-f) emacs goes into
an infinite loop.  The loop is in the function tex-mode.el:tex-start-shell

(defun tex-start-shell ()
  (with-current-buffer
      (make-comint
       "tex-shell"
       (or tex-shell-file-name (getenv "ESHELL") shell-file-name)
       nil)
    (let ((proc (get-process "tex-shell")))
      (set-process-sentinel proc 'tex-shell-sentinel)
      (set-process-query-on-exit-flag proc nil)
      (tex-shell)
      (while (zerop (buffer-size))
	(sleep-for 1)))))

The function creates a shell using "make-comint", then waits for the
shell to start in the loop at the bottom.  Presumably, when the shell
has started, it will issue a prompt and the (buffer-size) procedure
will return non-zero and break out of the loop.  The problem is that
it never does.

I tried the following trivial program

(setq subshell (make-comint "subshell" "/bin/bash"))
(switch-to-buffer subshell)

And it does indeed create a subshell in a buffer, but the shell never
issues a prompt string.  Setting the PS1 environment variable has no
effect in this buffer, for reasons I haven't figured out yet.

Chip

-- 
Charles M. "Chip" Coldwell
"Turn on, log in, tune out"