(tex-send-command): Give meaningful error message.

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 3a28ea73e0e7cd8cd3e4848d0bddab4c4f53ddb9..427583a88f86f6a85f0a29d1e5d9b7dbec643ec7 100644 (file)
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -883,7 +883,7 @@ substitution will be made in COMMAND.  COMMAND can be any expression that
 evaluates to a command string."
   (save-excursion
     (let* ((cmd (eval command))
-          (proc (get-process "tex-shell"))
+          (proc (or (get-process "tex-shell") (error "No TeX subprocess")))
           (buf (process-buffer proc))
            (star (string-match "\\*" cmd))
           (string