* subr.el (process-live-p): Return nil for non-process.

* progmodes/sh-script.el (sh-shell-process):
* progmodes/octave.el (inferior-octave-process-live-p):
* progmodes/gdb-mi.el (gdb-delchar-or-quit)
(gdb-inferior-io-sentinel):
* emacs-lock.el (emacs-lock-live-process-p): All uses changed.

Fixes: debbugs:16023

6 files changed, 22 insertions, 11 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b943b3c5fa8..df576658697 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,13 @@
+2013-12-02  Leo Liu  <sdl.web@gmail.com>
+
+        * subr.el (process-live-p): Return nil for non-process.  (Bug#16023)
+
+        * progmodes/sh-script.el (sh-shell-process):
+        * progmodes/octave.el (inferior-octave-process-live-p):
+        * progmodes/gdb-mi.el (gdb-delchar-or-quit)
+        (gdb-inferior-io-sentinel):
+        * emacs-lock.el (emacs-lock-live-process-p): All uses changed.
+
 2013-12-02  Dmitry Gutov  <dgutov@yandex.ru>
 
         * vc/log-edit.el (log-edit-kill-buffer): Move the use of
diff --git a/lisp/emacs-lock.el b/lisp/emacs-lock.el
index ac12c149b01..f1fa9316c82 100644
--- a/lisp/emacs-lock.el
+++ b/lisp/emacs-lock.el
@@ -109,8 +109,7 @@ Internal use only.")
 
 (defun emacs-lock-live-process-p (buffer-or-name)
   "Return t if BUFFER-OR-NAME is associated with a live process."
-  (let ((proc (get-buffer-process buffer-or-name)))
-    (and proc (process-live-p proc))))
+  (process-live-p (get-buffer-process buffer-or-name)))
 
 (defun emacs-lock--can-auto-unlock (action)
   "Return t if the current buffer can auto-unlock for ACTION.
diff --git a/lisp/progmodes/gdb-mi.el b/lisp/progmodes/gdb-mi.el
index 4b0a012e538..224def85895 100644
--- a/lisp/progmodes/gdb-mi.el
+++ b/lisp/progmodes/gdb-mi.el
@@ -981,7 +981,8 @@ no input, and GDB is waiting for input."
                (eq gud-minor-mode 'gdbmi))
     (error "Not in a GDB-MI buffer"))
   (let ((proc (get-buffer-process gud-comint-buffer)))
-    (if (and (eobp) proc (process-live-p proc)
+    (if (and (eobp)
+             (process-live-p proc)
              (not gud-running)
              (= (point) (marker-position (process-mark proc))))
         ;; Sending an EOF does not work with GDB-MI; submit an
@@ -1584,9 +1585,8 @@ this trigger is subscribed to `gdb-buf-publisher' and called with
     ;; read from the pty, and stops listening to it.  If the gdb
     ;; process is still running, remove the pty, make a new one, and
     ;; pass it to gdb.
-    (let ((gdb-proc (get-buffer-process gud-comint-buffer))
-          (io-buffer (process-buffer proc)))
-      (when (and gdb-proc (process-live-p gdb-proc)
+    (let ((io-buffer (process-buffer proc)))
+      (when (and (process-live-p (get-buffer-process gud-comint-buffer))
                  (buffer-live-p io-buffer))
         ;; `comint-exec' deletes the original process as a side effect.
         (comint-exec io-buffer "gdb-inferior" nil nil nil)
diff --git a/lisp/progmodes/octave.el b/lisp/progmodes/octave.el
index 5e79e6627d8..7b9d7c97f85 100644
--- a/lisp/progmodes/octave.el
+++ b/lisp/progmodes/octave.el
@@ -700,7 +700,7 @@ in the Inferior Octave buffer.")
 (declare-function compilation-forget-errors "compile" ())
 
 (defun inferior-octave-process-live-p ()
-  (and inferior-octave-process (process-live-p inferior-octave-process)))
+  (process-live-p inferior-octave-process))
 
 (define-derived-mode inferior-octave-mode comint-mode "Inferior Octave"
   "Major mode for interacting with an inferior Octave process."
diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 3ac0868414b..c270d433e76 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -1478,7 +1478,7 @@ frequently editing existing scripts with different styles.")
 (defun sh-shell-process (force)
   "Get a shell process for interaction.
 If FORCE is non-nil and no process found, create one."
-  (if (and sh-shell-process (process-live-p sh-shell-process))
+  (if (process-live-p sh-shell-process)
       sh-shell-process
     (setq sh-shell-process
           (let ((found nil) proc
diff --git a/lisp/subr.el b/lisp/subr.el
index b22c719f010..6b1e99f337c 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1885,9 +1885,11 @@ Signal an error if the program returns with a non-zero exit status."
 (defun process-live-p (process)
   "Returns non-nil if PROCESS is alive.
 A process is considered alive if its status is `run', `open',
-`listen', `connect' or `stop'."
-  (memq (process-status process)
-        '(run open listen connect stop)))
+`listen', `connect' or `stop'.  Value is nil if PROCESS is not a
+process."
+  (and (processp process)
+       (memq (process-status process)
+             '(run open listen connect stop))))
 
 ;; compatibility