(enable-flow-control): Fix bugs turning off flow ctrl.

1 files changed, 8 insertions, 4 deletions

diff --git a/lisp/flow-ctrl.el b/lisp/flow-ctrl.el
index f871493c0a2..e2cef00684b 100644
--- a/lisp/flow-ctrl.el
+++ b/lisp/flow-ctrl.el
@@ -62,10 +62,14 @@ With arg, enable flow control mode if arg is positive, otherwise disable."
       (progn
         ;; Turn flow control off, and stop exchanging chars.
         (set-input-mode t nil (nth 2 (current-input-mode)))
-        (aset keyboard-translate-table flow-control-c-s-replacement nil)
-        (aset keyboard-translate-table ?\^s nil)
-        (aset keyboard-translate-table flow-control-c-q-replacement nil)
-        (aset keyboard-translate-table ?\^q nil))
+        (if keyboard-translate-table
+            (progn
+              (aset keyboard-translate-table flow-control-c-s-replacement
+                    flow-control-c-s-replacement)
+              (aset keyboard-translate-table ?\^s ?\^s)
+              (aset keyboard-translate-table flow-control-c-q-replacement
+                    flow-control-c-q-replacement)
+              (aset keyboard-translate-table ?\^q ?\^q))))
     ;; Turn flow control on.
     ;; Tell emacs to pass C-s and C-q to OS.
     (set-input-mode nil t (nth 2 (current-input-mode)))