(remove-hook): New function, analogous to add-hook. This

is now the recommended way to remove a hook that you have added.

1 files changed, 15 insertions, 0 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index aa158175998..02ada23bb67 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -493,6 +493,21 @@ function, it is changed to a list of functions."
                (nconc (symbol-value hook) (list function))
              (cons function (symbol-value hook))))))
 
+(defun remove-hook (hook function)
+  "Remove from the value of HOOK the function FUNCTION.
+HOOK should be a symbol, and FUNCTION may be any valid function.  If
+FUNCTION isn't the value of HOOK, or, if FUNCTION doesn't appear in the
+list of hooks to run in HOOK, then nothing is done.  See add-hook."
+  (if (or (not (boundp hook))           ;unbound symbol, or
+          (null (symbol-value hook))    ;value is nil, or
+          (null function))              ;function is nil, then
+      nil                               ;Do nothing.
+    (let ((hook-value (symbol-value hook)))
+      (if (consp hook-value)
+          (setq hook-value (delete function hook-value))
+        (if (eq hook-value function)
+            (setq hook-value nil)))
+      (set hook hook-value))))
 
 ;;;; Specifying things to do after certain files are loaded.