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authorRichard M. Stallman <rms@gnu.org>1994-09-20 01:05:37 +0000
committerRichard M. Stallman <rms@gnu.org>1994-09-20 01:05:37 +0000
commitc44d2ceda94f66937c938dd35311aa3a8c7b7ae0 (patch)
tree259a60379eea182c74bbed2f70bdd5a6d27f404c /lispref
parent2a598462ecee6f6fd7ce5f14b095ff0247f7692d (diff)
downloademacs-c44d2ceda94f66937c938dd35311aa3a8c7b7ae0.tar.gz
*** empty log message ***
Diffstat (limited to 'lispref')
-rw-r--r--lispref/modes.texi18
1 files changed, 18 insertions, 0 deletions
diff --git a/lispref/modes.texi b/lispref/modes.texi
index fb71606f925..36c20ce8764 100644
--- a/lispref/modes.texi
+++ b/lispref/modes.texi
@@ -1381,3 +1381,21 @@ function goes at the end of the hook list and will be executed last.
@defun remove-hook hook function
This function removes @var{function} from the hook variable @var{hook}.
@end defun
+
+If you make a hook variable buffer-local, copy its value before you use
+@code{add-hook} or @code{remove-hook} to change it. For example,
+
+@example
+(defun my-major-mode ()
+ @dots{}
+ (make-local-variable 'foo-hook)
+ (if (boundp 'foo-hook)
+ (setq foo-hook (copy-sequence foo-hook)))
+ (add-hook 'foo-hook 'my-foo-function)"
+ @dots{}
+ )
+@end example
+
+Otherwise you may accidentally alter the list structure that forms part
+of the global value of the hook variable.
+