That's because these variables are temporarily set to nil.\n\
As a result, a hook function cannot straightforwardly alter the value of\n\
these variables. See the Emacs Lisp manual for a way of\n\
-accomplishing an equivalent result by using other variables.");
+accomplishing an equivalent result by using other variables.\n\
+\n\
+If an unhandled error happens in running these functions,\n\
+the variable's value remains nil. That prevents the error\n\
+from happening repeatedly and making Emacs nonfunctional.");
Vbefore_change_functions = Qnil;
DEFVAR_LISP ("after-change-functions", &Vafter_change_functions,
That's because these variables are temporarily set to nil.\n\
As a result, a hook function cannot straightforwardly alter the value of\n\
these variables. See the Emacs Lisp manual for a way of\n\
-accomplishing an equivalent result by using other variables.");
-
+accomplishing an equivalent result by using other variables.\n\
+\n\
+If an unhandled error happens in running these functions,\n\
+the variable's value remains nil. That prevents the error\n\
+from happening repeatedly and making Emacs nonfunctional.");
Vafter_change_functions = Qnil;
DEFVAR_LISP ("first-change-hook", &Vfirst_change_hook,