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diff --git a/lisp/abbrev.el b/lisp/abbrev.el
index 5b4ffe3ae8f63722edb1701013af8ab12ef5e6ba..9092be584f4619072baa91c42c3284aa406117fc 100644 (file)
--- a/lisp/abbrev.el
+++ b/lisp/abbrev.el
@@ -522,6 +522,7 @@ the current abbrev table before abbrev lookup happens."
       (setplist newsym (symbol-plist sym)))
     (abbrev-table-put table :abbrev-table-modiff
                       (1+ (abbrev-table-get table :abbrev-table-modiff))))
+  ;; For backward compatibility, always return nil.
   nil)
 
 (defun define-abbrev (table name expansion &optional hook &rest props)