+(defun custom-add-dependencies (symbol value)
+ "To the custom option SYMBOL, add dependencies specified by VALUE.
+VALUE should be a list of symbols. For each symbol in that list,
+this specifies that SYMBOL should be set after the specified symbol, if
+both appear in constructs like `custom-set-variables'."
+ (unless (listp value)
+ (error "Invalid custom dependency `%s'" value))
+ (let* ((deps (get symbol 'custom-dependencies))
+ (new-deps deps))
+ (while value
+ (let ((dep (car value)))
+ (unless (symbolp dep)
+ (error "Invalid custom dependency `%s'" dep))
+ (unless (memq dep new-deps)
+ (setq new-deps (cons dep new-deps)))
+ (setq value (cdr value))))
+ (unless (eq deps new-deps)
+ (put symbol 'custom-dependencies new-deps))))
+