Fix spell-checking email message with citations

This became broken 7 years ago, when the 'boundp condition was
removed, and with it an important unrelated part of the code.
* lisp/textmodes/ispell.el (ispell-message): Fix cite-regexp.

1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/textmodes/ispell.el b/lisp/textmodes/ispell.el
index eb550b639a3..48d48b07937 100644
--- a/lisp/textmodes/ispell.el
+++ b/lisp/textmodes/ispell.el
@@ -3973,7 +3973,8 @@ You can bind this to the key C-c i in GNUS or mail by adding to
                        (point-max)))
                     (t (min (point-max) (funcall ispell-message-text-end))))))
            (default-prefix   ; Vanilla cite prefix (just used for cite-regexp)
-             (if (ispell-non-empty-string mail-yank-prefix)
+             (if mail-yank-prefix
+                 (ispell-non-empty-string mail-yank-prefix)
                "   \\|\t"))
            (cite-regexp                 ;Prefix of quoted text
             (cond