Avoid errors in 'rmail-get-new-mail'

* lisp/mail/rmail.el (rmail-insert-inbox-text): Don't assume
the Rmail protocol is always a string when calling
'rmail-remote-proto-p'.  (Bug#34252)

1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 768454ab13b..8a75f1fba91 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -2079,7 +2079,8 @@ Value is the size of the newly read mail after conversion."
                    ;; If we just read the password, most likely it is
                    ;; wrong.  Otherwise, see if there is a specific
                    ;; reason to think that the problem is a wrong passwd.
-                   (if (and (rmail-remote-proto-p proto)
+                   (if (and proto
+                            (rmail-remote-proto-p proto)
                             (or got-password
                                 (re-search-forward rmail-remote-password-error
                                                    nil t)))