Don't error if no GPG signing key configured

* lisp/gnus/mml-sec.el (mml-secure-epg-sign): Partially revert
"Make mml-secure-epg-sign bug out if we can't find an identity".
It causes signing to fail for people who have not set up
mml-secure-{smime,openpgp}-sign-with-sender, which is a regression
from Emacs-26 (Bug#40118).  In such a situation gpg will use its
default key.

Do not merge to master. On master Emacs will query the user.

diff --git a/lisp/gnus/mml-sec.el b/lisp/gnus/mml-sec.el
index 740e1d2b7227f5e62f4fc83da4d378d3c95166bc..8d77916e997e755e5ebac61f988a7e2284a88405 100644 (file)
--- a/lisp/gnus/mml-sec.el
+++ b/lisp/gnus/mml-sec.el
@@ -944,16 +944,6 @@ If no one is selected, symmetric encryption will be performed.  "
         (signer-names (mml-secure-signer-names protocol sender))
         (signers (mml-secure-signers context signer-names))
         signature micalg)
-    (unless signers
-      (let ((maybe-msg
-             (if mml-secure-smime-sign-with-sender
-                 "."
-               "; try setting `mml-secure-smime-sign-with-sender'.")))
-        ;; If `mml-secure-smime-sign-with-sender' is already non-nil
-        ;; then there's no point advising the user to examine it.  If
-        ;; there are any other variables worth examining, please
-        ;; improve this error message by having it mention them.
-        (error "Couldn't find any signer names%s" maybe-msg)))
     (when (eq 'OpenPGP protocol)
       (setf (epg-context-armor context) t)
       (setf (epg-context-textmode context) t)