spam.m4: Check that non-userv spam thresholds are well-formed.

Both are untrustworthy sources.

diff --git a/spam.m4 b/spam.m4
index e480880..57b0c27 100644 (file)
--- a/spam.m4
+++ b/spam.m4
@@ -50,7 +50,9 @@ fetch_spam_limit:
                                        @$domain/\
                                        $sender_address} \
                               nwildlsearch {CONF_userconf_dir/spam-limit} \
-                              {spam_limit=$value} \
+                              {${if match{$value}{\N^[0-9]+$\N} \
+                                    {spam_limit=$value} \
+                                    {}}} \
                               {}}} \
                     {}} \
                ${if exists {CONF_userconf_dir/spam-limit.userv} \