+59. Two changes related to the smtp_active_hostname option:
+
+ (1) $smtp_active_hostname is now available as a variable.
+ (2) The default for smtp_banner uses $smtp_active_hostname instead
+ of $primary_hostname.
+
+60. The host_aton() function is supposed to be passed a string that is known
+ to be a valid IP address. However, in the case of IPv6 addresses, it was
+ not checking this. This is a hostage to fortune. Exim now panics and dies
+ if the condition is not met. A case was found where this could be provoked
+ from a dnsdb lookup; fortuitously, this particular loophole had already
+ been fixed by change 4.50/55 above. If there are any other similar
+ loopholes, the new check should stop them being exploited.
+