UTF8: Avoid treating a punycoded dns lookup as an implicit redirection

[exim.git] / src / src / dns.c

diff --git a/src/src/dns.c b/src/src/dns.c
index 6f75386ed528c23236b2953584de4c4247e127b2..a9970d9fe571addfbd95d09e9ed096264be0b2e8 100644 (file)
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -581,6 +581,8 @@ if (previous != NULL)
   {
   uschar * alabel;
   uschar * errstr = NULL;
+  DEBUG(D_dns) if (string_is_utf8(name))
+    debug_printf("convert utf8 '%s' to alabel for for lookup\n", name);
   if ((alabel = string_domain_utf8_to_alabel(name, &errstr)), errstr)
     {
     DEBUG(D_dns)
@@ -738,7 +740,8 @@ won't return any.
 If fully_qualified_name is not NULL, set it to point to the full name
 returned by the resolver, if this is different to what it is given, unless
 the returned name starts with "*" as some nameservers seem to be returning
-wildcards in this form.
+wildcards in this form.  In international mode "different" means "alabel
+forms are different".
 
 Arguments:
   dnsa                  pointer to dns_answer structure
@@ -799,18 +802,19 @@ for (i = 0; i < 10; i++)
 
   if (i == 0 && fully_qualified_name != NULL)
     {
-    if (cname_rr.data != NULL)
-      {
-      if (Ustrcmp(cname_rr.name, *fully_qualified_name) != 0 &&
-          cname_rr.name[0] != '*')
-        *fully_qualified_name = string_copy_dnsdomain(cname_rr.name);
-      }
-    else if (type_rr.data != NULL)
-      {
-      if (Ustrcmp(type_rr.name, *fully_qualified_name) != 0 &&
-          type_rr.name[0] != '*')
-        *fully_qualified_name = string_copy_dnsdomain(type_rr.name);
-      }
+    uschar * rr_name = cname_rr.data ? cname_rr.name
+      : type_rr.data ? type_rr.name : NULL;
+    if (  rr_name
+       && Ustrcmp(rr_name, *fully_qualified_name) != 0
+       && rr_name[0] != '*'
+#ifdef EXPERIMENTAL_INTERNATIONAL
+       && (  !string_is_utf8(*fully_qualified_name)
+         || Ustrcmp(rr_name,
+              string_domain_utf8_to_alabel(*fully_qualified_name, NULL)) != 0
+         )
+#endif
+       )
+        *fully_qualified_name = string_copy_dnsdomain(rr_name);
     }
 
   /* If any data records of the correct type were found, we are done. */