X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=src%2Fsrc%2Fdns.c;h=b567c3e71813b87fdfdf5667e8c8a32a2f73f8b2;hb=824ac9569a44ae411785f7ba2014d243e85b992d;hp=d036162cb873b44a10f7a9927174411fd90a88da;hpb=eb24befc3e9ad0a36ef8f0bc3527a9bc6c923a7b;p=exim.git

diff --git a/src/src/dns.c b/src/src/dns.c
index d036162cb..b567c3e71 100644
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -3,6 +3,7 @@
 *************************************************/
 
 /* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for interfacing with the DNS. */
@@ -501,6 +502,8 @@ const uschar * auth_name;
 const uschar * trusted;
 
 if (dnsa->answerlen < 0) return FALSE;
+/* Beware that newer versions of glibc on Linux will filter out the ad bit
+unless their shiny new RES_TRUSTAD bit is set for the resolver.  */
 if (h->ad) return TRUE;
 
 /* If the resolver we ask is authoritative for the domain in question, it may