commit 33a73bfa0712c483830e4c9abbf4d6a0551478bf
author Lorenzo Colitti <lorenzo@google.com> Mon Sep 08 18:09:43 2014 +0900
committer Lorenzo Colitti <lorenzo@google.com> Thu Sep 11 08:36:12 2014 +0900
tree 6815d14d87bd78ee3d443f53f60ed42d7d8d3201
parent 7efad83d430f4d824f2aaa75edea5106f6ff8aae

When comparing DNS server configs, also compare number of servers

Bug: 16070602
Change-Id: I605f1cca50b08479ebcad290b3bd179f59be8a96

libc/dns/resolv/res_cache.c

diff --git a/libc/dns/resolv/res_cache.c b/libc/dns/resolv/res_cache.c
index 419b748..d68ec3b 100644
--- a/libc/dns/resolv/res_cache.c
+++ b/libc/dns/resolv/res_cache.c
@@ -1999,10 +1999,25 @@
 {
     int i;
     char** ns;
+    int currentservers;
     int equal = 1;
 
-    // compare each name server against current name servers
     if (numservers > MAXNS) numservers = MAXNS;
+
+    // Find out how many nameservers we had before.
+    currentservers = 0;
+    for (ns = cache_info->nameservers; *ns; ns++)
+        currentservers++;
+
+    if (currentservers != numservers)
+        return 0;
+
+    // Compare each name server against current name servers.
+    // TODO: this is incorrect if the list of current or previous nameservers
+    // contains duplicates. This does not really matter because the framework
+    // filters out duplicates, but we should probably fix it. It's also
+    // insensitive to the order of the nameservers; we should probably fix that
+    // too.
     for (i = 0; i < numservers && equal; i++) {
         ns = cache_info->nameservers;
         equal = 0;