From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 13 Jun 2016 16:44:40 +0000 (+0200)
Subject: Fix usage of std::distance() in DNSName::isPartOf()
X-Git-Tag: auth-4.0.0-rc1~14^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d8ec8f441d08511b76ece3215c73b952bc1f56db;p=thirdparty%2Fpdns.git

Fix usage of std::distance() in DNSName::isPartOf()
---

diff --git a/pdns/dnsname.cc b/pdns/dnsname.cc
index 1c81ea10f2..82bc2fe90e 100644
--- a/pdns/dnsname.cc
+++ b/pdns/dnsname.cc
@@ -200,8 +200,12 @@ bool DNSName::isPartOf(const DNSName& parent) const
     return false;
 
   // this is slightly complicated since we can't start from the end, since we can't see where a label begins/ends then
-  for(auto us=d_storage.cbegin(); us<d_storage.cend() && std::distance(us,d_storage.cend()) >= static_cast<unsigned int>(parent.d_storage.size()); us+=*us+1) {
-    if (std::distance(us,d_storage.cend()) == static_cast<unsigned int>(parent.d_storage.size())) {
+  for(auto us=d_storage.cbegin(); us<d_storage.cend(); us+=*us+1) {
+    auto distance = std::distance(us,d_storage.cend());
+    if (distance < 0 || static_cast<size_t>(distance) < parent.d_storage.size()) {
+      break;
+    }
+    if (static_cast<size_t>(distance) == parent.d_storage.size()) {
       auto p = parent.d_storage.cbegin();
       for(; us != d_storage.cend(); ++us, ++p) {
         if(dns2_tolower(*p) != dns2_tolower(*us))