core: connectToIrc: Add clarifying comment on DNS lookups

Closes GH-298.

(cherry picked from commit a6c3d4252d760a6de70cb000cc3d6ee34a36eb31)

diff --git a/src/core/corenetwork.cpp b/src/core/corenetwork.cpp
index 53960b6..ca75c2e 100644 (file)
--- a/src/core/corenetwork.cpp
+++ b/src/core/corenetwork.cpp
@@ -219,8 +219,10 @@ void CoreNetwork::connectToIrc(bool reconnecting)
     // Qt caches DNS entries for a minute, resulting in round-robin (e.g. for chat.freenode.net) not working if several users
     // connect at a similar time. QHostInfo::fromName(), however, always performs a fresh lookup, overwriting the cache entry.
     if (! server.useProxy) {
-               QHostInfo::fromName(server.host);
-       }
+        //Avoid hostname lookups when a proxy is specified. The lookups won't use the proxy and may therefore leak the DNS
+        //hostname of the server. Qt's DNS cache also isn't used by the proxy so we don't need to refresh the entry.
+        QHostInfo::fromName(server.host);
+    }
 #ifdef HAVE_SSL
     if (server.useSsl) {
         CoreIdentity *identity = identityPtr();