core: connectToIrc: Prevent DNS leaks on connection when using proxy

96fe7e713 introduced a call to QHostInfo::fromName() in order to avoid
problems related to the caching of DNS queries. It however is also called
when the user has specified that a proxy should be used. This behavior
therefore introduces a DNS leak.

This commit ensures that QHostInfo::fromName() is not called when
a proxy has been specified.

(cherry picked from commit 8aa70869402f71328d1a5f92fa36aa9579dc333b)

diff --git a/src/core/corenetwork.cpp b/src/core/corenetwork.cpp
index 0ebcd19..53960b6 100644 (file)
--- a/src/core/corenetwork.cpp
+++ b/src/core/corenetwork.cpp
@@ -218,8 +218,9 @@ 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.
 
     // 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.

-    QHostInfo::fromName(server.host);
-
+    if (! server.useProxy) {
+               QHostInfo::fromName(server.host);
+       }

 #ifdef HAVE_SSL
     if (server.useSsl) {
         CoreIdentity *identity = identityPtr();
 #ifdef HAVE_SSL
     if (server.useSsl) {
         CoreIdentity *identity = identityPtr();