Fix broken linking over IPv4 on IPv6 capable systems.

If no bind address was specified then one would be
created which had an incompatible address family to
the address that the server was trying to connect to.

1 files changed, 15 insertions, 5 deletions

diff --git a/src/modules/m_spanningtree/treesocket1.cpp b/src/modules/m_spanningtree/treesocket1.cpp
index fd20d04c4..1913fa4de 100644
--- a/src/modules/m_spanningtree/treesocket1.cpp
+++ b/src/modules/m_spanningtree/treesocket1.cpp
@@ -47,12 +47,22 @@ TreeSocket::TreeSocket(Link* link, Autoconnect* myac, const irc::sockets::sockad
 
 	irc::sockets::sockaddrs bind;
 	memset(&bind, 0, sizeof(bind));
-	if ((dest.family() == AF_INET || dest.family() == AF_INET6) && !irc::sockets::aptosa(link->Bind, 0, bind))
+	if (!link->Bind.empty() && (dest.family() == AF_INET || dest.family() == AF_INET6))
 	{
-		state = I_ERROR;
-		SetError("Bind address '" + link->Bind + "' is not an valid IPv4 or IPv6 address");
-		TreeSocket::OnError(I_ERR_BIND);
-		return;
+		if (!irc::sockets::aptosa(link->Bind, 0, bind))
+		{
+			state = I_ERROR;
+			SetError("Bind address '" + link->Bind + "' is not an valid IPv4 or IPv6 address");
+			TreeSocket::OnError(I_ERR_BIND);
+			return;
+		}
+		else if (bind.family() != dest.family())
+		{
+			state = I_ERROR;
+			SetError("Bind address '" + bind.addr() + "' is not the same address family as destination address '" + dest.addr() + "'");
+			TreeSocket::OnError(I_ERR_BIND);
+			return;
+		}
 	}
 
 	DoConnect(dest, bind, link->Timeout);