# HG changeset patch
# User Kim Alvefur <zash@zash.se>
# Date 1618406473 -7200
# Node ID 83822be7704d0f515108d7c89bfa134130f3466e
# Parent  10d13e0554f91c6f8cf237e55ab315d7878251ad
util.xmppstream: Send <?xml?> declaration in same call as stream open

If network_settings.opportunistic_writes is enabled then this would
previously have resulted in two socket writes, and possibly two packets
being sent. This caused some issues in older versions of Gajim, which
apparently expected the stream opening in the first packet, and thus it
could not connect.

With this change and opportunistic_writes enabled, the first packet
should contain both the xml declaration and the stream open tag.
Without opportunistic_writes, there should be no observable change.

Tested with Gajim 1.1.2 (on same machine). Unsure if loopback behaves
differently than the network here.

diff -r 10d13e0554f9 -r 83822be7704d util/xmppstream.lua
--- a/util/xmppstream.lua	Tue Apr 06 23:25:15 2021 +0200
+++ b/util/xmppstream.lua	Wed Apr 14 15:21:13 2021 +0200
@@ -268,8 +268,7 @@
 		if session.stream_attrs then
 			session:stream_attrs(from, to, attr)
 		end
-		send("<?xml version='1.0'?>");
-		send(st.stanza("stream:stream", attr):top_tag());
+		send("<?xml version='1.0'?>"..st.stanza("stream:stream", attr):top_tag());
 		return true;
 	end