# HG changeset patch
# User Kim Alvefur <zash@zash.se>
# Date 1623880380 -7200
# Node ID 6dcc45a2e3bc32216c4192abe9b4149bf5a43a6c
# Parent  b2610460d9ab91ffb881e24bd6c9edd6d5f8b141
mod_s2s: Bail if connection is destroyed after attempting to open stream

Fixes "attempt to compare number with nil" because `session.version` has
been cleared by s2smanager.destroy_session.

This can happen with the server_epoll setting opportunistic_writes
enabled, which means that it can notice that the connection failed at
this point, after which it triggers the whole chain of events that leads
to session destruction and "cleaning" most of the session fields.

diff -r b2610460d9ab -r 6dcc45a2e3bc plugins/mod_s2s.lua
--- a/plugins/mod_s2s.lua	Wed Jun 16 00:00:17 2021 +0200
+++ b/plugins/mod_s2s.lua	Wed Jun 16 23:53:00 2021 +0200
@@ -461,6 +461,11 @@
 		end
 
 		session:open_stream(session.to_host, session.from_host)
+		if session.destroyed then
+			-- sending the stream opening could have failed during an opportunistic write
+			return
+		end
+
 		session.notopen = nil;
 		if session.version >= 1.0 then
 			local features = st.stanza("stream:features");