commit 661bfc3d0e1b7756db59d00d86e316f694cae3c6
Author: Christopher Faulet <cfaulet@haproxy.com>
Date:   Mon Jun 17 14:07:46 2019 +0200

    BUG/MINOR: mux-h1: Add the header connection in lower case in outgoing messages
    
    When necessary, this header is directly added in outgoing messages by the H1
    multiplexer. Because there is no HTX conversion first, the header name is not
    converserted to its lower case version. So, it must be added in lower case by
    the multiplexer.
    
    This patch must be backported to 2.0 and 1.9.
    
    (cherry picked from commit a110ecbd843e156dd01c6ac581c735be5e240d5b)
    Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/mux_h1.c b/src/mux_h1.c
index 317f1a55..21deb354 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -1642,7 +1642,7 @@ static size_t h1_process_output(struct h1c *h1c, struct buffer *buf, size_t coun
 					/* There is no "Connection:" header and
 					 * it the conn_mode must be
 					 * processed. So do it */
-					n = ist("Connection");
+					n = ist("connection");
 					v = ist("");
 					h1_process_output_conn_mode(h1s, h1m, &v);
 					if (v.len) {