From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 25 Mar 2021 12:13:18 +0000 (+0100)
Subject: multi: close the connection when h2=>h1 downgrading
X-Git-Tag: curl-7_76_0~23
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7b6bfd2d78cfead3f1dfadbcedc92e4fbb24ff7c;p=thirdparty%2Fcurl.git

multi: close the connection when h2=>h1 downgrading

Otherwise libcurl is likely to reuse the connection again in the next
attempt since the connection reuse logic doesn't take downgrades into
account.

Reported-by: Anthony Ramine
Fixes #6788
Closes #6793
---

diff --git a/lib/multi.c b/lib/multi.c
index f5bacc17cb..5de4793225 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -2158,6 +2158,7 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
 
         if(!ret) {
           infof(data, "Downgrades to HTTP/1.1!\n");
+          connclose(data->conn, "Disconnect HTTP/2 for HTTP/1");
           data->state.httpwant = CURL_HTTP_VERSION_1_1;
           /* clear the error message bit too as we ignore the one we got */
           data->state.errorbuf = FALSE;