From 0936ecd0ee5e3e28c098fefc9e2c0e6847cb7a82 Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Tue, 5 Jan 2021 14:30:21 +0100
Subject: [PATCH] pretransfer: setup the User-Agent header here

... and not in the connection setup, as for multiplexed transfers the
connection setup might be skipped and then the transfer would end up
without the set user-agent!

Reported-by: Flameborn on github
Assisted-by: Andrey Gursky
Assisted-by: Jay Satiro
Assisted-by: Mike Gelfand
Fixes #6312
Closes #6417
---
 lib/transfer.c | 14 ++++++++++++++
 lib/url.c      | 14 --------------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/transfer.c b/lib/transfer.c
index 7b5a0516d..baf305fe1 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -1495,6 +1495,20 @@ CURLcode Curl_pretransfer(struct Curl_easy *data)
     Curl_hsts_loadcb(data, data->hsts);
   }
 
+  /*
+   * Set user-agent. Used for HTTP, but since we can attempt to tunnel
+   * basically anything through a http proxy we can't limit this based on
+   * protocol.
+   */
+  if(data->set.str[STRING_USERAGENT]) {
+    Curl_safefree(data->state.aptr.uagent);
+    data->state.aptr.uagent =
+      aprintf("User-Agent: %s\r\n", data->set.str[STRING_USERAGENT]);
+    if(!data->state.aptr.uagent)
+      return CURLE_OUT_OF_MEMORY;
+  }
+
+  data->req.headerbytecount = 0;
   return result;
 }
 
diff --git a/lib/url.c b/lib/url.c
index 45577713e..60ba56dae 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -3942,20 +3942,6 @@ CURLcode Curl_setup_conn(struct connectdata *conn,
      lingering set from a previous invoke */
   conn->bits.proxy_connect_closed = FALSE;
 #endif
-  /*
-   * Set user-agent. Used for HTTP, but since we can attempt to tunnel
-   * basically anything through a http proxy we can't limit this based on
-   * protocol.
-   */
-  if(data->set.str[STRING_USERAGENT]) {
-    Curl_safefree(data->state.aptr.uagent);
-    data->state.aptr.uagent =
-      aprintf("User-Agent: %s\r\n", data->set.str[STRING_USERAGENT]);
-    if(!data->state.aptr.uagent)
-      return CURLE_OUT_OF_MEMORY;
-  }
-
-  data->req.headerbytecount = 0;
 
 #ifdef CURL_DO_LINEEND_CONV
   data->state.crlf_conversions = 0; /* reset CRLF conversion counter */