http_proxy: fix the User-Agent inclusion in CONNECT

It should not refer to the uagent string that is allocated and created
for the end server http request, as that pointer may be cleared on
subsequent CONNECT requests.

Added test case 1184 to verify.

Reported-by: T200proX7 on github
Fixes #7705

1 files changed, 10 insertions, 15 deletions

diff --git a/lib/http_proxy.c b/lib/http_proxy.c
index c4fba9d06..fe63b8c15 100644
--- a/lib/http_proxy.c
+++ b/lib/http_proxy.c
@@ -300,32 +300,27 @@ static CURLcode CONNECT(struct Curl_easy *data,
                                      hostheader, TRUE);
 
       if(!result) {
-        const char *proxyconn = "";
-        const char *useragent = "";
         const char *httpv =
           (conn->http_proxy.proxytype == CURLPROXY_HTTP_1_0) ? "1.0" : "1.1";
 
-        if(!Curl_checkProxyheaders(data, conn, "Proxy-Connection"))
-          proxyconn = "Proxy-Connection: Keep-Alive\r\n";
-
-        if(!Curl_checkProxyheaders(data, conn, "User-Agent") &&
-           data->set.str[STRING_USERAGENT])
-          useragent = data->state.aptr.uagent;
-
         result =
           Curl_dyn_addf(req,
                         "CONNECT %s HTTP/%s\r\n"
                         "%s"  /* Host: */
-                        "%s"  /* Proxy-Authorization */
-                        "%s"  /* User-Agent */
-                        "%s", /* Proxy-Connection */
+                        "%s", /* Proxy-Authorization */
                         hostheader,
                         httpv,
                         host?host:"",
                         data->state.aptr.proxyuserpwd?
-                        data->state.aptr.proxyuserpwd:"",
-                        useragent,
-                        proxyconn);
+                        data->state.aptr.proxyuserpwd:"");
+
+        if(!result && !Curl_checkProxyheaders(data, conn, "User-Agent") &&
+           data->set.str[STRING_USERAGENT])
+          result = Curl_dyn_addf(req, "User-Agent: %s\r\n",
+                                 data->set.str[STRING_USERAGENT]);
+
+        if(!result && !Curl_checkProxyheaders(data, conn, "Proxy-Connection"))
+          result = Curl_dyn_add(req, "Proxy-Connection: Keep-Alive\r\n");
 
         if(!result)
           result = Curl_add_custom_headers(data, TRUE, req);