--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/http.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,4162 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifndef CURL_DISABLE_HTTP
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NET_IF_H
+#include <net/if.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+
+#include "urldata.h"
+#include <curl/curl.h>
+#include "transfer.h"
+#include "sendf.h"
+#include "formdata.h"
+#include "mime.h"
+#include "progress.h"
+#include "curl_base64.h"
+#include "cookie.h"
+#include "vauth/vauth.h"
+#include "vtls/vtls.h"
+#include "http_digest.h"
+#include "http_ntlm.h"
+#include "curl_ntlm_wb.h"
+#include "http_negotiate.h"
+#include "url.h"
+#include "share.h"
+#include "hostip.h"
+#include "http.h"
+#include "select.h"
+#include "parsedate.h" /* for the week day and month names */
+#include "strtoofft.h"
+#include "multiif.h"
+#include "strcase.h"
+#include "content_encoding.h"
+#include "http_proxy.h"
+#include "warnless.h"
+#include "non-ascii.h"
+#include "http2.h"
+#include "connect.h"
+#include "strdup.h"
+#include "altsvc.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * Forward declarations.
+ */
+
+static int http_getsock_do(struct connectdata *conn,
+                           curl_socket_t *socks);
+static int http_should_fail(struct connectdata *conn);
+
+#ifndef CURL_DISABLE_PROXY
+static CURLcode add_haproxy_protocol_header(struct connectdata *conn);
+#endif
+
+#ifdef USE_SSL
+static CURLcode https_connecting(struct connectdata *conn, bool *done);
+static int https_getsock(struct connectdata *conn,
+                         curl_socket_t *socks);
+#else
+#define https_connecting(x,y) CURLE_COULDNT_CONNECT
+#endif
+static CURLcode http_setup_conn(struct connectdata *conn);
+
+/*
+ * HTTP handler interface.
+ */
+const struct Curl_handler Curl_handler_http = {
+  "HTTP",                               /* scheme */
+  http_setup_conn,                      /* setup_connection */
+  Curl_http,                            /* do_it */
+  Curl_http_done,                       /* done */
+  ZERO_NULL,                            /* do_more */
+  Curl_http_connect,                    /* connect_it */
+  ZERO_NULL,                            /* connecting */
+  ZERO_NULL,                            /* doing */
+  ZERO_NULL,                            /* proto_getsock */
+  http_getsock_do,                      /* doing_getsock */
+  ZERO_NULL,                            /* domore_getsock */
+  ZERO_NULL,                            /* perform_getsock */
+  ZERO_NULL,                            /* disconnect */
+  ZERO_NULL,                            /* readwrite */
+  ZERO_NULL,                            /* connection_check */
+  PORT_HTTP,                            /* defport */
+  CURLPROTO_HTTP,                       /* protocol */
+  PROTOPT_CREDSPERREQUEST               /* flags */
+};
+
+#ifdef USE_SSL
+/*
+ * HTTPS handler interface.
+ */
+const struct Curl_handler Curl_handler_https = {
+  "HTTPS",                              /* scheme */
+  http_setup_conn,                      /* setup_connection */
+  Curl_http,                            /* do_it */
+  Curl_http_done,                       /* done */
+  ZERO_NULL,                            /* do_more */
+  Curl_http_connect,                    /* connect_it */
+  https_connecting,                     /* connecting */
+  ZERO_NULL,                            /* doing */
+  https_getsock,                        /* proto_getsock */
+  http_getsock_do,                      /* doing_getsock */
+  ZERO_NULL,                            /* domore_getsock */
+  ZERO_NULL,                            /* perform_getsock */
+  ZERO_NULL,                            /* disconnect */
+  ZERO_NULL,                            /* readwrite */
+  ZERO_NULL,                            /* connection_check */
+  PORT_HTTPS,                           /* defport */
+  CURLPROTO_HTTPS,                      /* protocol */
+  PROTOPT_SSL | PROTOPT_CREDSPERREQUEST | PROTOPT_ALPN_NPN /* flags */
+};
+#endif
+
+static CURLcode http_setup_conn(struct connectdata *conn)
+{
+  /* allocate the HTTP-specific struct for the Curl_easy, only to survive
+     during this request */
+  struct HTTP *http;
+  struct Curl_easy *data = conn->data;
+  DEBUGASSERT(data->req.protop == NULL);
+
+  http = calloc(1, sizeof(struct HTTP));
+  if(!http)
+    return CURLE_OUT_OF_MEMORY;
+
+  Curl_mime_initpart(&http->form, conn->data);
+  data->req.protop = http;
+
+  if(data->set.httpversion == CURL_HTTP_VERSION_3) {
+    if(conn->handler->flags & PROTOPT_SSL)
+      /* Only go HTTP/3 directly on HTTPS URLs. It needs a UDP socket and does
+         the QUIC dance. */
+      conn->transport = TRNSPRT_QUIC;
+    else {
+      failf(data, "HTTP/3 requested for non-HTTPS URL");
+      return CURLE_URL_MALFORMAT;
+    }
+  }
+  else {
+    if(!CONN_INUSE(conn))
+      /* if not already multi-using, setup connection details */
+      Curl_http2_setup_conn(conn);
+    Curl_http2_setup_req(data);
+  }
+  return CURLE_OK;
+}
+
+#ifndef CURL_DISABLE_PROXY
+/*
+ * checkProxyHeaders() checks the linked list of custom proxy headers
+ * if proxy headers are not available, then it will lookup into http header
+ * link list
+ *
+ * It takes a connectdata struct as input instead of the Curl_easy simply to
+ * know if this is a proxy request or not, as it then might check a different
+ * header list. Provide the header prefix without colon!.
+ */
+char *Curl_checkProxyheaders(const struct connectdata *conn,
+                             const char *thisheader)
+{
+  struct curl_slist *head;
+  size_t thislen = strlen(thisheader);
+  struct Curl_easy *data = conn->data;
+
+  for(head = (conn->bits.proxy && data->set.sep_headers) ?
+        data->set.proxyheaders : data->set.headers;
+      head; head = head->next) {
+    if(strncasecompare(head->data, thisheader, thislen) &&
+       Curl_headersep(head->data[thislen]))
+      return head->data;
+  }
+
+  return NULL;
+}
+#else
+/* disabled */
+#define Curl_checkProxyheaders(x,y) NULL
+#endif
+
+/*
+ * Strip off leading and trailing whitespace from the value in the
+ * given HTTP header line and return a strdupped copy. Returns NULL in
+ * case of allocation failure. Returns an empty string if the header value
+ * consists entirely of whitespace.
+ */
+char *Curl_copy_header_value(const char *header)
+{
+  const char *start;
+  const char *end;
+  char *value;
+  size_t len;
+
+  /* Find the end of the header name */
+  while(*header && (*header != ':'))
+    ++header;
+
+  if(*header)
+    /* Skip over colon */
+    ++header;
+
+  /* Find the first non-space letter */
+  start = header;
+  while(*start && ISSPACE(*start))
+    start++;
+
+  /* data is in the host encoding so
+     use '\r' and '\n' instead of 0x0d and 0x0a */
+  end = strchr(start, '\r');
+  if(!end)
+    end = strchr(start, '\n');
+  if(!end)
+    end = strchr(start, '\0');
+  if(!end)
+    return NULL;
+
+  /* skip all trailing space letters */
+  while((end > start) && ISSPACE(*end))
+    end--;
+
+  /* get length of the type */
+  len = end - start + 1;
+
+  value = malloc(len + 1);
+  if(!value)
+    return NULL;
+
+  memcpy(value, start, len);
+  value[len] = 0; /* zero terminate */
+
+  return value;
+}
+
+#ifndef CURL_DISABLE_HTTP_AUTH
+/*
+ * http_output_basic() sets up an Authorization: header (or the proxy version)
+ * for HTTP Basic authentication.
+ *
+ * Returns CURLcode.
+ */
+static CURLcode http_output_basic(struct connectdata *conn, bool proxy)
+{
+  size_t size = 0;
+  char *authorization = NULL;
+  struct Curl_easy *data = conn->data;
+  char **userp;
+  const char *user;
+  const char *pwd;
+  CURLcode result;
+  char *out;
+
+  if(proxy) {
+    userp = &conn->allocptr.proxyuserpwd;
+    user = conn->http_proxy.user;
+    pwd = conn->http_proxy.passwd;
+  }
+  else {
+    userp = &conn->allocptr.userpwd;
+    user = conn->user;
+    pwd = conn->passwd;
+  }
+
+  out = aprintf("%s:%s", user, pwd);
+  if(!out)
+    return CURLE_OUT_OF_MEMORY;
+
+  result = Curl_base64_encode(data, out, strlen(out), &authorization, &size);
+  if(result)
+    goto fail;
+
+  if(!authorization) {
+    result = CURLE_REMOTE_ACCESS_DENIED;
+    goto fail;
+  }
+
+  free(*userp);
+  *userp = aprintf("%sAuthorization: Basic %s\r\n",
+                   proxy ? "Proxy-" : "",
+                   authorization);
+  free(authorization);
+  if(!*userp) {
+    result = CURLE_OUT_OF_MEMORY;
+    goto fail;
+  }
+
+  fail:
+  free(out);
+  return result;
+}
+
+/*
+ * http_output_bearer() sets up an Authorization: header
+ * for HTTP Bearer authentication.
+ *
+ * Returns CURLcode.
+ */
+static CURLcode http_output_bearer(struct connectdata *conn)
+{
+  char **userp;
+  CURLcode result = CURLE_OK;
+
+  userp = &conn->allocptr.userpwd;
+  free(*userp);
+  *userp = aprintf("Authorization: Bearer %s\r\n",
+                   conn->oauth_bearer);
+
+  if(!*userp) {
+    result = CURLE_OUT_OF_MEMORY;
+    goto fail;
+  }
+
+  fail:
+  return result;
+}
+
+#endif
+
+/* pickoneauth() selects the most favourable authentication method from the
+ * ones available and the ones we want.
+ *
+ * return TRUE if one was picked
+ */
+static bool pickoneauth(struct auth *pick, unsigned long mask)
+{
+  bool picked;
+  /* only deal with authentication we want */
+  unsigned long avail = pick->avail & pick->want & mask;
+  picked = TRUE;
+
+  /* The order of these checks is highly relevant, as this will be the order
+     of preference in case of the existence of multiple accepted types. */
+  if(avail & CURLAUTH_NEGOTIATE)
+    pick->picked = CURLAUTH_NEGOTIATE;
+  else if(avail & CURLAUTH_BEARER)
+    pick->picked = CURLAUTH_BEARER;
+  else if(avail & CURLAUTH_DIGEST)
+    pick->picked = CURLAUTH_DIGEST;
+  else if(avail & CURLAUTH_NTLM)
+    pick->picked = CURLAUTH_NTLM;
+  else if(avail & CURLAUTH_NTLM_WB)
+    pick->picked = CURLAUTH_NTLM_WB;
+  else if(avail & CURLAUTH_BASIC)
+    pick->picked = CURLAUTH_BASIC;
+  else {
+    pick->picked = CURLAUTH_PICKNONE; /* we select to use nothing */
+    picked = FALSE;
+  }
+  pick->avail = CURLAUTH_NONE; /* clear it here */
+
+  return picked;
+}
+
+/*
+ * http_perhapsrewind()
+ *
+ * If we are doing POST or PUT {
+ *   If we have more data to send {
+ *     If we are doing NTLM {
+ *       Keep sending since we must not disconnect
+ *     }
+ *     else {
+ *       If there is more than just a little data left to send, close
+ *       the current connection by force.
+ *     }
+ *   }
+ *   If we have sent any data {
+ *     If we don't have track of all the data {
+ *       call app to tell it to rewind
+ *     }
+ *     else {
+ *       rewind internally so that the operation can restart fine
+ *     }
+ *   }
+ * }
+ */
+static CURLcode http_perhapsrewind(struct connectdata *conn)
+{
+  struct Curl_easy *data = conn->data;
+  struct HTTP *http = data->req.protop;
+  curl_off_t bytessent;
+  curl_off_t expectsend = -1; /* default is unknown */
+
+  if(!http)
+    /* If this is still NULL, we have not reach very far and we can safely
+       skip this rewinding stuff */
+    return CURLE_OK;
+
+  switch(data->set.httpreq) {
+  case HTTPREQ_GET:
+  case HTTPREQ_HEAD:
+    return CURLE_OK;
+  default:
+    break;
+  }
+
+  bytessent = data->req.writebytecount;
+
+  if(conn->bits.authneg) {
+    /* This is a state where we are known to be negotiating and we don't send
+       any data then. */
+    expectsend = 0;
+  }
+  else if(!conn->bits.protoconnstart) {
+    /* HTTP CONNECT in progress: there is no body */
+    expectsend = 0;
+  }
+  else {
+    /* figure out how much data we are expected to send */
+    switch(data->set.httpreq) {
+    case HTTPREQ_POST:
+      if(data->state.infilesize != -1)
+        expectsend = data->state.infilesize;
+      break;
+    case HTTPREQ_PUT:
+      if(data->state.infilesize != -1)
+        expectsend = data->state.infilesize;
+      break;
+    case HTTPREQ_POST_FORM:
+    case HTTPREQ_POST_MIME:
+      expectsend = http->postsize;
+      break;
+    default:
+      break;
+    }
+  }
+
+  conn->bits.rewindaftersend = FALSE; /* default */
+
+  if((expectsend == -1) || (expectsend > bytessent)) {
+#if defined(USE_NTLM)
+    /* There is still data left to send */
+    if((data->state.authproxy.picked == CURLAUTH_NTLM) ||
+       (data->state.authhost.picked == CURLAUTH_NTLM) ||
+       (data->state.authproxy.picked == CURLAUTH_NTLM_WB) ||
+       (data->state.authhost.picked == CURLAUTH_NTLM_WB)) {
+      if(((expectsend - bytessent) < 2000) ||
+         (conn->http_ntlm_state != NTLMSTATE_NONE) ||
+         (conn->proxy_ntlm_state != NTLMSTATE_NONE)) {
+        /* The NTLM-negotiation has started *OR* there is just a little (<2K)
+           data left to send, keep on sending. */
+
+        /* rewind data when completely done sending! */
+        if(!conn->bits.authneg && (conn->writesockfd != CURL_SOCKET_BAD)) {
+          conn->bits.rewindaftersend = TRUE;
+          infof(data, "Rewind stream after send\n");
+        }
+
+        return CURLE_OK;
+      }
+
+      if(conn->bits.close)
+        /* this is already marked to get closed */
+        return CURLE_OK;
+
+      infof(data, "NTLM send, close instead of sending %"
+            CURL_FORMAT_CURL_OFF_T " bytes\n",
+            (curl_off_t)(expectsend - bytessent));
+    }
+#endif
+#if defined(USE_SPNEGO)
+    /* There is still data left to send */
+    if((data->state.authproxy.picked == CURLAUTH_NEGOTIATE) ||
+       (data->state.authhost.picked == CURLAUTH_NEGOTIATE)) {
+      if(((expectsend - bytessent) < 2000) ||
+         (conn->http_negotiate_state != GSS_AUTHNONE) ||
+         (conn->proxy_negotiate_state != GSS_AUTHNONE)) {
+        /* The NEGOTIATE-negotiation has started *OR*
+        there is just a little (<2K) data left to send, keep on sending. */
+
+        /* rewind data when completely done sending! */
+        if(!conn->bits.authneg && (conn->writesockfd != CURL_SOCKET_BAD)) {
+          conn->bits.rewindaftersend = TRUE;
+          infof(data, "Rewind stream after send\n");
+        }
+
+        return CURLE_OK;
+      }
+
+      if(conn->bits.close)
+        /* this is already marked to get closed */
+        return CURLE_OK;
+
+      infof(data, "NEGOTIATE send, close instead of sending %"
+        CURL_FORMAT_CURL_OFF_T " bytes\n",
+        (curl_off_t)(expectsend - bytessent));
+    }
+#endif
+
+    /* This is not NEGOTIATE/NTLM or many bytes left to send: close */
+    streamclose(conn, "Mid-auth HTTP and much data left to send");
+    data->req.size = 0; /* don't download any more than 0 bytes */
+
+    /* There still is data left to send, but this connection is marked for
+       closure so we can safely do the rewind right now */
+  }
+
+  if(bytessent)
+    /* we rewind now at once since if we already sent something */
+    return Curl_readrewind(conn);
+
+  return CURLE_OK;
+}
+
+/*
+ * Curl_http_auth_act() gets called when all HTTP headers have been received
+ * and it checks what authentication methods that are available and decides
+ * which one (if any) to use. It will set 'newurl' if an auth method was
+ * picked.
+ */
+
+CURLcode Curl_http_auth_act(struct connectdata *conn)
+{
+  struct Curl_easy *data = conn->data;
+  bool pickhost = FALSE;
+  bool pickproxy = FALSE;
+  CURLcode result = CURLE_OK;
+  unsigned long authmask = ~0ul;
+
+  if(!conn->oauth_bearer)
+    authmask &= (unsigned long)~CURLAUTH_BEARER;
+
+  if(100 <= data->req.httpcode && 199 >= data->req.httpcode)
+    /* this is a transient response code, ignore */
+    return CURLE_OK;
+
+  if(data->state.authproblem)
+    return data->set.http_fail_on_error?CURLE_HTTP_RETURNED_ERROR:CURLE_OK;
+
+  if((conn->bits.user_passwd || conn->oauth_bearer) &&
+     ((data->req.httpcode == 401) ||
+      (conn->bits.authneg && data->req.httpcode < 300))) {
+    pickhost = pickoneauth(&data->state.authhost, authmask);
+    if(!pickhost)
+      data->state.authproblem = TRUE;
+    if(data->state.authhost.picked == CURLAUTH_NTLM &&
+       conn->httpversion > 11) {
+      infof(data, "Forcing HTTP/1.1 for NTLM");
+      connclose(conn, "Force HTTP/1.1 connection");
+      conn->data->set.httpversion = CURL_HTTP_VERSION_1_1;
+    }
+  }
+  if(conn->bits.proxy_user_passwd &&
+     ((data->req.httpcode == 407) ||
+      (conn->bits.authneg && data->req.httpcode < 300))) {
+    pickproxy = pickoneauth(&data->state.authproxy,
+                            authmask & ~CURLAUTH_BEARER);
+    if(!pickproxy)
+      data->state.authproblem = TRUE;
+  }
+
+  if(pickhost || pickproxy) {
+    if((data->set.httpreq != HTTPREQ_GET) &&
+       (data->set.httpreq != HTTPREQ_HEAD) &&
+       !conn->bits.rewindaftersend) {
+      result = http_perhapsrewind(conn);
+      if(result)
+        return result;
+    }
+    /* In case this is GSS auth, the newurl field is already allocated so
+       we must make sure to free it before allocating a new one. As figured
+       out in bug #2284386 */
+    Curl_safefree(data->req.newurl);
+    data->req.newurl = strdup(data->change.url); /* clone URL */
+    if(!data->req.newurl)
+      return CURLE_OUT_OF_MEMORY;
+  }
+  else if((data->req.httpcode < 300) &&
+          (!data->state.authhost.done) &&
+          conn->bits.authneg) {
+    /* no (known) authentication available,
+       authentication is not "done" yet and
+       no authentication seems to be required and
+       we didn't try HEAD or GET */
+    if((data->set.httpreq != HTTPREQ_GET) &&
+       (data->set.httpreq != HTTPREQ_HEAD)) {
+      data->req.newurl = strdup(data->change.url); /* clone URL */
+      if(!data->req.newurl)
+        return CURLE_OUT_OF_MEMORY;
+      data->state.authhost.done = TRUE;
+    }
+  }
+  if(http_should_fail(conn)) {
+    failf(data, "The requested URL returned error: %d",
+          data->req.httpcode);
+    result = CURLE_HTTP_RETURNED_ERROR;
+  }
+
+  return result;
+}
+
+#ifndef CURL_DISABLE_HTTP_AUTH
+/*
+ * Output the correct authentication header depending on the auth type
+ * and whether or not it is to a proxy.
+ */
+static CURLcode
+output_auth_headers(struct connectdata *conn,
+                    struct auth *authstatus,
+                    const char *request,
+                    const char *path,
+                    bool proxy)
+{
+  const char *auth = NULL;
+  CURLcode result = CURLE_OK;
+#if !defined(CURL_DISABLE_VERBOSE_STRINGS) || defined(USE_SPNEGO)
+  struct Curl_easy *data = conn->data;
+#endif
+
+#ifdef CURL_DISABLE_CRYPTO_AUTH
+  (void)request;
+  (void)path;
+#endif
+
+#ifdef USE_SPNEGO
+  if(authstatus->picked == CURLAUTH_NEGOTIATE) {
+    auth = "Negotiate";
+    result = Curl_output_negotiate(conn, proxy);
+    if(result)
+      return result;
+  }
+  else
+#endif
+#ifdef USE_NTLM
+  if(authstatus->picked == CURLAUTH_NTLM) {
+    auth = "NTLM";
+    result = Curl_output_ntlm(conn, proxy);
+    if(result)
+      return result;
+  }
+  else
+#endif
+#if defined(USE_NTLM) && defined(NTLM_WB_ENABLED)
+  if(authstatus->picked == CURLAUTH_NTLM_WB) {
+    auth = "NTLM_WB";
+    result = Curl_output_ntlm_wb(conn, proxy);
+    if(result)
+      return result;
+  }
+  else
+#endif
+#ifndef CURL_DISABLE_CRYPTO_AUTH
+  if(authstatus->picked == CURLAUTH_DIGEST) {
+    auth = "Digest";
+    result = Curl_output_digest(conn,
+                                proxy,
+                                (const unsigned char *)request,
+                                (const unsigned char *)path);
+    if(result)
+      return result;
+  }
+  else
+#endif
+  if(authstatus->picked == CURLAUTH_BASIC) {
+    /* Basic */
+    if((proxy && conn->bits.proxy_user_passwd &&
+        !Curl_checkProxyheaders(conn, "Proxy-authorization")) ||
+       (!proxy && conn->bits.user_passwd &&
+        !Curl_checkheaders(conn, "Authorization"))) {
+      auth = "Basic";
+      result = http_output_basic(conn, proxy);
+      if(result)
+        return result;
+    }
+
+    /* NOTE: this function should set 'done' TRUE, as the other auth
+       functions work that way */
+    authstatus->done = TRUE;
+  }
+  if(authstatus->picked == CURLAUTH_BEARER) {
+    /* Bearer */
+    if((!proxy && conn->oauth_bearer &&
+        !Curl_checkheaders(conn, "Authorization:"))) {
+      auth = "Bearer";
+      result = http_output_bearer(conn);
+      if(result)
+        return result;
+    }
+
+    /* NOTE: this function should set 'done' TRUE, as the other auth
+       functions work that way */
+    authstatus->done = TRUE;
+  }
+
+  if(auth) {
+    infof(data, "%s auth using %s with user '%s'\n",
+          proxy ? "Proxy" : "Server", auth,
+          proxy ? (conn->http_proxy.user ? conn->http_proxy.user : "") :
+                  (conn->user ? conn->user : ""));
+    authstatus->multipass = (!authstatus->done) ? TRUE : FALSE;
+  }
+  else
+    authstatus->multipass = FALSE;
+
+  return CURLE_OK;
+}
+
+/**
+ * Curl_http_output_auth() setups the authentication headers for the
+ * host/proxy and the correct authentication
+ * method. conn->data->state.authdone is set to TRUE when authentication is
+ * done.
+ *
+ * @param conn all information about the current connection
+ * @param request pointer to the request keyword
+ * @param path pointer to the requested path; should include query part
+ * @param proxytunnel boolean if this is the request setting up a "proxy
+ * tunnel"
+ *
+ * @returns CURLcode
+ */
+CURLcode
+Curl_http_output_auth(struct connectdata *conn,
+                      const char *request,
+                      const char *path,
+                      bool proxytunnel) /* TRUE if this is the request setting
+                                           up the proxy tunnel */
+{
+  CURLcode result = CURLE_OK;
+  struct Curl_easy *data = conn->data;
+  struct auth *authhost;
+  struct auth *authproxy;
+
+  DEBUGASSERT(data);
+
+  authhost = &data->state.authhost;
+  authproxy = &data->state.authproxy;
+
+  if((conn->bits.httpproxy && conn->bits.proxy_user_passwd) ||
+     conn->bits.user_passwd || conn->oauth_bearer)
+    /* continue please */;
+  else {
+    authhost->done = TRUE;
+    authproxy->done = TRUE;
+    return CURLE_OK; /* no authentication with no user or password */
+  }
+
+  if(authhost->want && !authhost->picked)
+    /* The app has selected one or more methods, but none has been picked
+       so far by a server round-trip. Then we set the picked one to the
+       want one, and if this is one single bit it'll be used instantly. */
+    authhost->picked = authhost->want;
+
+  if(authproxy->want && !authproxy->picked)
+    /* The app has selected one or more methods, but none has been picked so
+       far by a proxy round-trip. Then we set the picked one to the want one,
+       and if this is one single bit it'll be used instantly. */
+    authproxy->picked = authproxy->want;
+
+#ifndef CURL_DISABLE_PROXY
+  /* Send proxy authentication header if needed */
+  if(conn->bits.httpproxy &&
+     (conn->bits.tunnel_proxy == (bit)proxytunnel)) {
+    result = output_auth_headers(conn, authproxy, request, path, TRUE);
+    if(result)
+      return result;
+  }
+  else
+#else
+  (void)proxytunnel;
+#endif /* CURL_DISABLE_PROXY */
+    /* we have no proxy so let's pretend we're done authenticating
+       with it */
+    authproxy->done = TRUE;
+
+  /* To prevent the user+password to get sent to other than the original
+     host due to a location-follow, we do some weirdo checks here */
+  if(!data->state.this_is_a_follow ||
+     conn->bits.netrc ||
+     !data->state.first_host ||
+     data->set.allow_auth_to_other_hosts ||
+     strcasecompare(data->state.first_host, conn->host.name)) {
+    result = output_auth_headers(conn, authhost, request, path, FALSE);
+  }
+  else
+    authhost->done = TRUE;
+
+  return result;
+}
+
+#else
+/* when disabled */
+CURLcode
+Curl_http_output_auth(struct connectdata *conn,
+                      const char *request,
+                      const char *path,
+                      bool proxytunnel)
+{
+  (void)conn;
+  (void)request;
+  (void)path;
+  (void)proxytunnel;
+  return CURLE_OK;
+}
+#endif
+
+/*
+ * Curl_http_input_auth() deals with Proxy-Authenticate: and WWW-Authenticate:
+ * headers. They are dealt with both in the transfer.c main loop and in the
+ * proxy CONNECT loop.
+ */
+
+CURLcode Curl_http_input_auth(struct connectdata *conn, bool proxy,
+                              const char *auth) /* the first non-space */
+{
+  /*
+   * This resource requires authentication
+   */
+  struct Curl_easy *data = conn->data;
+
+#ifdef USE_SPNEGO
+  curlnegotiate *negstate = proxy ? &conn->proxy_negotiate_state :
+                                    &conn->http_negotiate_state;
+#endif
+  unsigned long *availp;
+  struct auth *authp;
+
+  if(proxy) {
+    availp = &data->info.proxyauthavail;
+    authp = &data->state.authproxy;
+  }
+  else {
+    availp = &data->info.httpauthavail;
+    authp = &data->state.authhost;
+  }
+
+  /*
+   * Here we check if we want the specific single authentication (using ==) and
+   * if we do, we initiate usage of it.
+   *
+   * If the provided authentication is wanted as one out of several accepted
+   * types (using &), we OR this authentication type to the authavail
+   * variable.
+   *
+   * Note:
+   *
+   * ->picked is first set to the 'want' value (one or more bits) before the
+   * request is sent, and then it is again set _after_ all response 401/407
+   * headers have been received but then only to a single preferred method
+   * (bit).
+   */
+
+  while(*auth) {
+#ifdef USE_SPNEGO
+    if(checkprefix("Negotiate", auth)) {
+      if((authp->avail & CURLAUTH_NEGOTIATE) ||
+         Curl_auth_is_spnego_supported()) {
+        *availp |= CURLAUTH_NEGOTIATE;
+        authp->avail |= CURLAUTH_NEGOTIATE;
+
+        if(authp->picked == CURLAUTH_NEGOTIATE) {
+          CURLcode result = Curl_input_negotiate(conn, proxy, auth);
+          if(!result) {
+            DEBUGASSERT(!data->req.newurl);
+            data->req.newurl = strdup(data->change.url);
+            if(!data->req.newurl)
+              return CURLE_OUT_OF_MEMORY;
+            data->state.authproblem = FALSE;
+            /* we received a GSS auth token and we dealt with it fine */
+            *negstate = GSS_AUTHRECV;
+          }
+          else
+            data->state.authproblem = TRUE;
+        }
+      }
+    }
+    else
+#endif
+#ifdef USE_NTLM
+      /* NTLM support requires the SSL crypto libs */
+      if(checkprefix("NTLM", auth)) {
+        if((authp->avail & CURLAUTH_NTLM) ||
+           (authp->avail & CURLAUTH_NTLM_WB) ||
+           Curl_auth_is_ntlm_supported()) {
+          *availp |= CURLAUTH_NTLM;
+          authp->avail |= CURLAUTH_NTLM;
+
+          if(authp->picked == CURLAUTH_NTLM ||
+             authp->picked == CURLAUTH_NTLM_WB) {
+            /* NTLM authentication is picked and activated */
+            CURLcode result = Curl_input_ntlm(conn, proxy, auth);
+            if(!result) {
+              data->state.authproblem = FALSE;
+#ifdef NTLM_WB_ENABLED
+              if(authp->picked == CURLAUTH_NTLM_WB) {
+                *availp &= ~CURLAUTH_NTLM;
+                authp->avail &= ~CURLAUTH_NTLM;
+                *availp |= CURLAUTH_NTLM_WB;
+                authp->avail |= CURLAUTH_NTLM_WB;
+
+                result = Curl_input_ntlm_wb(conn, proxy, auth);
+                if(result) {
+                  infof(data, "Authentication problem. Ignoring this.\n");
+                  data->state.authproblem = TRUE;
+                }
+              }
+#endif
+            }
+            else {
+              infof(data, "Authentication problem. Ignoring this.\n");
+              data->state.authproblem = TRUE;
+            }
+          }
+        }
+      }
+      else
+#endif
+#ifndef CURL_DISABLE_CRYPTO_AUTH
+        if(checkprefix("Digest", auth)) {
+          if((authp->avail & CURLAUTH_DIGEST) != 0)
+            infof(data, "Ignoring duplicate digest auth header.\n");
+          else if(Curl_auth_is_digest_supported()) {
+            CURLcode result;
+
+            *availp |= CURLAUTH_DIGEST;
+            authp->avail |= CURLAUTH_DIGEST;
+
+            /* We call this function on input Digest headers even if Digest
+             * authentication isn't activated yet, as we need to store the
+             * incoming data from this header in case we are going to use
+             * Digest */
+            result = Curl_input_digest(conn, proxy, auth);
+            if(result) {
+              infof(data, "Authentication problem. Ignoring this.\n");
+              data->state.authproblem = TRUE;
+            }
+          }
+        }
+        else
+#endif
+          if(checkprefix("Basic", auth)) {
+            *availp |= CURLAUTH_BASIC;
+            authp->avail |= CURLAUTH_BASIC;
+            if(authp->picked == CURLAUTH_BASIC) {
+              /* We asked for Basic authentication but got a 40X back
+                 anyway, which basically means our name+password isn't
+                 valid. */
+              authp->avail = CURLAUTH_NONE;
+              infof(data, "Authentication problem. Ignoring this.\n");
+              data->state.authproblem = TRUE;
+            }
+          }
+          else
+            if(checkprefix("Bearer", auth)) {
+              *availp |= CURLAUTH_BEARER;
+              authp->avail |= CURLAUTH_BEARER;
+              if(authp->picked == CURLAUTH_BEARER) {
+                /* We asked for Bearer authentication but got a 40X back
+                  anyway, which basically means our token isn't valid. */
+                authp->avail = CURLAUTH_NONE;
+                infof(data, "Authentication problem. Ignoring this.\n");
+                data->state.authproblem = TRUE;
+              }
+            }
+
+    /* there may be multiple methods on one line, so keep reading */
+    while(*auth && *auth != ',') /* read up to the next comma */
+      auth++;
+    if(*auth == ',') /* if we're on a comma, skip it */
+      auth++;
+    while(*auth && ISSPACE(*auth))
+      auth++;
+  }
+
+  return CURLE_OK;
+}
+
+/**
+ * http_should_fail() determines whether an HTTP response has gotten us
+ * into an error state or not.
+ *
+ * @param conn all information about the current connection
+ *
+ * @retval 0 communications should continue
+ *
+ * @retval 1 communications should not continue
+ */
+static int http_should_fail(struct connectdata *conn)
+{
+  struct Curl_easy *data;
+  int httpcode;
+
+  DEBUGASSERT(conn);
+  data = conn->data;
+  DEBUGASSERT(data);
+
+  httpcode = data->req.httpcode;
+
+  /*
+  ** If we haven't been asked to fail on error,
+  ** don't fail.
+  */
+  if(!data->set.http_fail_on_error)
+    return 0;
+
+  /*
+  ** Any code < 400 is never terminal.
+  */
+  if(httpcode < 400)
+    return 0;
+
+  /*
+  ** Any code >= 400 that's not 401 or 407 is always
+  ** a terminal error
+  */
+  if((httpcode != 401) && (httpcode != 407))
+    return 1;
+
+  /*
+  ** All we have left to deal with is 401 and 407
+  */
+  DEBUGASSERT((httpcode == 401) || (httpcode == 407));
+
+  /*
+  ** Examine the current authentication state to see if this
+  ** is an error.  The idea is for this function to get
+  ** called after processing all the headers in a response
+  ** message.  So, if we've been to asked to authenticate a
+  ** particular stage, and we've done it, we're OK.  But, if
+  ** we're already completely authenticated, it's not OK to
+  ** get another 401 or 407.
+  **
+  ** It is possible for authentication to go stale such that
+  ** the client needs to reauthenticate.  Once that info is
+  ** available, use it here.
+  */
+
+  /*
+  ** Either we're not authenticating, or we're supposed to
+  ** be authenticating something else.  This is an error.
+  */
+  if((httpcode == 401) && !conn->bits.user_passwd)
+    return TRUE;
+  if((httpcode == 407) && !conn->bits.proxy_user_passwd)
+    return TRUE;
+
+  return data->state.authproblem;
+}
+
+/*
+ * readmoredata() is a "fread() emulation" to provide POST and/or request
+ * data. It is used when a huge POST is to be made and the entire chunk wasn't
+ * sent in the first send(). This function will then be called from the
+ * transfer.c loop when more data is to be sent to the peer.
+ *
+ * Returns the amount of bytes it filled the buffer with.
+ */
+static size_t readmoredata(char *buffer,
+                           size_t size,
+                           size_t nitems,
+                           void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct HTTP *http = conn->data->req.protop;
+  size_t fullsize = size * nitems;
+
+  if(!http->postsize)
+    /* nothing to return */
+    return 0;
+
+  /* make sure that a HTTP request is never sent away chunked! */
+  conn->data->req.forbidchunk = (http->sending == HTTPSEND_REQUEST)?TRUE:FALSE;
+
+  if(http->postsize <= (curl_off_t)fullsize) {
+    memcpy(buffer, http->postdata, (size_t)http->postsize);
+    fullsize = (size_t)http->postsize;
+
+    if(http->backup.postsize) {
+      /* move backup data into focus and continue on that */
+      http->postdata = http->backup.postdata;
+      http->postsize = http->backup.postsize;
+      conn->data->state.fread_func = http->backup.fread_func;
+      conn->data->state.in = http->backup.fread_in;
+
+      http->sending++; /* move one step up */
+
+      http->backup.postsize = 0;
+    }
+    else
+      http->postsize = 0;
+
+    return fullsize;
+  }
+
+  memcpy(buffer, http->postdata, fullsize);
+  http->postdata += fullsize;
+  http->postsize -= fullsize;
+
+  return fullsize;
+}
+
+/* ------------------------------------------------------------------------- */
+/* add_buffer functions */
+
+/*
+ * Curl_add_buffer_init() sets up and returns a fine buffer struct
+ */
+Curl_send_buffer *Curl_add_buffer_init(void)
+{
+  return calloc(1, sizeof(Curl_send_buffer));
+}
+
+/*
+ * Curl_add_buffer_free() frees all associated resources.
+ */
+void Curl_add_buffer_free(Curl_send_buffer **inp)
+{
+  Curl_send_buffer *in;
+  if(!inp)
+    return;
+  in = *inp;
+  if(in) { /* deal with NULL input */
+    free(in->buffer);
+    free(in);
+  }
+  *inp = NULL;
+}
+
+/*
+ * Curl_add_buffer_send() sends a header buffer and frees all associated
+ * memory.  Body data may be appended to the header data if desired.
+ *
+ * Returns CURLcode
+ */
+CURLcode Curl_add_buffer_send(Curl_send_buffer **inp,
+                              struct connectdata *conn,
+
+                              /* add the number of sent bytes to this
+                                 counter */
+                              curl_off_t *bytes_written,
+
+                              /* how much of the buffer contains body data */
+                              size_t included_body_bytes,
+                              int socketindex)
+{
+  ssize_t amount;
+  CURLcode result;
+  char *ptr;
+  size_t size;
+  struct Curl_easy *data = conn->data;
+  struct HTTP *http = data->req.protop;
+  size_t sendsize;
+  curl_socket_t sockfd;
+  size_t headersize;
+  Curl_send_buffer *in = *inp;
+
+  DEBUGASSERT(socketindex <= SECONDARYSOCKET);
+
+  sockfd = conn->sock[socketindex];
+
+  /* The looping below is required since we use non-blocking sockets, but due
+     to the circumstances we will just loop and try again and again etc */
+
+  ptr = in->buffer;
+  size = in->size_used;
+
+  headersize = size - included_body_bytes; /* the initial part that isn't body
+                                              is header */
+
+  DEBUGASSERT(size > included_body_bytes);
+
+  result = Curl_convert_to_network(data, ptr, headersize);
+  /* Curl_convert_to_network calls failf if unsuccessful */
+  if(result) {
+    /* conversion failed, free memory and return to the caller */
+    Curl_add_buffer_free(inp);
+    return result;
+  }
+
+  if((conn->handler->flags & PROTOPT_SSL ||
+     conn->http_proxy.proxytype == CURLPROXY_HTTPS)
+     && conn->httpversion != 20) {
+    /* We never send more than CURL_MAX_WRITE_SIZE bytes in one single chunk
+       when we speak HTTPS, as if only a fraction of it is sent now, this data
+       needs to fit into the normal read-callback buffer later on and that
+       buffer is using this size.
+    */
+
+    sendsize = CURLMIN(size, CURL_MAX_WRITE_SIZE);
+
+    /* OpenSSL is very picky and we must send the SAME buffer pointer to the
+       library when we attempt to re-send this buffer. Sending the same data
+       is not enough, we must use the exact same address. For this reason, we
+       must copy the data to the uploadbuffer first, since that is the buffer
+       we will be using if this send is retried later.
+    */
+    result = Curl_get_upload_buffer(data);
+    if(result) {
+      /* malloc failed, free memory and return to the caller */
+      Curl_add_buffer_free(&in);
+      return result;
+    }
+    memcpy(data->state.ulbuf, ptr, sendsize);
+    ptr = data->state.ulbuf;
+  }
+  else
+    sendsize = size;
+
+  result = Curl_write(conn, sockfd, ptr, sendsize, &amount);
+
+  if(!result) {
+    /*
+     * Note that we may not send the entire chunk at once, and we have a set
+     * number of data bytes at the end of the big buffer (out of which we may
+     * only send away a part).
+     */
+    /* how much of the header that was sent */
+    size_t headlen = (size_t)amount>headersize ? headersize : (size_t)amount;
+    size_t bodylen = amount - headlen;
+
+    if(data->set.verbose) {
+      /* this data _may_ contain binary stuff */
+      Curl_debug(data, CURLINFO_HEADER_OUT, ptr, headlen);
+      if(bodylen) {
+        /* there was body data sent beyond the initial header part, pass that
+           on to the debug callback too */
+        Curl_debug(data, CURLINFO_DATA_OUT,
+                   ptr + headlen, bodylen);
+      }
+    }
+
+    /* 'amount' can never be a very large value here so typecasting it so a
+       signed 31 bit value should not cause problems even if ssize_t is
+       64bit */
+    *bytes_written += (long)amount;
+
+    if(http) {
+      /* if we sent a piece of the body here, up the byte counter for it
+         accordingly */
+      data->req.writebytecount += bodylen;
+      Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
+
+      if((size_t)amount != size) {
+        /* The whole request could not be sent in one system call. We must
+           queue it up and send it later when we get the chance. We must not
+           loop here and wait until it might work again. */
+
+        size -= amount;
+
+        ptr = in->buffer + amount;
+
+        /* backup the currently set pointers */
+        http->backup.fread_func = data->state.fread_func;
+        http->backup.fread_in = data->state.in;
+        http->backup.postdata = http->postdata;
+        http->backup.postsize = http->postsize;
+
+        /* set the new pointers for the request-sending */
+        data->state.fread_func = (curl_read_callback)readmoredata;
+        data->state.in = (void *)conn;
+        http->postdata = ptr;
+        http->postsize = (curl_off_t)size;
+
+        http->send_buffer = in;
+        http->sending = HTTPSEND_REQUEST;
+
+        return CURLE_OK;
+      }
+      http->sending = HTTPSEND_BODY;
+      /* the full buffer was sent, clean up and return */
+    }
+    else {
+      if((size_t)amount != size)
+        /* We have no continue-send mechanism now, fail. This can only happen
+           when this function is used from the CONNECT sending function. We
+           currently (stupidly) assume that the whole request is always sent
+           away in the first single chunk.
+
+           This needs FIXing.
+        */
+        return CURLE_SEND_ERROR;
+    }
+  }
+  Curl_add_buffer_free(&in);
+
+  return result;
+}
+
+
+/*
+ * add_bufferf() add the formatted input to the buffer.
+ */
+CURLcode Curl_add_bufferf(Curl_send_buffer **inp, const char *fmt, ...)
+{
+  char *s;
+  va_list ap;
+  Curl_send_buffer *in = *inp;
+  va_start(ap, fmt);
+  s = vaprintf(fmt, ap); /* this allocs a new string to append */
+  va_end(ap);
+
+  if(s) {
+    CURLcode result = Curl_add_buffer(inp, s, strlen(s));
+    free(s);
+    return result;
+  }
+  /* If we failed, we cleanup the whole buffer and return error */
+  free(in->buffer);
+  free(in);
+  *inp = NULL;
+  return CURLE_OUT_OF_MEMORY;
+}
+
+/*
+ * Curl_add_buffer() appends a memory chunk to the existing buffer
+ */
+CURLcode Curl_add_buffer(Curl_send_buffer **inp, const void *inptr,
+                         size_t size)
+{
+  char *new_rb;
+  Curl_send_buffer *in = *inp;
+
+  if(~size < in->size_used) {
+    /* If resulting used size of send buffer would wrap size_t, cleanup
+       the whole buffer and return error. Otherwise the required buffer
+       size will fit into a single allocatable memory chunk */
+    Curl_safefree(in->buffer);
+    free(in);
+    *inp = NULL;
+    return CURLE_OUT_OF_MEMORY;
+  }
+
+  if(!in->buffer ||
+     ((in->size_used + size) > (in->size_max - 1))) {
+    /* If current buffer size isn't enough to hold the result, use a
+       buffer size that doubles the required size. If this new size
+       would wrap size_t, then just use the largest possible one */
+    size_t new_size;
+
+    if((size > (size_t)-1 / 2) || (in->size_used > (size_t)-1 / 2) ||
+       (~(size * 2) < (in->size_used * 2)))
+      new_size = (size_t)-1;
+    else
+      new_size = (in->size_used + size) * 2;
+
+    if(in->buffer)
+      /* we have a buffer, enlarge the existing one */
+      new_rb = Curl_saferealloc(in->buffer, new_size);
+    else
+      /* create a new buffer */
+      new_rb = malloc(new_size);
+
+    if(!new_rb) {
+      /* If we failed, we cleanup the whole buffer and return error */
+      free(in);
+      *inp = NULL;
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    in->buffer = new_rb;
+    in->size_max = new_size;
+  }
+  memcpy(&in->buffer[in->size_used], inptr, size);
+
+  in->size_used += size;
+
+  return CURLE_OK;
+}
+
+/* end of the add_buffer functions */
+/* ------------------------------------------------------------------------- */
+
+
+
+/*
+ * Curl_compareheader()
+ *
+ * Returns TRUE if 'headerline' contains the 'header' with given 'content'.
+ * Pass headers WITH the colon.
+ */
+bool
+Curl_compareheader(const char *headerline, /* line to check */
+                   const char *header,  /* header keyword _with_ colon */
+                   const char *content) /* content string to find */
+{
+  /* RFC2616, section 4.2 says: "Each header field consists of a name followed
+   * by a colon (":") and the field value. Field names are case-insensitive.
+   * The field value MAY be preceded by any amount of LWS, though a single SP
+   * is preferred." */
+
+  size_t hlen = strlen(header);
+  size_t clen;
+  size_t len;
+  const char *start;
+  const char *end;
+
+  if(!strncasecompare(headerline, header, hlen))
+    return FALSE; /* doesn't start with header */
+
+  /* pass the header */
+  start = &headerline[hlen];
+
+  /* pass all white spaces */
+  while(*start && ISSPACE(*start))
+    start++;
+
+  /* find the end of the header line */
+  end = strchr(start, '\r'); /* lines end with CRLF */
+  if(!end) {
+    /* in case there's a non-standard compliant line here */
+    end = strchr(start, '\n');
+
+    if(!end)
+      /* hm, there's no line ending here, use the zero byte! */
+      end = strchr(start, '\0');
+  }
+
+  len = end-start; /* length of the content part of the input line */
+  clen = strlen(content); /* length of the word to find */
+
+  /* find the content string in the rest of the line */
+  for(; len >= clen; len--, start++) {
+    if(strncasecompare(start, content, clen))
+      return TRUE; /* match! */
+  }
+
+  return FALSE; /* no match */
+}
+
+/*
+ * Curl_http_connect() performs HTTP stuff to do at connect-time, called from
+ * the generic Curl_connect().
+ */
+CURLcode Curl_http_connect(struct connectdata *conn, bool *done)
+{
+  CURLcode result;
+
+  /* We default to persistent connections. We set this already in this connect
+     function to make the re-use checks properly be able to check this bit. */
+  connkeep(conn, "HTTP default");
+
+  /* the CONNECT procedure might not have been completed */
+  result = Curl_proxy_connect(conn, FIRSTSOCKET);
+  if(result)
+    return result;
+
+  if(conn->bits.proxy_connect_closed)
+    /* this is not an error, just part of the connection negotiation */
+    return CURLE_OK;
+
+  if(CONNECT_FIRSTSOCKET_PROXY_SSL())
+    return CURLE_OK; /* wait for HTTPS proxy SSL initialization to complete */
+
+  if(Curl_connect_ongoing(conn))
+    /* nothing else to do except wait right now - we're not done here. */
+    return CURLE_OK;
+
+#ifndef CURL_DISABLE_PROXY
+  if(conn->data->set.haproxyprotocol) {
+    /* add HAProxy PROXY protocol header */
+    result = add_haproxy_protocol_header(conn);
+    if(result)
+      return result;
+  }
+#endif
+
+  if(conn->given->protocol & CURLPROTO_HTTPS) {
+    /* perform SSL initialization */
+    result = https_connecting(conn, done);
+    if(result)
+      return result;
+  }
+  else
+    *done = TRUE;
+
+  return CURLE_OK;
+}
+
+/* this returns the socket to wait for in the DO and DOING state for the multi
+   interface and then we're always _sending_ a request and thus we wait for
+   the single socket to become writable only */
+static int http_getsock_do(struct connectdata *conn,
+                           curl_socket_t *socks)
+{
+  /* write mode */
+  socks[0] = conn->sock[FIRSTSOCKET];
+  return GETSOCK_WRITESOCK(0);
+}
+
+#ifndef CURL_DISABLE_PROXY
+static CURLcode add_haproxy_protocol_header(struct connectdata *conn)
+{
+  char proxy_header[128];
+  Curl_send_buffer *req_buffer;
+  CURLcode result;
+  char tcp_version[5];
+
+  /* Emit the correct prefix for IPv6 */
+  if(conn->bits.ipv6) {
+    strcpy(tcp_version, "TCP6");
+  }
+  else {
+    strcpy(tcp_version, "TCP4");
+  }
+
+  msnprintf(proxy_header,
+            sizeof(proxy_header),
+            "PROXY %s %s %s %li %li\r\n",
+            tcp_version,
+            conn->data->info.conn_local_ip,
+            conn->data->info.conn_primary_ip,
+            conn->data->info.conn_local_port,
+            conn->data->info.conn_primary_port);
+
+  req_buffer = Curl_add_buffer_init();
+  if(!req_buffer)
+    return CURLE_OUT_OF_MEMORY;
+
+  result = Curl_add_bufferf(&req_buffer, proxy_header);
+  if(result)
+    return result;
+
+  result = Curl_add_buffer_send(&req_buffer,
+                                conn,
+                                &conn->data->info.request_size,
+                                0,
+                                FIRSTSOCKET);
+
+  return result;
+}
+#endif
+
+#ifdef USE_SSL
+static CURLcode https_connecting(struct connectdata *conn, bool *done)
+{
+  CURLcode result;
+  DEBUGASSERT((conn) && (conn->handler->flags & PROTOPT_SSL));
+
+#ifdef ENABLE_QUIC
+  if(conn->transport == TRNSPRT_QUIC) {
+    *done = TRUE;
+    return CURLE_OK;
+  }
+#endif
+
+  /* perform SSL initialization for this socket */
+  result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, done);
+  if(result)
+    connclose(conn, "Failed HTTPS connection");
+
+  return result;
+}
+
+static int https_getsock(struct connectdata *conn,
+                         curl_socket_t *socks)
+{
+  if(conn->handler->flags & PROTOPT_SSL)
+    return Curl_ssl_getsock(conn, socks);
+  return GETSOCK_BLANK;
+}
+#endif /* USE_SSL */
+
+/*
+ * Curl_http_done() gets called after a single HTTP request has been
+ * performed.
+ */
+
+CURLcode Curl_http_done(struct connectdata *conn,
+                        CURLcode status, bool premature)
+{
+  struct Curl_easy *data = conn->data;
+  struct HTTP *http = data->req.protop;
+
+  /* Clear multipass flag. If authentication isn't done yet, then it will get
+   * a chance to be set back to true when we output the next auth header */
+  data->state.authhost.multipass = FALSE;
+  data->state.authproxy.multipass = FALSE;
+
+  Curl_unencode_cleanup(conn);
+
+  /* set the proper values (possibly modified on POST) */
+  conn->seek_func = data->set.seek_func; /* restore */
+  conn->seek_client = data->set.seek_client; /* restore */
+
+  if(!http)
+    return CURLE_OK;
+
+  if(http->send_buffer) {
+    Curl_add_buffer_free(&http->send_buffer);
+  }
+
+  Curl_http2_done(conn, premature);
+
+  Curl_mime_cleanpart(&http->form);
+
+  if(status)
+    return status;
+
+  if(!premature && /* this check is pointless when DONE is called before the
+                      entire operation is complete */
+     !conn->bits.retry &&
+     !data->set.connect_only &&
+     (data->req.bytecount +
+      data->req.headerbytecount -
+      data->req.deductheadercount) <= 0) {
+    /* If this connection isn't simply closed to be retried, AND nothing was
+       read from the HTTP server (that counts), this can't be right so we
+       return an error here */
+    failf(data, "Empty reply from server");
+    return CURLE_GOT_NOTHING;
+  }
+
+  return CURLE_OK;
+}
+
+/*
+ * Determine if we should use HTTP 1.1 (OR BETTER) for this request. Reasons
+ * to avoid it include:
+ *
+ * - if the user specifically requested HTTP 1.0
+ * - if the server we are connected to only supports 1.0
+ * - if any server previously contacted to handle this request only supports
+ * 1.0.
+ */
+static bool use_http_1_1plus(const struct Curl_easy *data,
+                             const struct connectdata *conn)
+{
+  if((data->state.httpversion == 10) || (conn->httpversion == 10))
+    return FALSE;
+  if((data->set.httpversion == CURL_HTTP_VERSION_1_0) &&
+     (conn->httpversion <= 10))
+    return FALSE;
+  return ((data->set.httpversion == CURL_HTTP_VERSION_NONE) ||
+          (data->set.httpversion >= CURL_HTTP_VERSION_1_1));
+}
+
+static const char *get_http_string(const struct Curl_easy *data,
+                                   const struct connectdata *conn)
+{
+#ifdef ENABLE_QUIC
+  if((data->set.httpversion == CURL_HTTP_VERSION_3) ||
+     (conn->httpversion == 30))
+    return "3";
+#endif
+
+#ifdef USE_NGHTTP2
+  if(conn->proto.httpc.h2)
+    return "2";
+#endif
+
+  if(use_http_1_1plus(data, conn))
+    return "1.1";
+
+  return "1.0";
+}
+
+/* check and possibly add an Expect: header */
+static CURLcode expect100(struct Curl_easy *data,
+                          struct connectdata *conn,
+                          Curl_send_buffer *req_buffer)
+{
+  CURLcode result = CURLE_OK;
+  data->state.expect100header = FALSE; /* default to false unless it is set
+                                          to TRUE below */
+  if(use_http_1_1plus(data, conn) &&
+     (conn->httpversion < 20)) {
+    /* if not doing HTTP 1.0 or version 2, or disabled explicitly, we add an
+       Expect: 100-continue to the headers which actually speeds up post
+       operations (as there is one packet coming back from the web server) */
+    const char *ptr = Curl_checkheaders(conn, "Expect");
+    if(ptr) {
+      data->state.expect100header =
+        Curl_compareheader(ptr, "Expect:", "100-continue");
+    }
+    else {
+      result = Curl_add_bufferf(&req_buffer,
+                                "Expect: 100-continue\r\n");
+      if(!result)
+        data->state.expect100header = TRUE;
+    }
+  }
+
+  return result;
+}
+
+enum proxy_use {
+  HEADER_SERVER,  /* direct to server */
+  HEADER_PROXY,   /* regular request to proxy */
+  HEADER_CONNECT  /* sending CONNECT to a proxy */
+};
+
+/* used to compile the provided trailers into one buffer
+   will return an error code if one of the headers is
+   not formatted correctly */
+CURLcode Curl_http_compile_trailers(struct curl_slist *trailers,
+                                    Curl_send_buffer **buffer,
+                                    struct Curl_easy *handle)
+{
+  char *ptr = NULL;
+  CURLcode result = CURLE_OK;
+  const char *endofline_native = NULL;
+  const char *endofline_network = NULL;
+
+  if(
+#ifdef CURL_DO_LINEEND_CONV
+     (handle->set.prefer_ascii) ||
+#endif
+     (handle->set.crlf)) {
+    /* \n will become \r\n later on */
+    endofline_native  = "\n";
+    endofline_network = "\x0a";
+  }
+  else {
+    endofline_native  = "\r\n";
+    endofline_network = "\x0d\x0a";
+  }
+
+  while(trailers) {
+    /* only add correctly formatted trailers */
+    ptr = strchr(trailers->data, ':');
+    if(ptr && *(ptr + 1) == ' ') {
+      result = Curl_add_bufferf(buffer, "%s%s", trailers->data,
+                                endofline_native);
+      if(result)
+        return result;
+    }
+    else
+      infof(handle, "Malformatted trailing header ! Skipping trailer.");
+    trailers = trailers->next;
+  }
+  result = Curl_add_buffer(buffer, endofline_network,
+                           strlen(endofline_network));
+  return result;
+}
+
+CURLcode Curl_add_custom_headers(struct connectdata *conn,
+                                 bool is_connect,
+                                 Curl_send_buffer *req_buffer)
+{
+  char *ptr;
+  struct curl_slist *h[2];
+  struct curl_slist *headers;
+  int numlists = 1; /* by default */
+  struct Curl_easy *data = conn->data;
+  int i;
+
+  enum proxy_use proxy;
+
+  if(is_connect)
+    proxy = HEADER_CONNECT;
+  else
+    proxy = conn->bits.httpproxy && !conn->bits.tunnel_proxy?
+      HEADER_PROXY:HEADER_SERVER;
+
+  switch(proxy) {
+  case HEADER_SERVER:
+    h[0] = data->set.headers;
+    break;
+  case HEADER_PROXY:
+    h[0] = data->set.headers;
+    if(data->set.sep_headers) {
+      h[1] = data->set.proxyheaders;
+      numlists++;
+    }
+    break;
+  case HEADER_CONNECT:
+    if(data->set.sep_headers)
+      h[0] = data->set.proxyheaders;
+    else
+      h[0] = data->set.headers;
+    break;
+  }
+
+  /* loop through one or two lists */
+  for(i = 0; i < numlists; i++) {
+    headers = h[i];
+
+    while(headers) {
+      char *semicolonp = NULL;
+      ptr = strchr(headers->data, ':');
+      if(!ptr) {
+        char *optr;
+        /* no colon, semicolon? */
+        ptr = strchr(headers->data, ';');
+        if(ptr) {
+          optr = ptr;
+          ptr++; /* pass the semicolon */
+          while(*ptr && ISSPACE(*ptr))
+            ptr++;
+
+          if(*ptr) {
+            /* this may be used for something else in the future */
+            optr = NULL;
+          }
+          else {
+            if(*(--ptr) == ';') {
+              /* copy the source */
+              semicolonp = strdup(headers->data);
+              if(!semicolonp) {
+                Curl_add_buffer_free(&req_buffer);
+                return CURLE_OUT_OF_MEMORY;
+              }
+              /* put a colon where the semicolon is */
+              semicolonp[ptr - headers->data] = ':';
+              /* point at the colon */
+              optr = &semicolonp [ptr - headers->data];
+            }
+          }
+          ptr = optr;
+        }
+      }
+      if(ptr) {
+        /* we require a colon for this to be a true header */
+
+        ptr++; /* pass the colon */
+        while(*ptr && ISSPACE(*ptr))
+          ptr++;
+
+        if(*ptr || semicolonp) {
+          /* only send this if the contents was non-blank or done special */
+          CURLcode result = CURLE_OK;
+          char *compare = semicolonp ? semicolonp : headers->data;
+
+          if(conn->allocptr.host &&
+             /* a Host: header was sent already, don't pass on any custom Host:
+                header as that will produce *two* in the same request! */
+             checkprefix("Host:", compare))
+            ;
+          else if(data->set.httpreq == HTTPREQ_POST_FORM &&
+                  /* this header (extended by formdata.c) is sent later */
+                  checkprefix("Content-Type:", compare))
+            ;
+          else if(data->set.httpreq == HTTPREQ_POST_MIME &&
+                  /* this header is sent later */
+                  checkprefix("Content-Type:", compare))
+            ;
+          else if(conn->bits.authneg &&
+                  /* while doing auth neg, don't allow the custom length since
+                     we will force length zero then */
+                  checkprefix("Content-Length:", compare))
+            ;
+          else if(conn->allocptr.te &&
+                  /* when asking for Transfer-Encoding, don't pass on a custom
+                     Connection: */
+                  checkprefix("Connection:", compare))
+            ;
+          else if((conn->httpversion >= 20) &&
+                  checkprefix("Transfer-Encoding:", compare))
+            /* HTTP/2 doesn't support chunked requests */
+            ;
+          else if((checkprefix("Authorization:", compare) ||
+                   checkprefix("Cookie:", compare)) &&
+                  /* be careful of sending this potentially sensitive header to
+                     other hosts */
+                  (data->state.this_is_a_follow &&
+                   data->state.first_host &&
+                   !data->set.allow_auth_to_other_hosts &&
+                   !strcasecompare(data->state.first_host, conn->host.name)))
+            ;
+          else {
+            result = Curl_add_bufferf(&req_buffer, "%s\r\n", compare);
+          }
+          if(semicolonp)
+            free(semicolonp);
+          if(result)
+            return result;
+        }
+      }
+      headers = headers->next;
+    }
+  }
+
+  return CURLE_OK;
+}
+
+#ifndef CURL_DISABLE_PARSEDATE
+CURLcode Curl_add_timecondition(const struct connectdata *conn,
+                                Curl_send_buffer *req_buffer)
+{
+  struct Curl_easy *data = conn->data;
+  const struct tm *tm;
+  struct tm keeptime;
+  CURLcode result;
+  char datestr[80];
+  const char *condp;
+
+  if(data->set.timecondition == CURL_TIMECOND_NONE)
+    /* no condition was asked for */
+    return CURLE_OK;
+
+  result = Curl_gmtime(data->set.timevalue, &keeptime);
+  if(result) {
+    failf(data, "Invalid TIMEVALUE");
+    return result;
+  }
+  tm = &keeptime;
+
+  switch(data->set.timecondition) {
+  default:
+    return CURLE_BAD_FUNCTION_ARGUMENT;
+
+  case CURL_TIMECOND_IFMODSINCE:
+    condp = "If-Modified-Since";
+    break;
+  case CURL_TIMECOND_IFUNMODSINCE:
+    condp = "If-Unmodified-Since";
+    break;
+  case CURL_TIMECOND_LASTMOD:
+    condp = "Last-Modified";
+    break;
+  }
+
+  if(Curl_checkheaders(conn, condp)) {
+    /* A custom header was specified; it will be sent instead. */
+    return CURLE_OK;
+  }
+
+  /* The If-Modified-Since header family should have their times set in
+   * GMT as RFC2616 defines: "All HTTP date/time stamps MUST be
+   * represented in Greenwich Mean Time (GMT), without exception. For the
+   * purposes of HTTP, GMT is exactly equal to UTC (Coordinated Universal
+   * Time)." (see page 20 of RFC2616).
+   */
+
+  /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */
+  msnprintf(datestr, sizeof(datestr),
+            "%s: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
+            condp,
+            Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
+            tm->tm_mday,
+            Curl_month[tm->tm_mon],
+            tm->tm_year + 1900,
+            tm->tm_hour,
+            tm->tm_min,
+            tm->tm_sec);
+
+  result = Curl_add_buffer(&req_buffer, datestr, strlen(datestr));
+
+  return result;
+}
+#else
+/* disabled */
+CURLcode Curl_add_timecondition(const struct connectdata *conn,
+                                Curl_send_buffer *req_buffer)
+{
+  (void)conn;
+  (void)req_buffer;
+  return CURLE_OK;
+}
+#endif
+
+/*
+ * Curl_http() gets called from the generic multi_do() function when a HTTP
+ * request is to be performed. This creates and sends a properly constructed
+ * HTTP request.
+ */
+CURLcode Curl_http(struct connectdata *conn, bool *done)
+{
+  struct Curl_easy *data = conn->data;
+  CURLcode result = CURLE_OK;
+  struct HTTP *http;
+  const char *path = data->state.up.path;
+  const char *query = data->state.up.query;
+  bool paste_ftp_userpwd = FALSE;
+  char ftp_typecode[sizeof("/;type=?")] = "";
+  const char *host = conn->host.name;
+  const char *te = ""; /* transfer-encoding */
+  const char *ptr;
+  const char *request;
+  Curl_HttpReq httpreq = data->set.httpreq;
+#if !defined(CURL_DISABLE_COOKIES)
+  char *addcookies = NULL;
+#endif
+  curl_off_t included_body = 0;
+  const char *httpstring;
+  Curl_send_buffer *req_buffer;
+  curl_off_t postsize = 0; /* curl_off_t to handle large file sizes */
+  char *altused = NULL;
+
+  /* Always consider the DO phase done after this function call, even if there
+     may be parts of the request that is not yet sent, since we can deal with
+     the rest of the request in the PERFORM phase. */
+  *done = TRUE;
+
+  if(conn->transport != TRNSPRT_QUIC) {
+    if(conn->httpversion < 20) { /* unless the connection is re-used and
+                                    already http2 */
+      switch(conn->negnpn) {
+      case CURL_HTTP_VERSION_2:
+        conn->httpversion = 20; /* we know we're on HTTP/2 now */
+
+        result = Curl_http2_switched(conn, NULL, 0);
+        if(result)
+          return result;
+        break;
+      case CURL_HTTP_VERSION_1_1:
+        /* continue with HTTP/1.1 when explicitly requested */
+        break;
+      default:
+        /* Check if user wants to use HTTP/2 with clear TCP*/
+#ifdef USE_NGHTTP2
+        if(conn->data->set.httpversion ==
+           CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE) {
+          if(conn->bits.httpproxy && !conn->bits.tunnel_proxy) {
+            /* We don't support HTTP/2 proxies yet. Also it's debatable
+               whether or not this setting should apply to HTTP/2 proxies. */
+            infof(data, "Ignoring HTTP/2 prior knowledge due to proxy\n");
+            break;
+          }
+
+          DEBUGF(infof(data, "HTTP/2 over clean TCP\n"));
+          conn->httpversion = 20;
+
+          result = Curl_http2_switched(conn, NULL, 0);
+          if(result)
+            return result;
+        }
+#endif
+        break;
+      }
+    }
+    else {
+      /* prepare for a http2 request */
+      result = Curl_http2_setup(conn);
+      if(result)
+        return result;
+    }
+  }
+  http = data->req.protop;
+  DEBUGASSERT(http);
+
+  if(!data->state.this_is_a_follow) {
+    /* Free to avoid leaking memory on multiple requests*/
+    free(data->state.first_host);
+
+    data->state.first_host = strdup(conn->host.name);
+    if(!data->state.first_host)
+      return CURLE_OUT_OF_MEMORY;
+
+    data->state.first_remote_port = conn->remote_port;
+  }
+
+  if((conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_FTP)) &&
+     data->set.upload) {
+    httpreq = HTTPREQ_PUT;
+  }
+
+  /* Now set the 'request' pointer to the proper request string */
+  if(data->set.str[STRING_CUSTOMREQUEST])
+    request = data->set.str[STRING_CUSTOMREQUEST];
+  else {
+    if(data->set.opt_no_body)
+      request = "HEAD";
+    else {
+      DEBUGASSERT((httpreq > HTTPREQ_NONE) && (httpreq < HTTPREQ_LAST));
+      switch(httpreq) {
+      case HTTPREQ_POST:
+      case HTTPREQ_POST_FORM:
+      case HTTPREQ_POST_MIME:
+        request = "POST";
+        break;
+      case HTTPREQ_PUT:
+        request = "PUT";
+        break;
+      case HTTPREQ_OPTIONS:
+        request = "OPTIONS";
+        break;
+      default: /* this should never happen */
+      case HTTPREQ_GET:
+        request = "GET";
+        break;
+      case HTTPREQ_HEAD:
+        request = "HEAD";
+        break;
+      }
+    }
+  }
+
+  /* The User-Agent string might have been allocated in url.c already, because
+     it might have been used in the proxy connect, but if we have got a header
+     with the user-agent string specified, we erase the previously made string
+     here. */
+  if(Curl_checkheaders(conn, "User-Agent")) {
+    free(conn->allocptr.uagent);
+    conn->allocptr.uagent = NULL;
+  }
+
+  /* setup the authentication headers */
+  {
+    char *pq = NULL;
+    if(query && *query) {
+      pq = aprintf("%s?%s", path, query);
+      if(!pq)
+        return CURLE_OUT_OF_MEMORY;
+    }
+    result = Curl_http_output_auth(conn, request, (pq ? pq : path), FALSE);
+    free(pq);
+    if(result)
+      return result;
+  }
+
+  if(((data->state.authhost.multipass && !data->state.authhost.done)
+      || (data->state.authproxy.multipass && !data->state.authproxy.done)) &&
+     (httpreq != HTTPREQ_GET) &&
+     (httpreq != HTTPREQ_HEAD)) {
+    /* Auth is required and we are not authenticated yet. Make a PUT or POST
+       with content-length zero as a "probe". */
+    conn->bits.authneg = TRUE;
+  }
+  else
+    conn->bits.authneg = FALSE;
+
+  Curl_safefree(conn->allocptr.ref);
+  if(data->change.referer && !Curl_checkheaders(conn, "Referer")) {
+    conn->allocptr.ref = aprintf("Referer: %s\r\n", data->change.referer);
+    if(!conn->allocptr.ref)
+      return CURLE_OUT_OF_MEMORY;
+  }
+  else
+    conn->allocptr.ref = NULL;
+
+#if !defined(CURL_DISABLE_COOKIES)
+  if(data->set.str[STRING_COOKIE] && !Curl_checkheaders(conn, "Cookie"))
+    addcookies = data->set.str[STRING_COOKIE];
+#endif
+
+  if(!Curl_checkheaders(conn, "Accept-Encoding") &&
+     data->set.str[STRING_ENCODING]) {
+    Curl_safefree(conn->allocptr.accept_encoding);
+    conn->allocptr.accept_encoding =
+      aprintf("Accept-Encoding: %s\r\n", data->set.str[STRING_ENCODING]);
+    if(!conn->allocptr.accept_encoding)
+      return CURLE_OUT_OF_MEMORY;
+  }
+  else {
+    Curl_safefree(conn->allocptr.accept_encoding);
+    conn->allocptr.accept_encoding = NULL;
+  }
+
+#ifdef HAVE_LIBZ
+  /* we only consider transfer-encoding magic if libz support is built-in */
+
+  if(!Curl_checkheaders(conn, "TE") &&
+     data->set.http_transfer_encoding) {
+    /* When we are to insert a TE: header in the request, we must also insert
+       TE in a Connection: header, so we need to merge the custom provided
+       Connection: header and prevent the original to get sent. Note that if
+       the user has inserted his/hers own TE: header we don't do this magic
+       but then assume that the user will handle it all! */
+    char *cptr = Curl_checkheaders(conn, "Connection");
+#define TE_HEADER "TE: gzip\r\n"
+
+    Curl_safefree(conn->allocptr.te);
+
+    if(cptr) {
+      cptr = Curl_copy_header_value(cptr);
+      if(!cptr)
+        return CURLE_OUT_OF_MEMORY;
+    }
+
+    /* Create the (updated) Connection: header */
+    conn->allocptr.te = aprintf("Connection: %s%sTE\r\n" TE_HEADER,
+                                cptr ? cptr : "", (cptr && *cptr) ? ", ":"");
+
+    free(cptr);
+    if(!conn->allocptr.te)
+      return CURLE_OUT_OF_MEMORY;
+  }
+#endif
+
+  switch(httpreq) {
+  case HTTPREQ_POST_MIME:
+    http->sendit = &data->set.mimepost;
+    break;
+  case HTTPREQ_POST_FORM:
+    /* Convert the form structure into a mime structure. */
+    Curl_mime_cleanpart(&http->form);
+    result = Curl_getformdata(data, &http->form, data->set.httppost,
+                              data->state.fread_func);
+    if(result)
+      return result;
+    http->sendit = &http->form;
+    break;
+  default:
+    http->sendit = NULL;
+  }
+
+#ifndef CURL_DISABLE_MIME
+  if(http->sendit) {
+    const char *cthdr = Curl_checkheaders(conn, "Content-Type");
+
+    /* Read and seek body only. */
+    http->sendit->flags |= MIME_BODY_ONLY;
+
+    /* Prepare the mime structure headers & set content type. */
+
+    if(cthdr)
+      for(cthdr += 13; *cthdr == ' '; cthdr++)
+        ;
+    else if(http->sendit->kind == MIMEKIND_MULTIPART)
+      cthdr = "multipart/form-data";
+
+    curl_mime_headers(http->sendit, data->set.headers, 0);
+    result = Curl_mime_prepare_headers(http->sendit, cthdr,
+                                       NULL, MIMESTRATEGY_FORM);
+    curl_mime_headers(http->sendit, NULL, 0);
+    if(!result)
+      result = Curl_mime_rewind(http->sendit);
+    if(result)
+      return result;
+    http->postsize = Curl_mime_size(http->sendit);
+  }
+#endif
+
+  ptr = Curl_checkheaders(conn, "Transfer-Encoding");
+  if(ptr) {
+    /* Some kind of TE is requested, check if 'chunked' is chosen */
+    data->req.upload_chunky =
+      Curl_compareheader(ptr, "Transfer-Encoding:", "chunked");
+  }
+  else {
+    if((conn->handler->protocol & PROTO_FAMILY_HTTP) &&
+       (((httpreq == HTTPREQ_POST_MIME || httpreq == HTTPREQ_POST_FORM) &&
+         http->postsize < 0) ||
+        ((data->set.upload || httpreq == HTTPREQ_POST) &&
+         data->state.infilesize == -1))) {
+      if(conn->bits.authneg)
+        /* don't enable chunked during auth neg */
+        ;
+      else if(use_http_1_1plus(data, conn)) {
+        if(conn->httpversion < 20)
+          /* HTTP, upload, unknown file size and not HTTP 1.0 */
+          data->req.upload_chunky = TRUE;
+      }
+      else {
+        failf(data, "Chunky upload is not supported by HTTP 1.0");
+        return CURLE_UPLOAD_FAILED;
+      }
+    }
+    else {
+      /* else, no chunky upload */
+      data->req.upload_chunky = FALSE;
+    }
+
+    if(data->req.upload_chunky)
+      te = "Transfer-Encoding: chunked\r\n";
+  }
+
+  Curl_safefree(conn->allocptr.host);
+
+  ptr = Curl_checkheaders(conn, "Host");
+  if(ptr && (!data->state.this_is_a_follow ||
+             strcasecompare(data->state.first_host, conn->host.name))) {
+#if !defined(CURL_DISABLE_COOKIES)
+    /* If we have a given custom Host: header, we extract the host name in
+       order to possibly use it for cookie reasons later on. We only allow the
+       custom Host: header if this is NOT a redirect, as setting Host: in the
+       redirected request is being out on thin ice. Except if the host name
+       is the same as the first one! */
+    char *cookiehost = Curl_copy_header_value(ptr);
+    if(!cookiehost)
+      return CURLE_OUT_OF_MEMORY;
+    if(!*cookiehost)
+      /* ignore empty data */
+      free(cookiehost);
+    else {
+      /* If the host begins with '[', we start searching for the port after
+         the bracket has been closed */
+      if(*cookiehost == '[') {
+        char *closingbracket;
+        /* since the 'cookiehost' is an allocated memory area that will be
+           freed later we cannot simply increment the pointer */
+        memmove(cookiehost, cookiehost + 1, strlen(cookiehost) - 1);
+        closingbracket = strchr(cookiehost, ']');
+        if(closingbracket)
+          *closingbracket = 0;
+      }
+      else {
+        int startsearch = 0;
+        char *colon = strchr(cookiehost + startsearch, ':');
+        if(colon)
+          *colon = 0; /* The host must not include an embedded port number */
+      }
+      Curl_safefree(conn->allocptr.cookiehost);
+      conn->allocptr.cookiehost = cookiehost;
+    }
+#endif
+
+    if(strcmp("Host:", ptr)) {
+      conn->allocptr.host = aprintf("Host:%s\r\n", &ptr[5]);
+      if(!conn->allocptr.host)
+        return CURLE_OUT_OF_MEMORY;
+    }
+    else
+      /* when clearing the header */
+      conn->allocptr.host = NULL;
+  }
+  else {
+    /* When building Host: headers, we must put the host name within
+       [brackets] if the host name is a plain IPv6-address. RFC2732-style. */
+
+    if(((conn->given->protocol&CURLPROTO_HTTPS) &&
+        (conn->remote_port == PORT_HTTPS)) ||
+       ((conn->given->protocol&CURLPROTO_HTTP) &&
+        (conn->remote_port == PORT_HTTP)) )
+      /* if(HTTPS on port 443) OR (HTTP on port 80) then don't include
+         the port number in the host string */
+      conn->allocptr.host = aprintf("Host: %s%s%s\r\n",
+                                    conn->bits.ipv6_ip?"[":"",
+                                    host,
+                                    conn->bits.ipv6_ip?"]":"");
+    else
+      conn->allocptr.host = aprintf("Host: %s%s%s:%d\r\n",
+                                    conn->bits.ipv6_ip?"[":"",
+                                    host,
+                                    conn->bits.ipv6_ip?"]":"",
+                                    conn->remote_port);
+
+    if(!conn->allocptr.host)
+      /* without Host: we can't make a nice request */
+      return CURLE_OUT_OF_MEMORY;
+  }
+
+#ifndef CURL_DISABLE_PROXY
+  if(conn->bits.httpproxy && !conn->bits.tunnel_proxy) {
+    /* Using a proxy but does not tunnel through it */
+
+    /* The path sent to the proxy is in fact the entire URL. But if the remote
+       host is a IDN-name, we must make sure that the request we produce only
+       uses the encoded host name! */
+
+    /* and no fragment part */
+    CURLUcode uc;
+    CURLU *h = curl_url_dup(data->state.uh);
+    if(!h)
+      return CURLE_OUT_OF_MEMORY;
+
+    if(conn->host.dispname != conn->host.name) {
+      uc = curl_url_set(h, CURLUPART_HOST, conn->host.name, 0);
+      if(uc) {
+        curl_url_cleanup(h);
+        return CURLE_OUT_OF_MEMORY;
+      }
+    }
+    uc = curl_url_set(h, CURLUPART_FRAGMENT, NULL, 0);
+    if(uc) {
+      curl_url_cleanup(h);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    if(strcasecompare("http", data->state.up.scheme)) {
+      /* when getting HTTP, we don't want the userinfo the URL */
+      uc = curl_url_set(h, CURLUPART_USER, NULL, 0);
+      if(uc) {
+        curl_url_cleanup(h);
+        return CURLE_OUT_OF_MEMORY;
+      }
+      uc = curl_url_set(h, CURLUPART_PASSWORD, NULL, 0);
+      if(uc) {
+        curl_url_cleanup(h);
+        return CURLE_OUT_OF_MEMORY;
+      }
+    }
+    /* Extract the the URL to use in the request. Store in STRING_TEMP_URL for
+       clean-up reasons if the function returns before the free() further
+       down. */
+    uc = curl_url_get(h, CURLUPART_URL, &data->set.str[STRING_TEMP_URL], 0);
+    if(uc) {
+      curl_url_cleanup(h);
+      return CURLE_OUT_OF_MEMORY;
+    }
+
+    curl_url_cleanup(h);
+
+    if(strcasecompare("ftp", data->state.up.scheme)) {
+      if(data->set.proxy_transfer_mode) {
+        /* when doing ftp, append ;type=<a|i> if not present */
+        char *type = strstr(path, ";type=");
+        if(type && type[6] && type[7] == 0) {
+          switch(Curl_raw_toupper(type[6])) {
+          case 'A':
+          case 'D':
+          case 'I':
+            break;
+          default:
+            type = NULL;
+          }
+        }
+        if(!type) {
+          char *p = ftp_typecode;
+          /* avoid sending invalid URLs like ftp://example.com;type=i if the
+           * user specified ftp://example.com without the slash */
+          if(!*data->state.up.path && path[strlen(path) - 1] != '/') {
+            *p++ = '/';
+          }
+          msnprintf(p, sizeof(ftp_typecode) - 1, ";type=%c",
+                    data->set.prefer_ascii ? 'a' : 'i');
+        }
+      }
+      if(conn->bits.user_passwd && !conn->bits.userpwd_in_url)
+        paste_ftp_userpwd = TRUE;
+    }
+  }
+#endif /* CURL_DISABLE_PROXY */
+
+  http->p_accept = Curl_checkheaders(conn, "Accept")?NULL:"Accept: */*\r\n";
+
+  if((HTTPREQ_POST == httpreq || HTTPREQ_PUT == httpreq) &&
+     data->state.resume_from) {
+    /**********************************************************************
+     * Resuming upload in HTTP means that we PUT or POST and that we have
+     * got a resume_from value set. The resume value has already created
+     * a Range: header that will be passed along. We need to "fast forward"
+     * the file the given number of bytes and decrease the assume upload
+     * file size before we continue this venture in the dark lands of HTTP.
+     * Resuming mime/form posting at an offset > 0 has no sense and is ignored.
+     *********************************************************************/
+
+    if(data->state.resume_from < 0) {
+      /*
+       * This is meant to get the size of the present remote-file by itself.
+       * We don't support this now. Bail out!
+       */
+      data->state.resume_from = 0;
+    }
+
+    if(data->state.resume_from && !data->state.this_is_a_follow) {
+      /* do we still game? */
+
+      /* Now, let's read off the proper amount of bytes from the
+         input. */
+      int seekerr = CURL_SEEKFUNC_CANTSEEK;
+      if(conn->seek_func) {
+        Curl_set_in_callback(data, true);
+        seekerr = conn->seek_func(conn->seek_client, data->state.resume_from,
+                                  SEEK_SET);
+        Curl_set_in_callback(data, false);
+      }
+
+      if(seekerr != CURL_SEEKFUNC_OK) {
+        curl_off_t passed = 0;
+
+        if(seekerr != CURL_SEEKFUNC_CANTSEEK) {
+          failf(data, "Could not seek stream");
+          return CURLE_READ_ERROR;
+        }
+        /* when seekerr == CURL_SEEKFUNC_CANTSEEK (can't seek to offset) */
+        do {
+          size_t readthisamountnow =
+            (data->state.resume_from - passed > data->set.buffer_size) ?
+            (size_t)data->set.buffer_size :
+            curlx_sotouz(data->state.resume_from - passed);
+
+          size_t actuallyread =
+            data->state.fread_func(data->state.buffer, 1, readthisamountnow,
+                                   data->state.in);
+
+          passed += actuallyread;
+          if((actuallyread == 0) || (actuallyread > readthisamountnow)) {
+            /* this checks for greater-than only to make sure that the
+               CURL_READFUNC_ABORT return code still aborts */
+            failf(data, "Could only read %" CURL_FORMAT_CURL_OFF_T
+                  " bytes from the input", passed);
+            return CURLE_READ_ERROR;
+          }
+        } while(passed < data->state.resume_from);
+      }
+
+      /* now, decrease the size of the read */
+      if(data->state.infilesize>0) {
+        data->state.infilesize -= data->state.resume_from;
+
+        if(data->state.infilesize <= 0) {
+          failf(data, "File already completely uploaded");
+          return CURLE_PARTIAL_FILE;
+        }
+      }
+      /* we've passed, proceed as normal */
+    }
+  }
+  if(data->state.use_range) {
+    /*
+     * A range is selected. We use different headers whether we're downloading
+     * or uploading and we always let customized headers override our internal
+     * ones if any such are specified.
+     */
+    if(((httpreq == HTTPREQ_GET) || (httpreq == HTTPREQ_HEAD)) &&
+       !Curl_checkheaders(conn, "Range")) {
+      /* if a line like this was already allocated, free the previous one */
+      free(conn->allocptr.rangeline);
+      conn->allocptr.rangeline = aprintf("Range: bytes=%s\r\n",
+                                         data->state.range);
+    }
+    else if((httpreq == HTTPREQ_POST || httpreq == HTTPREQ_PUT) &&
+            !Curl_checkheaders(conn, "Content-Range")) {
+
+      /* if a line like this was already allocated, free the previous one */
+      free(conn->allocptr.rangeline);
+
+      if(data->set.set_resume_from < 0) {
+        /* Upload resume was asked for, but we don't know the size of the
+           remote part so we tell the server (and act accordingly) that we
+           upload the whole file (again) */
+        conn->allocptr.rangeline =
+          aprintf("Content-Range: bytes 0-%" CURL_FORMAT_CURL_OFF_T
+                  "/%" CURL_FORMAT_CURL_OFF_T "\r\n",
+                  data->state.infilesize - 1, data->state.infilesize);
+
+      }
+      else if(data->state.resume_from) {
+        /* This is because "resume" was selected */
+        curl_off_t total_expected_size =
+          data->state.resume_from + data->state.infilesize;
+        conn->allocptr.rangeline =
+          aprintf("Content-Range: bytes %s%" CURL_FORMAT_CURL_OFF_T
+                  "/%" CURL_FORMAT_CURL_OFF_T "\r\n",
+                  data->state.range, total_expected_size-1,
+                  total_expected_size);
+      }
+      else {
+        /* Range was selected and then we just pass the incoming range and
+           append total size */
+        conn->allocptr.rangeline =
+          aprintf("Content-Range: bytes %s/%" CURL_FORMAT_CURL_OFF_T "\r\n",
+                  data->state.range, data->state.infilesize);
+      }
+      if(!conn->allocptr.rangeline)
+        return CURLE_OUT_OF_MEMORY;
+    }
+  }
+
+  httpstring = get_http_string(data, conn);
+
+  /* initialize a dynamic send-buffer */
+  req_buffer = Curl_add_buffer_init();
+
+  if(!req_buffer)
+    return CURLE_OUT_OF_MEMORY;
+
+  /* add the main request stuff */
+  /* GET/HEAD/POST/PUT */
+  result = Curl_add_bufferf(&req_buffer, "%s ", request);
+  if(result)
+    return result;
+
+  if(data->set.str[STRING_TARGET]) {
+    path = data->set.str[STRING_TARGET];
+    query = NULL;
+  }
+
+#ifndef CURL_DISABLE_PROXY
+  /* url */
+  if(conn->bits.httpproxy && !conn->bits.tunnel_proxy) {
+    char *url = data->set.str[STRING_TEMP_URL];
+    result = Curl_add_buffer(&req_buffer, url, strlen(url));
+    Curl_safefree(data->set.str[STRING_TEMP_URL]);
+  }
+  else
+#endif
+  if(paste_ftp_userpwd)
+    result = Curl_add_bufferf(&req_buffer, "ftp://%s:%s@%s",
+                              conn->user, conn->passwd,
+                              path + sizeof("ftp://") - 1);
+  else {
+    result = Curl_add_buffer(&req_buffer, path, strlen(path));
+    if(result)
+      return result;
+    if(query)
+      result = Curl_add_bufferf(&req_buffer, "?%s", query);
+  }
+  if(result)
+    return result;
+
+#ifdef USE_ALTSVC
+  if(conn->bits.altused && !Curl_checkheaders(conn, "Alt-Used")) {
+    altused = aprintf("Alt-Used: %s:%d\r\n",
+                      conn->conn_to_host.name, conn->conn_to_port);
+    if(!altused)
+      return CURLE_OUT_OF_MEMORY;
+  }
+#endif
+  result =
+    Curl_add_bufferf(&req_buffer,
+                     "%s" /* ftp typecode (;type=x) */
+                     " HTTP/%s\r\n" /* HTTP version */
+                     "%s" /* host */
+                     "%s" /* proxyuserpwd */
+                     "%s" /* userpwd */
+                     "%s" /* range */
+                     "%s" /* user agent */
+                     "%s" /* accept */
+                     "%s" /* TE: */
+                     "%s" /* accept-encoding */
+                     "%s" /* referer */
+                     "%s" /* Proxy-Connection */
+                     "%s" /* transfer-encoding */
+                     "%s",/* Alt-Used */
+
+                     ftp_typecode,
+                     httpstring,
+                     (conn->allocptr.host?conn->allocptr.host:""),
+                     conn->allocptr.proxyuserpwd?
+                     conn->allocptr.proxyuserpwd:"",
+                     conn->allocptr.userpwd?conn->allocptr.userpwd:"",
+                     (data->state.use_range && conn->allocptr.rangeline)?
+                     conn->allocptr.rangeline:"",
+                     (data->set.str[STRING_USERAGENT] &&
+                      *data->set.str[STRING_USERAGENT] &&
+                      conn->allocptr.uagent)?
+                     conn->allocptr.uagent:"",
+                     http->p_accept?http->p_accept:"",
+                     conn->allocptr.te?conn->allocptr.te:"",
+                     (data->set.str[STRING_ENCODING] &&
+                      *data->set.str[STRING_ENCODING] &&
+                      conn->allocptr.accept_encoding)?
+                     conn->allocptr.accept_encoding:"",
+                     (data->change.referer && conn->allocptr.ref)?
+                     conn->allocptr.ref:"" /* Referer: <data> */,
+                     (conn->bits.httpproxy &&
+                      !conn->bits.tunnel_proxy &&
+                      !Curl_checkProxyheaders(conn, "Proxy-Connection"))?
+                     "Proxy-Connection: Keep-Alive\r\n":"",
+                     te,
+                     altused ? altused : ""
+      );
+
+  /* clear userpwd and proxyuserpwd to avoid re-using old credentials
+   * from re-used connections */
+  Curl_safefree(conn->allocptr.userpwd);
+  Curl_safefree(conn->allocptr.proxyuserpwd);
+  free(altused);
+
+  if(result)
+    return result;
+
+  if(!(conn->handler->flags&PROTOPT_SSL) &&
+     conn->httpversion != 20 &&
+     (data->set.httpversion == CURL_HTTP_VERSION_2)) {
+    /* append HTTP2 upgrade magic stuff to the HTTP request if it isn't done
+       over SSL */
+    result = Curl_http2_request_upgrade(req_buffer, conn);
+    if(result)
+      return result;
+  }
+
+#if !defined(CURL_DISABLE_COOKIES)
+  if(data->cookies || addcookies) {
+    struct Cookie *co = NULL; /* no cookies from start */
+    int count = 0;
+
+    if(data->cookies) {
+      Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);
+      co = Curl_cookie_getlist(data->cookies,
+                               conn->allocptr.cookiehost?
+                               conn->allocptr.cookiehost:host,
+                               data->state.up.path,
+                               (conn->handler->protocol&CURLPROTO_HTTPS)?
+                               TRUE:FALSE);
+      Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
+    }
+    if(co) {
+      struct Cookie *store = co;
+      /* now loop through all cookies that matched */
+      while(co) {
+        if(co->value) {
+          if(0 == count) {
+            result = Curl_add_bufferf(&req_buffer, "Cookie: ");
+            if(result)
+              break;
+          }
+          result = Curl_add_bufferf(&req_buffer,
+                                    "%s%s=%s", count?"; ":"",
+                                    co->name, co->value);
+          if(result)
+            break;
+          count++;
+        }
+        co = co->next; /* next cookie please */
+      }
+      Curl_cookie_freelist(store);
+    }
+    if(addcookies && !result) {
+      if(!count)
+        result = Curl_add_bufferf(&req_buffer, "Cookie: ");
+      if(!result) {
+        result = Curl_add_bufferf(&req_buffer, "%s%s", count?"; ":"",
+                                  addcookies);
+        count++;
+      }
+    }
+    if(count && !result)
+      result = Curl_add_buffer(&req_buffer, "\r\n", 2);
+
+    if(result)
+      return result;
+  }
+#endif
+
+  result = Curl_add_timecondition(conn, req_buffer);
+  if(result)
+    return result;
+
+  result = Curl_add_custom_headers(conn, FALSE, req_buffer);
+  if(result)
+    return result;
+
+  http->postdata = NULL;  /* nothing to post at this point */
+  Curl_pgrsSetUploadSize(data, -1); /* upload size is unknown atm */
+
+  /* If 'authdone' is FALSE, we must not set the write socket index to the
+     Curl_transfer() call below, as we're not ready to actually upload any
+     data yet. */
+
+  switch(httpreq) {
+
+  case HTTPREQ_PUT: /* Let's PUT the data to the server! */
+
+    if(conn->bits.authneg)
+      postsize = 0;
+    else
+      postsize = data->state.infilesize;
+
+    if((postsize != -1) && !data->req.upload_chunky &&
+       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length"))) {
+      /* only add Content-Length if not uploading chunked */
+      result = Curl_add_bufferf(&req_buffer,
+                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
+                                "\r\n", postsize);
+      if(result)
+        return result;
+    }
+
+    if(postsize != 0) {
+      result = expect100(data, conn, req_buffer);
+      if(result)
+        return result;
+    }
+
+    result = Curl_add_buffer(&req_buffer, "\r\n", 2); /* end of headers */
+    if(result)
+      return result;
+
+    /* set the upload size to the progress meter */
+    Curl_pgrsSetUploadSize(data, postsize);
+
+    /* this sends the buffer and frees all the buffer resources */
+    result = Curl_add_buffer_send(&req_buffer, conn,
+                                  &data->info.request_size, 0, FIRSTSOCKET);
+    if(result)
+      failf(data, "Failed sending PUT request");
+    else
+      /* prepare for transfer */
+      Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE,
+                          postsize?FIRSTSOCKET:-1);
+    if(result)
+      return result;
+    break;
+
+  case HTTPREQ_POST_FORM:
+  case HTTPREQ_POST_MIME:
+    /* This is form posting using mime data. */
+    if(conn->bits.authneg) {
+      /* nothing to post! */
+      result = Curl_add_bufferf(&req_buffer, "Content-Length: 0\r\n\r\n");
+      if(result)
+        return result;
+
+      result = Curl_add_buffer_send(&req_buffer, conn,
+                                    &data->info.request_size, 0, FIRSTSOCKET);
+      if(result)
+        failf(data, "Failed sending POST request");
+      else
+        /* setup variables for the upcoming transfer */
+        Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE, -1);
+      break;
+    }
+
+    data->state.infilesize = postsize = http->postsize;
+
+    /* We only set Content-Length and allow a custom Content-Length if
+       we don't upload data chunked, as RFC2616 forbids us to set both
+       kinds of headers (Transfer-Encoding: chunked and Content-Length) */
+    if(postsize != -1 && !data->req.upload_chunky &&
+       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length"))) {
+      /* we allow replacing this header if not during auth negotiation,
+         although it isn't very wise to actually set your own */
+      result = Curl_add_bufferf(&req_buffer,
+                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
+                                "\r\n", postsize);
+      if(result)
+        return result;
+    }
+
+#ifndef CURL_DISABLE_MIME
+    /* Output mime-generated headers. */
+    {
+      struct curl_slist *hdr;
+
+      for(hdr = http->sendit->curlheaders; hdr; hdr = hdr->next) {
+        result = Curl_add_bufferf(&req_buffer, "%s\r\n", hdr->data);
+        if(result)
+          return result;
+      }
+    }
+#endif
+
+    /* For really small posts we don't use Expect: headers at all, and for
+       the somewhat bigger ones we allow the app to disable it. Just make
+       sure that the expect100header is always set to the preferred value
+       here. */
+    ptr = Curl_checkheaders(conn, "Expect");
+    if(ptr) {
+      data->state.expect100header =
+        Curl_compareheader(ptr, "Expect:", "100-continue");
+    }
+    else if(postsize > EXPECT_100_THRESHOLD || postsize < 0) {
+      result = expect100(data, conn, req_buffer);
+      if(result)
+        return result;
+    }
+    else
+      data->state.expect100header = FALSE;
+
+    /* make the request end in a true CRLF */
+    result = Curl_add_buffer(&req_buffer, "\r\n", 2);
+    if(result)
+      return result;
+
+    /* set the upload size to the progress meter */
+    Curl_pgrsSetUploadSize(data, postsize);
+
+    /* Read from mime structure. */
+    data->state.fread_func = (curl_read_callback) Curl_mime_read;
+    data->state.in = (void *) http->sendit;
+    http->sending = HTTPSEND_BODY;
+
+    /* this sends the buffer and frees all the buffer resources */
+    result = Curl_add_buffer_send(&req_buffer, conn,
+                                  &data->info.request_size, 0, FIRSTSOCKET);
+    if(result)
+      failf(data, "Failed sending POST request");
+    else
+      /* prepare for transfer */
+      Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE,
+                          postsize?FIRSTSOCKET:-1);
+    if(result)
+      return result;
+
+    break;
+
+  case HTTPREQ_POST:
+    /* this is the simple POST, using x-www-form-urlencoded style */
+
+    if(conn->bits.authneg)
+      postsize = 0;
+    else
+      /* the size of the post body */
+      postsize = data->state.infilesize;
+
+    /* We only set Content-Length and allow a custom Content-Length if
+       we don't upload data chunked, as RFC2616 forbids us to set both
+       kinds of headers (Transfer-Encoding: chunked and Content-Length) */
+    if((postsize != -1) && !data->req.upload_chunky &&
+       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length"))) {
+      /* we allow replacing this header if not during auth negotiation,
+         although it isn't very wise to actually set your own */
+      result = Curl_add_bufferf(&req_buffer,
+                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
+                                "\r\n", postsize);
+      if(result)
+        return result;
+    }
+
+    if(!Curl_checkheaders(conn, "Content-Type")) {
+      result = Curl_add_bufferf(&req_buffer,
+                                "Content-Type: application/"
+                                "x-www-form-urlencoded\r\n");
+      if(result)
+        return result;
+    }
+
+    /* For really small posts we don't use Expect: headers at all, and for
+       the somewhat bigger ones we allow the app to disable it. Just make
+       sure that the expect100header is always set to the preferred value
+       here. */
+    ptr = Curl_checkheaders(conn, "Expect");
+    if(ptr) {
+      data->state.expect100header =
+        Curl_compareheader(ptr, "Expect:", "100-continue");
+    }
+    else if(postsize > EXPECT_100_THRESHOLD || postsize < 0) {
+      result = expect100(data, conn, req_buffer);
+      if(result)
+        return result;
+    }
+    else
+      data->state.expect100header = FALSE;
+
+    if(data->set.postfields) {
+
+      /* In HTTP2, we send request body in DATA frame regardless of
+         its size. */
+      if(conn->httpversion != 20 &&
+         !data->state.expect100header &&
+         (postsize < MAX_INITIAL_POST_SIZE)) {
+        /* if we don't use expect: 100  AND
+           postsize is less than MAX_INITIAL_POST_SIZE
+
+           then append the post data to the HTTP request header. This limit
+           is no magic limit but only set to prevent really huge POSTs to
+           get the data duplicated with malloc() and family. */
+
+        result = Curl_add_buffer(&req_buffer, "\r\n", 2); /* end of headers! */
+        if(result)
+          return result;
+
+        if(!data->req.upload_chunky) {
+          /* We're not sending it 'chunked', append it to the request
+             already now to reduce the number if send() calls */
+          result = Curl_add_buffer(&req_buffer, data->set.postfields,
+                                   (size_t)postsize);
+          included_body = postsize;
+        }
+        else {
+          if(postsize) {
+            /* Append the POST data chunky-style */
+            result = Curl_add_bufferf(&req_buffer, "%x\r\n", (int)postsize);
+            if(!result) {
+              result = Curl_add_buffer(&req_buffer, data->set.postfields,
+                                       (size_t)postsize);
+              if(!result)
+                result = Curl_add_buffer(&req_buffer, "\r\n", 2);
+              included_body = postsize + 2;
+            }
+          }
+          if(!result)
+            result = Curl_add_buffer(&req_buffer, "\x30\x0d\x0a\x0d\x0a", 5);
+          /* 0  CR  LF  CR  LF */
+          included_body += 5;
+        }
+        if(result)
+          return result;
+        /* Make sure the progress information is accurate */
+        Curl_pgrsSetUploadSize(data, postsize);
+      }
+      else {
+        /* A huge POST coming up, do data separate from the request */
+        http->postsize = postsize;
+        http->postdata = data->set.postfields;
+
+        http->sending = HTTPSEND_BODY;
+
+        data->state.fread_func = (curl_read_callback)readmoredata;
+        data->state.in = (void *)conn;
+
+        /* set the upload size to the progress meter */
+        Curl_pgrsSetUploadSize(data, http->postsize);
+
+        result = Curl_add_buffer(&req_buffer, "\r\n", 2); /* end of headers! */
+        if(result)
+          return result;
+      }
+    }
+    else {
+      result = Curl_add_buffer(&req_buffer, "\r\n", 2); /* end of headers! */
+      if(result)
+        return result;
+
+      if(data->req.upload_chunky && conn->bits.authneg) {
+        /* Chunky upload is selected and we're negotiating auth still, send
+           end-of-data only */
+        result = Curl_add_buffer(&req_buffer,
+                                 "\x30\x0d\x0a\x0d\x0a", 5);
+        /* 0  CR  LF  CR  LF */
+        if(result)
+          return result;
+      }
+
+      else if(data->state.infilesize) {
+        /* set the upload size to the progress meter */
+        Curl_pgrsSetUploadSize(data, postsize?postsize:-1);
+
+        /* set the pointer to mark that we will send the post body using the
+           read callback, but only if we're not in authenticate
+           negotiation  */
+        if(!conn->bits.authneg) {
+          http->postdata = (char *)&http->postdata;
+          http->postsize = postsize;
+        }
+      }
+    }
+    /* issue the request */
+    result = Curl_add_buffer_send(&req_buffer, conn, &data->info.request_size,
+                                  (size_t)included_body, FIRSTSOCKET);
+
+    if(result)
+      failf(data, "Failed sending HTTP POST request");
+    else
+      Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE,
+                          http->postdata?FIRSTSOCKET:-1);
+    break;
+
+  default:
+    result = Curl_add_buffer(&req_buffer, "\r\n", 2);
+    if(result)
+      return result;
+
+    /* issue the request */
+    result = Curl_add_buffer_send(&req_buffer, conn,
+                                  &data->info.request_size, 0, FIRSTSOCKET);
+
+    if(result)
+      failf(data, "Failed sending HTTP request");
+    else
+      /* HTTP GET/HEAD download: */
+      Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE,
+                          http->postdata?FIRSTSOCKET:-1);
+  }
+  if(result)
+    return result;
+
+  if(data->req.writebytecount) {
+    /* if a request-body has been sent off, we make sure this progress is noted
+       properly */
+    Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
+    if(Curl_pgrsUpdate(conn))
+      result = CURLE_ABORTED_BY_CALLBACK;
+
+    if(data->req.writebytecount >= postsize) {
+      /* already sent the entire request body, mark the "upload" as
+         complete */
+      infof(data, "upload completely sent off: %" CURL_FORMAT_CURL_OFF_T
+            " out of %" CURL_FORMAT_CURL_OFF_T " bytes\n",
+            data->req.writebytecount, postsize);
+      data->req.upload_done = TRUE;
+      data->req.keepon &= ~KEEP_SEND; /* we're done writing */
+      data->req.exp100 = EXP100_SEND_DATA; /* already sent */
+      Curl_expire_done(data, EXPIRE_100_TIMEOUT);
+    }
+  }
+
+  if((conn->httpversion == 20) && data->req.upload_chunky)
+    /* upload_chunky was set above to set up the request in a chunky fashion,
+       but is disabled here again to avoid that the chunked encoded version is
+       actually used when sending the request body over h2 */
+    data->req.upload_chunky = FALSE;
+  return result;
+}
+
+typedef enum {
+  STATUS_UNKNOWN, /* not enough data to tell yet */
+  STATUS_DONE, /* a status line was read */
+  STATUS_BAD /* not a status line */
+} statusline;
+
+
+/* Check a string for a prefix. Check no more than 'len' bytes */
+static bool checkprefixmax(const char *prefix, const char *buffer, size_t len)
+{
+  size_t ch = CURLMIN(strlen(prefix), len);
+  return curl_strnequal(prefix, buffer, ch);
+}
+
+/*
+ * checkhttpprefix()
+ *
+ * Returns TRUE if member of the list matches prefix of string
+ */
+static statusline
+checkhttpprefix(struct Curl_easy *data,
+                const char *s, size_t len)
+{
+  struct curl_slist *head = data->set.http200aliases;
+  statusline rc = STATUS_BAD;
+  statusline onmatch = len >= 5? STATUS_DONE : STATUS_UNKNOWN;
+#ifdef CURL_DOES_CONVERSIONS
+  /* convert from the network encoding using a scratch area */
+  char *scratch = strdup(s);
+  if(NULL == scratch) {
+    failf(data, "Failed to allocate memory for conversion!");
+    return FALSE; /* can't return CURLE_OUT_OF_MEMORY so return FALSE */
+  }
+  if(CURLE_OK != Curl_convert_from_network(data, scratch, strlen(s) + 1)) {
+    /* Curl_convert_from_network calls failf if unsuccessful */
+    free(scratch);
+    return FALSE; /* can't return CURLE_foobar so return FALSE */
+  }
+  s = scratch;
+#endif /* CURL_DOES_CONVERSIONS */
+
+  while(head) {
+    if(checkprefixmax(head->data, s, len)) {
+      rc = onmatch;
+      break;
+    }
+    head = head->next;
+  }
+
+  if((rc != STATUS_DONE) && (checkprefixmax("HTTP/", s, len)))
+    rc = onmatch;
+
+#ifdef CURL_DOES_CONVERSIONS
+  free(scratch);
+#endif /* CURL_DOES_CONVERSIONS */
+  return rc;
+}
+
+#ifndef CURL_DISABLE_RTSP
+static statusline
+checkrtspprefix(struct Curl_easy *data,
+                const char *s, size_t len)
+{
+  statusline result = STATUS_BAD;
+  statusline onmatch = len >= 5? STATUS_DONE : STATUS_UNKNOWN;
+
+#ifdef CURL_DOES_CONVERSIONS
+  /* convert from the network encoding using a scratch area */
+  char *scratch = strdup(s);
+  if(NULL == scratch) {
+    failf(data, "Failed to allocate memory for conversion!");
+    return FALSE; /* can't return CURLE_OUT_OF_MEMORY so return FALSE */
+  }
+  if(CURLE_OK != Curl_convert_from_network(data, scratch, strlen(s) + 1)) {
+    /* Curl_convert_from_network calls failf if unsuccessful */
+    result = FALSE; /* can't return CURLE_foobar so return FALSE */
+  }
+  else if(checkprefixmax("RTSP/", scratch, len))
+    result = onmatch;
+  free(scratch);
+#else
+  (void)data; /* unused */
+  if(checkprefixmax("RTSP/", s, len))
+    result = onmatch;
+#endif /* CURL_DOES_CONVERSIONS */
+
+  return result;
+}
+#endif /* CURL_DISABLE_RTSP */
+
+static statusline
+checkprotoprefix(struct Curl_easy *data, struct connectdata *conn,
+                 const char *s, size_t len)
+{
+#ifndef CURL_DISABLE_RTSP
+  if(conn->handler->protocol & CURLPROTO_RTSP)
+    return checkrtspprefix(data, s, len);
+#else
+  (void)conn;
+#endif /* CURL_DISABLE_RTSP */
+
+  return checkhttpprefix(data, s, len);
+}
+
+/*
+ * header_append() copies a chunk of data to the end of the already received
+ * header. We make sure that the full string fit in the allocated header
+ * buffer, or else we enlarge it.
+ */
+static CURLcode header_append(struct Curl_easy *data,
+                              struct SingleRequest *k,
+                              size_t length)
+{
+  /* length is at most the size of a full read buffer, for which the upper
+     bound is CURL_MAX_READ_SIZE. There is thus no chance of overflow in this
+     calculation. */
+  size_t newsize = k->hbuflen + length;
+  if(newsize > CURL_MAX_HTTP_HEADER) {
+    /* The reason to have a max limit for this is to avoid the risk of a bad
+       server feeding libcurl with a never-ending header that will cause
+       reallocs infinitely */
+    failf(data, "Rejected %zu bytes header (max is %d)!", newsize,
+          CURL_MAX_HTTP_HEADER);
+    return CURLE_OUT_OF_MEMORY;
+  }
+  if(newsize >= data->state.headersize) {
+    /* We enlarge the header buffer as it is too small */
+    char *newbuff;
+    size_t hbufp_index;
+
+    newsize = CURLMAX((k->hbuflen + length) * 3 / 2, data->state.headersize*2);
+    hbufp_index = k->hbufp - data->state.headerbuff;
+    newbuff = realloc(data->state.headerbuff, newsize);
+    if(!newbuff) {
+      failf(data, "Failed to alloc memory for big header!");
+      return CURLE_OUT_OF_MEMORY;
+    }
+    data->state.headersize = newsize;
+    data->state.headerbuff = newbuff;
+    k->hbufp = data->state.headerbuff + hbufp_index;
+  }
+  memcpy(k->hbufp, k->str_start, length);
+  k->hbufp += length;
+  k->hbuflen += length;
+  *k->hbufp = 0;
+
+  return CURLE_OK;
+}
+
+static void print_http_error(struct Curl_easy *data)
+{
+  struct SingleRequest *k = &data->req;
+  char *beg = k->p;
+
+  /* make sure that data->req.p points to the HTTP status line */
+  if(!strncmp(beg, "HTTP", 4)) {
+
+    /* skip to HTTP status code */
+    beg = strchr(beg, ' ');
+    if(beg && *++beg) {
+
+      /* find trailing CR */
+      char end_char = '\r';
+      char *end = strchr(beg, end_char);
+      if(!end) {
+        /* try to find LF (workaround for non-compliant HTTP servers) */
+        end_char = '\n';
+        end = strchr(beg, end_char);
+      }
+
+      if(end) {
+        /* temporarily replace CR or LF by NUL and print the error message */
+        *end = '\0';
+        failf(data, "The requested URL returned error: %s", beg);
+
+        /* restore the previously replaced CR or LF */
+        *end = end_char;
+        return;
+      }
+    }
+  }
+
+  /* fall-back to printing the HTTP status code only */
+  failf(data, "The requested URL returned error: %d", k->httpcode);
+}
+
+/*
+ * Read any HTTP header lines from the server and pass them to the client app.
+ */
+CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,
+                                       struct connectdata *conn,
+                                       ssize_t *nread,
+                                       bool *stop_reading)
+{
+  CURLcode result;
+  struct SingleRequest *k = &data->req;
+  ssize_t onread = *nread;
+  char *ostr = k->str;
+
+  /* header line within buffer loop */
+  do {
+    size_t rest_length;
+    size_t full_length;
+    int writetype;
+
+    /* str_start is start of line within buf */
+    k->str_start = k->str;
+
+    /* data is in network encoding so use 0x0a instead of '\n' */
+    k->end_ptr = memchr(k->str_start, 0x0a, *nread);
+
+    if(!k->end_ptr) {
+      /* Not a complete header line within buffer, append the data to
+         the end of the headerbuff. */
+      result = header_append(data, k, *nread);
+      if(result)
+        return result;
+
+      if(!k->headerline) {
+        /* check if this looks like a protocol header */
+        statusline st = checkprotoprefix(data, conn, data->state.headerbuff,
+                                         k->hbuflen);
+        if(st == STATUS_BAD) {
+          /* this is not the beginning of a protocol first header line */
+          k->header = FALSE;
+          k->badheader = HEADER_ALLBAD;
+          streamclose(conn, "bad HTTP: No end-of-message indicator");
+          if(!data->set.http09_allowed) {
+            failf(data, "Received HTTP/0.9 when not allowed\n");
+            return CURLE_UNSUPPORTED_PROTOCOL;
+          }
+          break;
+        }
+      }
+
+      break; /* read more and try again */
+    }
+
+    /* decrease the size of the remaining (supposed) header line */
+    rest_length = (k->end_ptr - k->str) + 1;
+    *nread -= (ssize_t)rest_length;
+
+    k->str = k->end_ptr + 1; /* move past new line */
+
+    full_length = k->str - k->str_start;
+
+    result = header_append(data, k, full_length);
+    if(result)
+      return result;
+
+    k->end_ptr = k->hbufp;
+    k->p = data->state.headerbuff;
+
+    /****
+     * We now have a FULL header line that p points to
+     *****/
+
+    if(!k->headerline) {
+      /* the first read header */
+      statusline st = checkprotoprefix(data, conn, data->state.headerbuff,
+                                       k->hbuflen);
+      if(st == STATUS_BAD) {
+        streamclose(conn, "bad HTTP: No end-of-message indicator");
+        /* this is not the beginning of a protocol first header line */
+        if(!data->set.http09_allowed) {
+          failf(data, "Received HTTP/0.9 when not allowed\n");
+          return CURLE_UNSUPPORTED_PROTOCOL;
+        }
+        k->header = FALSE;
+        if(*nread)
+          /* since there's more, this is a partial bad header */
+          k->badheader = HEADER_PARTHEADER;
+        else {
+          /* this was all we read so it's all a bad header */
+          k->badheader = HEADER_ALLBAD;
+          *nread = onread;
+          k->str = ostr;
+          return CURLE_OK;
+        }
+        break;
+      }
+    }
+
+    /* headers are in network encoding so
+       use 0x0a and 0x0d instead of '\n' and '\r' */
+    if((0x0a == *k->p) || (0x0d == *k->p)) {
+      size_t headerlen;
+      /* Zero-length header line means end of headers! */
+
+#ifdef CURL_DOES_CONVERSIONS
+      if(0x0d == *k->p) {
+        *k->p = '\r'; /* replace with CR in host encoding */
+        k->p++;       /* pass the CR byte */
+      }
+      if(0x0a == *k->p) {
+        *k->p = '\n'; /* replace with LF in host encoding */
+        k->p++;       /* pass the LF byte */
+      }
+#else
+      if('\r' == *k->p)
+        k->p++; /* pass the \r byte */
+      if('\n' == *k->p)
+        k->p++; /* pass the \n byte */
+#endif /* CURL_DOES_CONVERSIONS */
+
+      if(100 <= k->httpcode && 199 >= k->httpcode) {
+        /* "A user agent MAY ignore unexpected 1xx status responses." */
+        switch(k->httpcode) {
+        case 100:
+          /*
+           * We have made a HTTP PUT or POST and this is 1.1-lingo
+           * that tells us that the server is OK with this and ready
+           * to receive the data.
+           * However, we'll get more headers now so we must get
+           * back into the header-parsing state!
+           */
+          k->header = TRUE;
+          k->headerline = 0; /* restart the header line counter */
+
+          /* if we did wait for this do enable write now! */
+          if(k->exp100 > EXP100_SEND_DATA) {
+            k->exp100 = EXP100_SEND_DATA;
+            k->keepon |= KEEP_SEND;
+            Curl_expire_done(data, EXPIRE_100_TIMEOUT);
+          }
+          break;
+        case 101:
+          /* Switching Protocols */
+          if(k->upgr101 == UPGR101_REQUESTED) {
+            /* Switching to HTTP/2 */
+            infof(data, "Received 101\n");
+            k->upgr101 = UPGR101_RECEIVED;
+
+            /* we'll get more headers (HTTP/2 response) */
+            k->header = TRUE;
+            k->headerline = 0; /* restart the header line counter */
+
+            /* switch to http2 now. The bytes after response headers
+               are also processed here, otherwise they are lost. */
+            result = Curl_http2_switched(conn, k->str, *nread);
+            if(result)
+              return result;
+            *nread = 0;
+          }
+          else {
+            /* Switching to another protocol (e.g. WebSocket) */
+            k->header = FALSE; /* no more header to parse! */
+          }
+          break;
+        default:
+          /* the status code 1xx indicates a provisional response, so
+             we'll get another set of headers */
+          k->header = TRUE;
+          k->headerline = 0; /* restart the header line counter */
+          break;
+        }
+      }
+      else {
+        k->header = FALSE; /* no more header to parse! */
+
+        if((k->size == -1) && !k->chunk && !conn->bits.close &&
+           (conn->httpversion == 11) &&
+           !(conn->handler->protocol & CURLPROTO_RTSP) &&
+           data->set.httpreq != HTTPREQ_HEAD) {
+          /* On HTTP 1.1, when connection is not to get closed, but no
+             Content-Length nor Transfer-Encoding chunked have been
+             received, according to RFC2616 section 4.4 point 5, we
+             assume that the server will close the connection to
+             signal the end of the document. */
+          infof(data, "no chunk, no close, no size. Assume close to "
+                "signal end\n");
+          streamclose(conn, "HTTP: No end-of-message indicator");
+        }
+      }
+
+      /* At this point we have some idea about the fate of the connection.
+         If we are closing the connection it may result auth failure. */
+#if defined(USE_NTLM)
+      if(conn->bits.close &&
+         (((data->req.httpcode == 401) &&
+           (conn->http_ntlm_state == NTLMSTATE_TYPE2)) ||
+          ((data->req.httpcode == 407) &&
+           (conn->proxy_ntlm_state == NTLMSTATE_TYPE2)))) {
+        infof(data, "Connection closure while negotiating auth (HTTP 1.0?)\n");
+        data->state.authproblem = TRUE;
+      }
+#endif
+#if defined(USE_SPNEGO)
+      if(conn->bits.close &&
+        (((data->req.httpcode == 401) &&
+          (conn->http_negotiate_state == GSS_AUTHRECV)) ||
+         ((data->req.httpcode == 407) &&
+          (conn->proxy_negotiate_state == GSS_AUTHRECV)))) {
+        infof(data, "Connection closure while negotiating auth (HTTP 1.0?)\n");
+        data->state.authproblem = TRUE;
+      }
+      if((conn->http_negotiate_state == GSS_AUTHDONE) &&
+         (data->req.httpcode != 401)) {
+        conn->http_negotiate_state = GSS_AUTHSUCC;
+      }
+      if((conn->proxy_negotiate_state == GSS_AUTHDONE) &&
+         (data->req.httpcode != 407)) {
+        conn->proxy_negotiate_state = GSS_AUTHSUCC;
+      }
+#endif
+      /*
+       * When all the headers have been parsed, see if we should give
+       * up and return an error.
+       */
+      if(http_should_fail(conn)) {
+        failf(data, "The requested URL returned error: %d",
+              k->httpcode);
+        return CURLE_HTTP_RETURNED_ERROR;
+      }
+
+      /* now, only output this if the header AND body are requested:
+       */
+      writetype = CLIENTWRITE_HEADER;
+      if(data->set.include_header)
+        writetype |= CLIENTWRITE_BODY;
+
+      headerlen = k->p - data->state.headerbuff;
+
+      result = Curl_client_write(conn, writetype,
+                                 data->state.headerbuff,
+                                 headerlen);
+      if(result)
+        return result;
+
+      data->info.header_size += (long)headerlen;
+      data->req.headerbytecount += (long)headerlen;
+
+      data->req.deductheadercount =
+        (100 <= k->httpcode && 199 >= k->httpcode)?data->req.headerbytecount:0;
+
+      /* Curl_http_auth_act() checks what authentication methods
+       * that are available and decides which one (if any) to
+       * use. It will set 'newurl' if an auth method was picked. */
+      result = Curl_http_auth_act(conn);
+
+      if(result)
+        return result;
+
+      if(k->httpcode >= 300) {
+        if((!conn->bits.authneg) && !conn->bits.close &&
+           !conn->bits.rewindaftersend) {
+          /*
+           * General treatment of errors when about to send data. Including :
+           * "417 Expectation Failed", while waiting for 100-continue.
+           *
+           * The check for close above is done simply because of something
+           * else has already deemed the connection to get closed then
+           * something else should've considered the big picture and we
+           * avoid this check.
+           *
+           * rewindaftersend indicates that something has told libcurl to
+           * continue sending even if it gets discarded
+           */
+
+          switch(data->set.httpreq) {
+          case HTTPREQ_PUT:
+          case HTTPREQ_POST:
+          case HTTPREQ_POST_FORM:
+          case HTTPREQ_POST_MIME:
+            /* We got an error response. If this happened before the whole
+             * request body has been sent we stop sending and mark the
+             * connection for closure after we've read the entire response.
+             */
+            Curl_expire_done(data, EXPIRE_100_TIMEOUT);
+            if(!k->upload_done) {
+              if(data->set.http_keep_sending_on_error) {
+                infof(data, "HTTP error before end of send, keep sending\n");
+                if(k->exp100 > EXP100_SEND_DATA) {
+                  k->exp100 = EXP100_SEND_DATA;
+                  k->keepon |= KEEP_SEND;
+                }
+              }
+              else {
+                infof(data, "HTTP error before end of send, stop sending\n");
+                streamclose(conn, "Stop sending data before everything sent");
+                result = Curl_done_sending(conn, k);
+                if(result)
+                  return result;
+                k->upload_done = TRUE;
+                if(data->state.expect100header)
+                  k->exp100 = EXP100_FAILED;
+              }
+            }
+            break;
+
+          default: /* default label present to avoid compiler warnings */
+            break;
+          }
+        }
+
+        if(conn->bits.rewindaftersend) {
+          /* We rewind after a complete send, so thus we continue
+             sending now */
+          infof(data, "Keep sending data to get tossed away!\n");
+          k->keepon |= KEEP_SEND;
+        }
+      }
+
+      if(!k->header) {
+        /*
+         * really end-of-headers.
+         *
+         * If we requested a "no body", this is a good time to get
+         * out and return home.
+         */
+        if(data->set.opt_no_body)
+          *stop_reading = TRUE;
+#ifndef CURL_DISABLE_RTSP
+        else if((conn->handler->protocol & CURLPROTO_RTSP) &&
+                (data->set.rtspreq == RTSPREQ_DESCRIBE) &&
+                (k->size <= -1))
+          /* Respect section 4.4 of rfc2326: If the Content-Length header is
+             absent, a length 0 must be assumed.  It will prevent libcurl from
+             hanging on DESCRIBE request that got refused for whatever
+             reason */
+          *stop_reading = TRUE;
+#endif
+        else {
+          /* If we know the expected size of this document, we set the
+             maximum download size to the size of the expected
+             document or else, we won't know when to stop reading!
+
+             Note that we set the download maximum even if we read a
+             "Connection: close" header, to make sure that
+             "Content-Length: 0" still prevents us from attempting to
+             read the (missing) response-body.
+          */
+          /* According to RFC2616 section 4.4, we MUST ignore
+             Content-Length: headers if we are now receiving data
+             using chunked Transfer-Encoding.
+          */
+          if(k->chunk)
+            k->maxdownload = k->size = -1;
+        }
+        if(-1 != k->size) {
+          /* We do this operation even if no_body is true, since this
+             data might be retrieved later with curl_easy_getinfo()
+             and its CURLINFO_CONTENT_LENGTH_DOWNLOAD option. */
+
+          Curl_pgrsSetDownloadSize(data, k->size);
+          k->maxdownload = k->size;
+        }
+
+        /* If max download size is *zero* (nothing) we already have
+           nothing and can safely return ok now!  But for HTTP/2, we'd
+           like to call http2_handle_stream_close to properly close a
+           stream.  In order to do this, we keep reading until we
+           close the stream. */
+        if(0 == k->maxdownload
+#if defined(USE_NGHTTP2)
+           && !((conn->handler->protocol & PROTO_FAMILY_HTTP) &&
+                conn->httpversion == 20)
+#endif
+           )
+          *stop_reading = TRUE;
+
+        if(*stop_reading) {
+          /* we make sure that this socket isn't read more now */
+          k->keepon &= ~KEEP_RECV;
+        }
+
+        if(data->set.verbose)
+          Curl_debug(data, CURLINFO_HEADER_IN,
+                     k->str_start, headerlen);
+        break;          /* exit header line loop */
+      }
+
+      /* We continue reading headers, so reset the line-based
+         header parsing variables hbufp && hbuflen */
+      k->hbufp = data->state.headerbuff;
+      k->hbuflen = 0;
+      continue;
+    }
+
+    /*
+     * Checks for special headers coming up.
+     */
+
+    if(!k->headerline++) {
+      /* This is the first header, it MUST be the error code line
+         or else we consider this to be the body right away! */
+      int httpversion_major;
+      int rtspversion_major;
+      int nc = 0;
+#ifdef CURL_DOES_CONVERSIONS
+#define HEADER1 scratch
+#define SCRATCHSIZE 21
+      CURLcode res;
+      char scratch[SCRATCHSIZE + 1]; /* "HTTP/major.minor 123" */
+      /* We can't really convert this yet because we
+         don't know if it's the 1st header line or the body.
+         So we do a partial conversion into a scratch area,
+         leaving the data at k->p as-is.
+      */
+      strncpy(&scratch[0], k->p, SCRATCHSIZE);
+      scratch[SCRATCHSIZE] = 0; /* null terminate */
+      res = Curl_convert_from_network(data,
+                                      &scratch[0],
+                                      SCRATCHSIZE);
+      if(res)
+        /* Curl_convert_from_network calls failf if unsuccessful */
+        return res;
+#else
+#define HEADER1 k->p /* no conversion needed, just use k->p */
+#endif /* CURL_DOES_CONVERSIONS */
+
+      if(conn->handler->protocol & PROTO_FAMILY_HTTP) {
+        /*
+         * https://tools.ietf.org/html/rfc7230#section-3.1.2
+         *
+         * The response code is always a three-digit number in HTTP as the spec
+         * says. We try to allow any number here, but we cannot make
+         * guarantees on future behaviors since it isn't within the protocol.
+         */
+        char separator;
+        char twoorthree[2];
+        nc = sscanf(HEADER1,
+                    " HTTP/%1d.%1d%c%3d",
+                    &httpversion_major,
+                    &conn->httpversion,
+                    &separator,
+                    &k->httpcode);
+
+        if(nc == 1 && httpversion_major >= 2 &&
+           2 == sscanf(HEADER1, " HTTP/%1[23] %d", twoorthree, &k->httpcode)) {
+          conn->httpversion = 0;
+          nc = 4;
+          separator = ' ';
+        }
+
+        if((nc == 4) && (' ' == separator)) {
+          conn->httpversion += 10 * httpversion_major;
+
+          if(k->upgr101 == UPGR101_RECEIVED) {
+            /* supposedly upgraded to http2 now */
+            if(conn->httpversion != 20)
+              infof(data, "Lying server, not serving HTTP/2\n");
+          }
+          if(conn->httpversion < 20) {
+            conn->bundle->multiuse = BUNDLE_NO_MULTIUSE;
+            infof(data, "Mark bundle as not supporting multiuse\n");
+          }
+        }
+        else if(!nc) {
+          /* this is the real world, not a Nirvana
+             NCSA 1.5.x returns this crap when asked for HTTP/1.1
+          */
+          nc = sscanf(HEADER1, " HTTP %3d", &k->httpcode);
+          conn->httpversion = 10;
+
+          /* If user has set option HTTP200ALIASES,
+             compare header line against list of aliases
+          */
+          if(!nc) {
+            if(checkhttpprefix(data, k->p, k->hbuflen) == STATUS_DONE) {
+              nc = 1;
+              k->httpcode = 200;
+              conn->httpversion = 10;
+            }
+          }
+        }
+        else {
+          failf(data, "Unsupported HTTP version in response");
+          return CURLE_UNSUPPORTED_PROTOCOL;
+        }
+      }
+      else if(conn->handler->protocol & CURLPROTO_RTSP) {
+        char separator;
+        nc = sscanf(HEADER1,
+                    " RTSP/%1d.%1d%c%3d",
+                    &rtspversion_major,
+                    &conn->rtspversion,
+                    &separator,
+                    &k->httpcode);
+        if((nc == 4) && (' ' == separator)) {
+          conn->rtspversion += 10 * rtspversion_major;
+          conn->httpversion = 11; /* For us, RTSP acts like HTTP 1.1 */
+        }
+        else {
+          nc = 0;
+        }
+      }
+
+      if(nc) {
+        data->info.httpcode = k->httpcode;
+
+        data->info.httpversion = conn->httpversion;
+        if(!data->state.httpversion ||
+           data->state.httpversion > conn->httpversion)
+          /* store the lowest server version we encounter */
+          data->state.httpversion = conn->httpversion;
+
+        /*
+         * This code executes as part of processing the header.  As a
+         * result, it's not totally clear how to interpret the
+         * response code yet as that depends on what other headers may
+         * be present.  401 and 407 may be errors, but may be OK
+         * depending on how authentication is working.  Other codes
+         * are definitely errors, so give up here.
+         */
+        if(data->state.resume_from && data->set.httpreq == HTTPREQ_GET &&
+             k->httpcode == 416) {
+          /* "Requested Range Not Satisfiable", just proceed and
+             pretend this is no error */
+          k->ignorebody = TRUE; /* Avoid appending error msg to good data. */
+        }
+        else if(data->set.http_fail_on_error && (k->httpcode >= 400) &&
+           ((k->httpcode != 401) || !conn->bits.user_passwd) &&
+           ((k->httpcode != 407) || !conn->bits.proxy_user_passwd) ) {
+          /* serious error, go home! */
+          print_http_error(data);
+          return CURLE_HTTP_RETURNED_ERROR;
+        }
+
+        if(conn->httpversion == 10) {
+          /* Default action for HTTP/1.0 must be to close, unless
+             we get one of those fancy headers that tell us the
+             server keeps it open for us! */
+          infof(data, "HTTP 1.0, assume close after body\n");
+          connclose(conn, "HTTP/1.0 close after body");
+        }
+        else if(conn->httpversion == 20 ||
+                (k->upgr101 == UPGR101_REQUESTED && k->httpcode == 101)) {
+          DEBUGF(infof(data, "HTTP/2 found, allow multiplexing\n"));
+
+          /* HTTP/2 cannot blacklist multiplexing since it is a core
+             functionality of the protocol */
+          conn->bundle->multiuse = BUNDLE_MULTIPLEX;
+        }
+        else if(conn->httpversion >= 11 &&
+                !conn->bits.close) {
+          /* If HTTP version is >= 1.1 and connection is persistent */
+          DEBUGF(infof(data,
+                       "HTTP 1.1 or later with persistent connection\n"));
+        }
+
+        k->http_bodyless = k->httpcode >= 100 && k->httpcode < 200;
+        switch(k->httpcode) {
+        case 304:
+          /* (quote from RFC2616, section 10.3.5): The 304 response
+           * MUST NOT contain a message-body, and thus is always
+           * terminated by the first empty line after the header
+           * fields.  */
+          if(data->set.timecondition)
+            data->info.timecond = TRUE;
+          /* FALLTHROUGH */
+        case 204:
+          /* (quote from RFC2616, section 10.2.5): The server has
+           * fulfilled the request but does not need to return an
+           * entity-body ... The 204 response MUST NOT include a
+           * message-body, and thus is always terminated by the first
+           * empty line after the header fields. */
+          k->size = 0;
+          k->maxdownload = 0;
+          k->http_bodyless = TRUE;
+          break;
+        default:
+          break;
+        }
+      }
+      else {
+        k->header = FALSE;   /* this is not a header line */
+        break;
+      }
+    }
+
+    result = Curl_convert_from_network(data, k->p, strlen(k->p));
+    /* Curl_convert_from_network calls failf if unsuccessful */
+    if(result)
+      return result;
+
+    /* Check for Content-Length: header lines to get size */
+    if(!k->http_bodyless &&
+       !data->set.ignorecl && checkprefix("Content-Length:", k->p)) {
+      curl_off_t contentlength;
+      CURLofft offt = curlx_strtoofft(k->p + 15, NULL, 10, &contentlength);
+
+      if(offt == CURL_OFFT_OK) {
+        if(data->set.max_filesize &&
+           contentlength > data->set.max_filesize) {
+          failf(data, "Maximum file size exceeded");
+          return CURLE_FILESIZE_EXCEEDED;
+        }
+        k->size = contentlength;
+        k->maxdownload = k->size;
+        /* we set the progress download size already at this point
+           just to make it easier for apps/callbacks to extract this
+           info as soon as possible */
+        Curl_pgrsSetDownloadSize(data, k->size);
+      }
+      else if(offt == CURL_OFFT_FLOW) {
+        /* out of range */
+        if(data->set.max_filesize) {
+          failf(data, "Maximum file size exceeded");
+          return CURLE_FILESIZE_EXCEEDED;
+        }
+        streamclose(conn, "overflow content-length");
+        infof(data, "Overflow Content-Length: value!\n");
+      }
+      else {
+        /* negative or just rubbish - bad HTTP */
+        failf(data, "Invalid Content-Length: value");
+        return CURLE_WEIRD_SERVER_REPLY;
+      }
+    }
+    /* check for Content-Type: header lines to get the MIME-type */
+    else if(checkprefix("Content-Type:", k->p)) {
+      char *contenttype = Curl_copy_header_value(k->p);
+      if(!contenttype)
+        return CURLE_OUT_OF_MEMORY;
+      if(!*contenttype)
+        /* ignore empty data */
+        free(contenttype);
+      else {
+        Curl_safefree(data->info.contenttype);
+        data->info.contenttype = contenttype;
+      }
+    }
+    else if((conn->httpversion == 10) &&
+            conn->bits.httpproxy &&
+            Curl_compareheader(k->p,
+                               "Proxy-Connection:", "keep-alive")) {
+      /*
+       * When a HTTP/1.0 reply comes when using a proxy, the
+       * 'Proxy-Connection: keep-alive' line tells us the
+       * connection will be kept alive for our pleasure.
+       * Default action for 1.0 is to close.
+       */
+      connkeep(conn, "Proxy-Connection keep-alive"); /* don't close */
+      infof(data, "HTTP/1.0 proxy connection set to keep alive!\n");
+    }
+    else if((conn->httpversion == 11) &&
+            conn->bits.httpproxy &&
+            Curl_compareheader(k->p,
+                               "Proxy-Connection:", "close")) {
+      /*
+       * We get a HTTP/1.1 response from a proxy and it says it'll
+       * close down after this transfer.
+       */
+      connclose(conn, "Proxy-Connection: asked to close after done");
+      infof(data, "HTTP/1.1 proxy connection set close!\n");
+    }
+    else if((conn->httpversion == 10) &&
+            Curl_compareheader(k->p, "Connection:", "keep-alive")) {
+      /*
+       * A HTTP/1.0 reply with the 'Connection: keep-alive' line
+       * tells us the connection will be kept alive for our
+       * pleasure.  Default action for 1.0 is to close.
+       *
+       * [RFC2068, section 19.7.1] */
+      connkeep(conn, "Connection keep-alive");
+      infof(data, "HTTP/1.0 connection set to keep alive!\n");
+    }
+    else if(Curl_compareheader(k->p, "Connection:", "close")) {
+      /*
+       * [RFC 2616, section 8.1.2.1]
+       * "Connection: close" is HTTP/1.1 language and means that
+       * the connection will close when this request has been
+       * served.
+       */
+      streamclose(conn, "Connection: close used");
+    }
+    else if(!k->http_bodyless && checkprefix("Transfer-Encoding:", k->p)) {
+      /* One or more encodings. We check for chunked and/or a compression
+         algorithm. */
+      /*
+       * [RFC 2616, section 3.6.1] A 'chunked' transfer encoding
+       * means that the server will send a series of "chunks". Each
+       * chunk starts with line with info (including size of the
+       * coming block) (terminated with CRLF), then a block of data
+       * with the previously mentioned size. There can be any amount
+       * of chunks, and a chunk-data set to zero signals the
+       * end-of-chunks. */
+
+      result = Curl_build_unencoding_stack(conn, k->p + 18, TRUE);
+      if(result)
+        return result;
+    }
+    else if(!k->http_bodyless && checkprefix("Content-Encoding:", k->p) &&
+            data->set.str[STRING_ENCODING]) {
+      /*
+       * Process Content-Encoding. Look for the values: identity,
+       * gzip, deflate, compress, x-gzip and x-compress. x-gzip and
+       * x-compress are the same as gzip and compress. (Sec 3.5 RFC
+       * 2616). zlib cannot handle compress.  However, errors are
+       * handled further down when the response body is processed
+       */
+      result = Curl_build_unencoding_stack(conn, k->p + 17, FALSE);
+      if(result)
+        return result;
+    }
+    else if(checkprefix("Retry-After:", k->p)) {
+      /* Retry-After = HTTP-date / delay-seconds */
+      curl_off_t retry_after = 0; /* zero for unknown or "now" */
+      time_t date = curl_getdate(&k->p[12], NULL);
+      if(-1 == date) {
+        /* not a date, try it as a decimal number */
+        (void)curlx_strtoofft(&k->p[12], NULL, 10, &retry_after);
+      }
+      else
+        /* convert date to number of seconds into the future */
+        retry_after = date - time(NULL);
+      data->info.retry_after = retry_after; /* store it */
+    }
+    else if(!k->http_bodyless && checkprefix("Content-Range:", k->p)) {
+      /* Content-Range: bytes [num]-
+         Content-Range: bytes: [num]-
+         Content-Range: [num]-
+         Content-Range: [asterisk]/[total]
+
+         The second format was added since Sun's webserver
+         JavaWebServer/1.1.1 obviously sends the header this way!
+         The third added since some servers use that!
+         The forth means the requested range was unsatisfied.
+      */
+
+      char *ptr = k->p + 14;
+
+      /* Move forward until first digit or asterisk */
+      while(*ptr && !ISDIGIT(*ptr) && *ptr != '*')
+        ptr++;
+
+      /* if it truly stopped on a digit */
+      if(ISDIGIT(*ptr)) {
+        if(!curlx_strtoofft(ptr, NULL, 10, &k->offset)) {
+          if(data->state.resume_from == k->offset)
+            /* we asked for a resume and we got it */
+            k->content_range = TRUE;
+        }
+      }
+      else
+        data->state.resume_from = 0; /* get everything */
+    }
+#if !defined(CURL_DISABLE_COOKIES)
+    else if(data->cookies &&
+            checkprefix("Set-Cookie:", k->p)) {
+      Curl_share_lock(data, CURL_LOCK_DATA_COOKIE,
+                      CURL_LOCK_ACCESS_SINGLE);
+      Curl_cookie_add(data,
+                      data->cookies, TRUE, FALSE, k->p + 11,
+                      /* If there is a custom-set Host: name, use it
+                         here, or else use real peer host name. */
+                      conn->allocptr.cookiehost?
+                      conn->allocptr.cookiehost:conn->host.name,
+                      data->state.up.path,
+                      (conn->handler->protocol&CURLPROTO_HTTPS)?
+                      TRUE:FALSE);
+      Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
+    }
+#endif
+    else if(!k->http_bodyless && checkprefix("Last-Modified:", k->p) &&
+            (data->set.timecondition || data->set.get_filetime) ) {
+      time_t secs = time(NULL);
+      k->timeofdoc = curl_getdate(k->p + strlen("Last-Modified:"),
+                                  &secs);
+      if(data->set.get_filetime)
+        data->info.filetime = k->timeofdoc;
+    }
+    else if((checkprefix("WWW-Authenticate:", k->p) &&
+             (401 == k->httpcode)) ||
+            (checkprefix("Proxy-authenticate:", k->p) &&
+             (407 == k->httpcode))) {
+
+      bool proxy = (k->httpcode == 407) ? TRUE : FALSE;
+      char *auth = Curl_copy_header_value(k->p);
+      if(!auth)
+        return CURLE_OUT_OF_MEMORY;
+
+      result = Curl_http_input_auth(conn, proxy, auth);
+
+      free(auth);
+
+      if(result)
+        return result;
+    }
+  #ifdef USE_SPNEGO
+    else if(checkprefix("Persistent-Auth", k->p)) {
+      struct negotiatedata *negdata = &conn->negotiate;
+      struct auth *authp = &data->state.authhost;
+      if(authp->picked == CURLAUTH_NEGOTIATE) {
+        char *persistentauth = Curl_copy_header_value(k->p);
+        if(!persistentauth)
+          return CURLE_OUT_OF_MEMORY;
+        negdata->noauthpersist = checkprefix("false", persistentauth);
+        negdata->havenoauthpersist = TRUE;
+        infof(data, "Negotiate: noauthpersist -> %d, header part: %s",
+          negdata->noauthpersist, persistentauth);
+        free(persistentauth);
+      }
+    }
+  #endif
+    else if((k->httpcode >= 300 && k->httpcode < 400) &&
+            checkprefix("Location:", k->p) &&
+            !data->req.location) {
+      /* this is the URL that the server advises us to use instead */
+      char *location = Curl_copy_header_value(k->p);
+      if(!location)
+        return CURLE_OUT_OF_MEMORY;
+      if(!*location)
+        /* ignore empty data */
+        free(location);
+      else {
+        data->req.location = location;
+
+        if(data->set.http_follow_location) {
+          DEBUGASSERT(!data->req.newurl);
+          data->req.newurl = strdup(data->req.location); /* clone */
+          if(!data->req.newurl)
+            return CURLE_OUT_OF_MEMORY;
+
+          /* some cases of POST and PUT etc needs to rewind the data
+             stream at this point */
+          result = http_perhapsrewind(conn);
+          if(result)
+            return result;
+        }
+      }
+    }
+#ifdef USE_ALTSVC
+    /* If enabled, the header is incoming and this is over HTTPS */
+    else if(data->asi && checkprefix("Alt-Svc:", k->p) &&
+            ((conn->handler->flags & PROTOPT_SSL) ||
+#ifdef CURLDEBUG
+             /* allow debug builds to circumvent the HTTPS restriction */
+             getenv("CURL_ALTSVC_HTTP")
+#else
+             0
+#endif
+              )) {
+      /* the ALPN of the current request */
+      enum alpnid id = (conn->httpversion == 20) ? ALPN_h2 : ALPN_h1;
+      result = Curl_altsvc_parse(data, data->asi,
+                                 &k->p[ strlen("Alt-Svc:") ],
+                                 id, conn->host.name,
+                                 curlx_uitous(conn->remote_port));
+      if(result)
+        return result;
+    }
+#endif
+    else if(conn->handler->protocol & CURLPROTO_RTSP) {
+      result = Curl_rtsp_parseheader(conn, k->p);
+      if(result)
+        return result;
+    }
+
+    /*
+     * End of header-checks. Write them to the client.
+     */
+
+    writetype = CLIENTWRITE_HEADER;
+    if(data->set.include_header)
+      writetype |= CLIENTWRITE_BODY;
+
+    if(data->set.verbose)
+      Curl_debug(data, CURLINFO_HEADER_IN, k->p, (size_t)k->hbuflen);
+
+    result = Curl_client_write(conn, writetype, k->p, k->hbuflen);
+    if(result)
+      return result;
+
+    data->info.header_size += (long)k->hbuflen;
+    data->req.headerbytecount += (long)k->hbuflen;
+
+    /* reset hbufp pointer && hbuflen */
+    k->hbufp = data->state.headerbuff;
+    k->hbuflen = 0;
+  }
+  while(*k->str); /* header line within buffer */
+
+  /* We might have reached the end of the header part here, but
+     there might be a non-header part left in the end of the read
+     buffer. */
+
+  return CURLE_OK;
+}
+
+#endif /* CURL_DISABLE_HTTP */