transfer-encoding: added new option and cmdline

Added CURLOPT_TRANSFER_ENCODING as the option to set to request Transfer
Encoding in HTTP requests (if built zlib enabled). I also renamed
CURLOPT_ENCODING to CURLOPT_ACCEPT_ENCODING (while keeping the old name
around) to reduce the confusion when we have to encoding options for
HTTP.

--tr-encoding is now the new command line option for curl to request
this, and thus I updated the test cases accordingly.

3 files changed, 19 insertions, 7 deletions

diff --git a/lib/http.c b/lib/http.c
index 8d3a085d0..4f2b46a59 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -1733,21 +1733,28 @@ CURLcode Curl_http(struct connectdata *conn, bool *done)
       return CURLE_OUT_OF_MEMORY;
   }
 
-  if(Curl_checkheaders(data, "TE:")) {
-    /* When we 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 */
+#ifdef HAVE_LIBZ
+  /* we only consider transfer-encoding magic if libz support is built-in */
+
+  if(!Curl_checkheaders(data, "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(data, "Connection:");
+#define TE_HEADER "TE: gzip\r\n"
 
     Curl_safefree(conn->allocptr.te);
 
     /* Create the (updated) Connection: header */
-    conn->allocptr.te = cptr? aprintf("%s, TE\r\n", cptr):
-      strdup("Connection: TE\r\n");
+    conn->allocptr.te = cptr? aprintf("%s, TE\r\n" TE_HEADER, cptr):
+      strdup("Connection: TE\r\n" TE_HEADER);
 
     if(!conn->allocptr.te)
       return CURLE_OUT_OF_MEMORY;
   }
+#endif
 
   ptr = Curl_checkheaders(data, "Transfer-Encoding:");
   if(ptr) {
diff --git a/lib/url.c b/lib/url.c
index a31c28033..019f9a24b 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -1076,7 +1076,7 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
     data->set.http_auto_referer = (bool)(0 != va_arg(param, long));
     break;
 
-  case CURLOPT_ENCODING:
+  case CURLOPT_ACCEPT_ENCODING:
     /*
      * String to use at the value of Accept-Encoding header.
      *
@@ -1092,6 +1092,10 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
                        (char *) ALL_CONTENT_ENCODINGS: argptr);
     break;
 
+  case CURLOPT_TRANSFER_ENCODING:
+    data->set.http_transfer_encoding = (bool)(0 != va_arg(param, long));
+    break;
+
   case CURLOPT_FOLLOWLOCATION:
     /*
      * Follow Location: header hints on a HTTP-server.
diff --git a/lib/urldata.h b/lib/urldata.h
index 33933b3e1..96814cfb5 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1456,6 +1456,7 @@ struct UserDefined {
   bool hide_progress;    /* don't use the progress meter */
   bool http_fail_on_error;  /* fail on HTTP error codes >= 300 */
   bool http_follow_location; /* follow HTTP redirects */
+  bool http_transfer_encoding; /* request compressed HTTP transfer-encoding */
   bool http_disable_hostname_check_before_authentication;
   bool include_header;   /* include received protocol headers in data output */
   bool http_set_referer; /* is a custom referer used */