[libmicrohttpd] POST with chunked encoding fails

[Eivind Sarto]

I was was having problems receiving data from a client using POST with chunked 
encoding.
It turns out this client is violating the HTTP spec by setting the 
"Transfer-Encoding: Chunked"
as well as "Content-Length: 0"

Here are the client headers:
  POST /ee4/live.isml/Streams(Encoder1) HTTP/1.1
  Transfer-Encoding: Chunked
  User-Agent: ExpressionEncoder
  Host: 10.11.1.29
  Content-Length: 0
  Connection: Keep-Alive
  Cache-Control: no-cache

This is what HTTP 1.1 spec says (in section 4.4):
  Messages MUST NOT include both a Content-Length header field and a 
non-identity transfer-coding. If the message does include
  a non- identity transfer-coding, the Content-Length MUST be ignored.

libmicrohttpd does the opposite of what the 4.4 section says if both headers 
are present.  It only uses the content-length and ignores the
chunked encoding.
I patched libmicrohttpd with the attached patch that does the opposite.  It 
ignores the content-length if chunked encoding is also specified.
And with that patch libmicrohttpd can be a publishing point for MS Expression 
Encoder.

What is your take on this?

-eivind
--- src/daemon/connection.c	2012-12-17 16:38:44.000000000 -0800
+++ src/daemon/connection.c	2012-12-18 11:07:46.566692788 -0800
@@ -1769,40 +1769,36 @@ parse_connection_headers (struct MHD_Con
       return;
     }
 
-  clen = MHD_lookup_connection_value (connection,
-                                      MHD_HEADER_KIND,
-                                      MHD_HTTP_HEADER_CONTENT_LENGTH);
-  if (clen != NULL)
+  connection->remaining_upload_size = 0;
+  enc = MHD_lookup_connection_value (connection,
+				     MHD_HEADER_KIND,
+				     MHD_HTTP_HEADER_TRANSFER_ENCODING);
+  if (enc != NULL)
     {
-      cval = strtoul (clen, &end, 10);
-      if ( ('\0' != *end) ||
-	 ( (LONG_MAX == cval) && (errno == ERANGE) ) )
+      connection->remaining_upload_size = MHD_SIZE_UNKNOWN;
+      if (0 == strcasecmp (enc, "chunked"))
+        connection->have_chunked_upload = MHD_YES;
+    }
+  else
+    {
+      clen = MHD_lookup_connection_value (connection,
+					  MHD_HEADER_KIND,
+					  MHD_HTTP_HEADER_CONTENT_LENGTH);
+      if (clen != NULL)
         {
+          cval = strtoul (clen, &end, 10);
+          if ( ('\0' != *end) ||
+	     ( (LONG_MAX == cval) && (errno == ERANGE) ) )
+            {
 #if HAVE_MESSAGES
-          MHD_DLOG (connection->daemon,
+              MHD_DLOG (connection->daemon,
                     "Failed to parse `%s' header `%s', closing connection.\n",
                     MHD_HTTP_HEADER_CONTENT_LENGTH, clen);
 #endif
-	  CONNECTION_CLOSE_ERROR (connection, NULL);
-          return;
-        }
-      connection->remaining_upload_size = cval;
-    }
-  else
-    {
-      enc = MHD_lookup_connection_value (connection,
-					 MHD_HEADER_KIND,
-					 MHD_HTTP_HEADER_TRANSFER_ENCODING);
-      if (NULL == enc)
-        {
-          /* this request (better) not have a body */
-          connection->remaining_upload_size = 0;
-        }
-      else
-        {
-          connection->remaining_upload_size = MHD_SIZE_UNKNOWN;
-          if (0 == strcasecmp (enc, "chunked"))
-	    connection->have_chunked_upload = MHD_YES;
+	      CONNECTION_CLOSE_ERROR (connection, NULL);
+              return;
+            }
+          connection->remaining_upload_size = cval;
         }
     }
 }