[libmicrohttpd] size MHD_SIZE_UNKNOWN should never be returned in header

[Brecht Sanders]

Hi,
I use libmicrohttpd on Windows (compiled under MSYS/MinGW).
I have been looking at why my dynamic pages (using 
MHD_create_response_from_callback) would not display on Internet 
Explorer (version 6) while they were fine on  Firefox.
Finally I found it: the header returned includes:
   Content-Length: 4294967295
This is 0xFFFFFFFF.
In the code I see:
   #define MHD_SIZE_UNKNOWN  ((uint64_t) -1LL)
which probably corresponds, assuming you use uint64_t for size 
everywhere and don't mix with size_t.
My first thought to fix this was to not return the length if it is 
MHD_SIZE_UNKNOWN.
However, on my platform the (MHD_SIZE_UNKNOWN != 
connection->response->total_size) comparison didn't seem to match.
I worked around it for now with the patch below using size_t typecasts.
However I suspect an underlying problem where size gets truncated from 
uint64_t to a smaller type (maybe size_t) somewhere else.
So my patch is not the perfect fix in case you will have file larger 
than 4G.
Regards
   Brecht Sanders


patch -ulb src/daemon/connection.c << EOF
--- src/daemon/connection.c  2010-03-11 13:34:20 +0100
+++ src/daemon/connection.c  2010-04-01 10:02:50 +0200
@@ -498,4 +498,5 @@
    }
-  else if (NULL == MHD_get_response_header (connection->response,
-                                            
MHD_HTTP_HEADER_CONTENT_LENGTH))
+  else if ((NULL == MHD_get_response_header (connection->response,
+                                            
MHD_HTTP_HEADER_CONTENT_LENGTH)) &&
+           ((size_t)MHD_SIZE_UNKNOWN != 
(size_t)connection->response->total_size))
    {
EOF