When using mod_proxy as a reverse proxy, I hit the case where it would buffer
accross chunk boundaries for chunks that are returned to the client. The data
will no be sent until the buffer limit is reached. This breaks certain classes
of web applications that return intermediate results over http over an extended
period of time.

The fix is to apply the following diff to proxy_util.c. This forces each chunk
to be flushed to the socket when the end of the chunk is reached.

--- proxy_util.c.prev   2005-05-11 13:29:13.000000000 -0700
+++ proxy_util.c        2005-05-11 13:30:25.000000000 -0700
@@ -605,6 +605,10 @@
 
             w = ap_bwrite(con->client, &buf[o], n);
 
+            if (chunked) {
+              ap_bflush(con->client);
+            }
+
             if (alternate_timeouts)
                 ap_kill_timeout(r);
             else