Hi,
Attached is a patch that will solve the 304 turning into 200 response code
problem. It seems that in mod_disk_cache the status line was also saved
and restored from the cache. On a first request it is saved as "200 OK" or
something to the cache file. On subsequent requests it is restored into
r->status_line.
The problem occurs when afterwards mod_cache decides that the response
should be a "304 not modified". The status line is not reset in this case
and send as a "200 OK" response without a body.
The solution: not restoring the status line from the cache. The http
response header filter will then construct a status line starting from
the status code, which is 304. Problem solved.
Kris Verbeeck wrote:
>
> Hi,
>
> When refreshing a page (with IE) the browser sends a 'If-Modified-Since'
> header in the request. As seen in the debug log below, mod_cache has
> verified that the page has not been modified and wants to return an HTTP
> status 304. Somehow this 304 doesn't get to the browser. Instead of
> sending the 304 response apache sends a 200 response without a body
> (see ethereal output of request and response below). This results in the
> browser displaying an empty (white) page.
>
> If a request is send without the 'If-Modified-Since' header then everything
> works OK, i.e. a 200 response is send with the cached body.
>
> I have already been tracing through httpd with gdb, but found nothing.
> Does anyone have any idea about what is going on with the 304 response?
>
> Setup: apache httpd 2.0.40 (with cache patches from CVS)
>
> The request:
>
> GET /index.html HTTP/1.1
> Accept: */*
> Accept-Language: en-us
> Accept-Encoding: gzip, deflate
> If-Modified-Since: Thu, 02 May 2002 12:01:37 GMT; length=8809
> User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)
> Host: pino.be.ubizen.com
> Connection: Keep-Alive
>
> The response:
>
> HTTP/1.0 200
> Date: Tue, 10 Sep 2002 09:45:39 GMT
> Server: web server
> Connection: close
> etag: "b9829-2269-3cd12aa1"
>
> The debug log:
>
> [date] [debug] mod_cache.c(112): cache: URL /index.html is being handled by
>disk
> [date] [info] disk_cache: Serving Cached URL /index.html
> [date] [info] disk_cache: Served headers for URL /index.html
> [date] [debug] mod_cache.c(216): cache: fresh cache - returning status 304
>
> --
> ir. Kris Verbeeck
> Development Engineer
>
> Ubizen - Ubicenter - Philipssite 5 - 3001 Leuven - Belgium
> T: +32 16 28 70 64
> F: +32 16 28 70 77
>
> Ubizen - We Secure e-business - www.ubizen.com
--
ir. Kris Verbeeck
Development Engineer
Ubizen - Ubicenter - Philipssite 5 - 3001 Leuven - Belgium
T: +32 16 28 70 64
F: +32 16 28 70 77
Ubizen - We Secure e-business - www.ubizen.com
--- mod_disk_cache.c Wed Sep 11 16:33:25 2002
+++ mod_disk_cache.c-PATCHED Wed Sep 11 16:32:54 2002
@@ -484,6 +484,17 @@
r->status = atoi(urlbuff); /* Save status line into
request rec */
+ rv = apr_file_gets(&urlbuff[0], urllen, dobj->hfd); /* Read status
+line */
+ if (rv != APR_SUCCESS) {
+ /* XXX log message */
+ return rv;
+ }
+
+ if ((temp = strchr(&urlbuff[0], '\n')) != NULL) /* trim off new line
+character */
+ *temp = '\0'; /* overlay it with the null terminator */
+
+ r->status_line = apr_pstrdup(r->pool, urlbuff); /* Save status line
+into request rec */
+
h->req_hdrs = apr_table_make(r->pool, 20);
/*
