[PATCH] headers not sent when subrequests come from ap_die

[sterling <st...@covalent.net>]

Hi -

I have run across a situation where the header filters are not inserted
(when using ErrorDocument).  Back in the day we added the
add_required_filters call to ap_die to handle the scenario where the
request cycle didn't quite get to the insert_filters phase.  Problem is we
add those filters to the request.  However, the filter chain that is called is the one from the
last request (e.g. r->next) - Soooo, in the right scenario, the header
filters are not added to the right filter chain, hence no headers are
written back to the client.

here is a fix that works for me.  any comments?


sterling



Index: modules/http/http_request.c
===================================================================
RCS file: /home/cvspublic/httpd-2.0/modules/http/http_request.c,v
retrieving revision 1.117
diff -u -r1.117 http_request.c
--- modules/http/http_request.c	2001/10/30 19:21:41	1.117
+++ modules/http/http_request.c	2001/11/10 00:13:24
@@ -123,7 +123,8 @@
     int error_index = ap_index_of_response(type);
     char *custom_response = ap_response_code_string(r, error_index);
     int recursive_error = 0;
-
+    request_rec *cur;
+
     if (type == AP_FILTER_ERROR) {
         return;
     }
@@ -223,7 +224,14 @@
                         custom_response);
         }
     }
-    add_required_filters(r);
+
+    /* need to add the filters to the last request in the chain,
+       cuz thats the one that's called later on.
+    */
+    cur = r;
+    while( cur->next )
+        cur = cur->next;
+    add_required_filters(cur);
     ap_send_error_response(r, recursive_error);
 }

Re: [PATCH] headers not sent when subrequests come from ap_die

[sterling <st...@covalent.net>]

I realized I didn't give a specific reproducable case here (since I had
already found the problem):

try turning on Authentication for <Location /> - that way you will get a
401 while trying to serve up the 401 ErrorDocument
(ErrorDocument 401 /error/HTTP_UNAUTHORIZED.html.var).

You will see that you get a 401 error back, but no headers... which is
bad.

That is assuming you are using the default httpd.conf that has all the
ErrorDocument stuff in it and mod_include is enabled.

sterling

On Fri, 9 Nov 2001, sterling wrote:

> Hi -
>
> I have run across a situation where the header filters are not inserted
> (when using ErrorDocument).  Back in the day we added the
> add_required_filters call to ap_die to handle the scenario where the
> request cycle didn't quite get to the insert_filters phase.  Problem is we
> add those filters to the request.  However, the filter chain that is called is the one from the
> last request (e.g. r->next) - Soooo, in the right scenario, the header
> filters are not added to the right filter chain, hence no headers are
> written back to the client.
>
> here is a fix that works for me.  any comments?
>
>
> sterling
>
>
>
> Index: modules/http/http_request.c
> ===================================================================
> RCS file: /home/cvspublic/httpd-2.0/modules/http/http_request.c,v
> retrieving revision 1.117
> diff -u -r1.117 http_request.c
> --- modules/http/http_request.c	2001/10/30 19:21:41	1.117
> +++ modules/http/http_request.c	2001/11/10 00:13:24
> @@ -123,7 +123,8 @@
>      int error_index = ap_index_of_response(type);
>      char *custom_response = ap_response_code_string(r, error_index);
>      int recursive_error = 0;
> -
> +    request_rec *cur;
> +
>      if (type == AP_FILTER_ERROR) {
>          return;
>      }
> @@ -223,7 +224,14 @@
>                          custom_response);
>          }
>      }
> -    add_required_filters(r);
> +
> +    /* need to add the filters to the last request in the chain,
> +       cuz thats the one that's called later on.
> +    */
> +    cur = r;
> +    while( cur->next )
> +        cur = cur->next;
> +    add_required_filters(cur);
>      ap_send_error_response(r, recursive_error);
>  }
>
>
>