Sub-requests are created and used with two purposes; sometimes

simply to 'see' what a request would do; as to fill out an SSI,
validate access or similar - and is then discarded. And sometimes
as the precursor to becoming the actual request; e.g. when mod_dir
checks if an /index.html can be served for a '/'.

In the latter case it is important to preserve the output filters
'for real'; whereas in the first case they have to be reset to
purely the minimal proto filters (if at all). This patch instates
the output filters in 3 cases where sub-requests are/may in fact
be used as the real request later on.

This is a relatively risky change (which should not be back-ported 
without further discussion) and may break caches in combination 
with internal redirects/vary/negotiation in subtle ways.

See the thread starting at [1] and in particular the general 
concerns of rpluem at [2] with respect to sub requests 
and (fast_)internal redirects possibly needing a more 
thorough overhaul.

1: http://mail-archives.apache.org/mod_mbox/httpd-dev/200802.mbox/ajax/%3c335D1A4B-25E2-4FF1-8CDF-5010A7FBD293@webweaving.org%3e
2: http://mail-archives.apache.org/mod_mbox/httpd-dev/200802.mbox/%3c47ACE1D4.4060702@apache.org%3e



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@620133 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 5 insertions, 3 deletions

diff --git a/modules/mappers/mod_negotiation.c b/modules/mappers/mod_negotiation.c
index 3a89dc3f9c..c34fd8a952 100644
--- a/modules/mappers/mod_negotiation.c
+++ b/modules/mappers/mod_negotiation.c
@@ -1165,8 +1165,10 @@ static int read_types_multi(negotiation_state *neg)
 
         /* Double check, we still don't multi-resolve non-ordinary files
          */
-        if (sub_req->finfo.filetype != APR_REG)
+        if (sub_req->finfo.filetype != APR_REG) {
+	    /* XXX sub req not destroyed -- may be a bug/unintentional ? */
             continue;
+	}
 
         /* If it has a handler, we'll pretend it's a CGI script,
          * since that's a good indication of the sort of thing it
@@ -2712,7 +2714,7 @@ static int setup_choice_response(request_rec *r, negotiation_state *neg,
     if (!variant->sub_req) {
         int status;
 
-        sub_req = ap_sub_req_lookup_file(variant->file_name, r, NULL);
+        sub_req = ap_sub_req_lookup_file(variant->file_name, r, r->output_filters);
         status = sub_req->status;
 
         if (status != HTTP_OK &&
@@ -3122,7 +3124,7 @@ static int handle_multi(request_rec *r)
          * a sub_req structure yet.  Get one now.
          */
 
-        sub_req = ap_sub_req_lookup_file(best->file_name, r, NULL);
+        sub_req = ap_sub_req_lookup_file(best->file_name, r, r->output_filters);
         if (sub_req->status != HTTP_OK) {
             res = sub_req->status;
             ap_destroy_sub_req(sub_req);