From c32f066785861dc966bce724220b818bf182b264 Mon Sep 17 00:00:00 2001
From: Jim Jagielski <jim@apache.org>
Date: Tue, 1 Nov 2016 11:53:57 +0000
Subject: [PATCH] Merge r1698239 from trunk: Submitted by: covener
 Reviewed/backported by: jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1767482 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES                     |  3 +++
 STATUS                      |  6 ------
 modules/http/http_request.c | 12 ++++++++++--
 server/request.c            | 13 +++++++++++--
 4 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/CHANGES b/CHANGES
index 3e8c26de2f..2eae5b3edd 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,6 +2,9 @@
 
 Changes with Apache 2.4.24
 
+  *) core: avoid adding multiple subrequest filters when there are nested
+     subrequests.  PR58292
+
   *) mod_http2: connection shutdown revisited: corrected edge cases on
      shutting down ongoing streams, changed log warnings to be less noisy
      when waiting on long running tasks. [Stefan Eissing]
diff --git a/STATUS b/STATUS
index d06d6df3ca..bfdda73857 100644
--- a/STATUS
+++ b/STATUS
@@ -117,12 +117,6 @@ RELEASE SHOWSTOPPERS:
 PATCHES ACCEPTED TO BACKPORT FROM TRUNK:
   [ start all new proposals below, under PATCHES PROPOSED. ]
 
-  *) core: avoid adding multiple subrequest filters when there are nested 
-     subrequests.  PR58292
-     trunk patch: http://svn.apache.org/r1698239
-     2.4.x patch: trunk works
-     +1: covener, ylavic, jim
-
   *) mod_remoteip: Pick up where we left off during a subrequest rather
      than running with the modified XFF but original TCP address. PR49839/PR60251
      trunk patch: http://svn.apache.org/r1688399  
diff --git a/modules/http/http_request.c b/modules/http/http_request.c
index 9ce7b8b329..b2dc893d41 100644
--- a/modules/http/http_request.c
+++ b/modules/http/http_request.c
@@ -711,8 +711,16 @@ AP_DECLARE(void) ap_internal_fast_redirect(request_rec *rr, request_rec *r)
     update_r_in_filters(r->output_filters, rr, r);
 
     if (r->main) {
-        ap_add_output_filter_handle(ap_subreq_core_filter_handle,
-                                    NULL, r, r->connection);
+        ap_filter_t *next = r->output_filters;
+        while (next && (next != r->proto_output_filters)) {
+            if (next->frec == ap_subreq_core_filter_handle) {
+                break;
+            }
+        }
+        if (!next || next == r->proto_output_filters) {
+            ap_add_output_filter_handle(ap_subreq_core_filter_handle,
+                                        NULL, r, r->connection);
+        }
     }
     else {
         /*
diff --git a/server/request.c b/server/request.c
index eecc0266b1..6eb14d591c 100644
--- a/server/request.c
+++ b/server/request.c
@@ -1960,6 +1960,8 @@ static request_rec *make_sub_request(const request_rec *r,
 
     /* start with the same set of output filters */
     if (next_filter) {
+        ap_filter_t *scan = next_filter;
+
         /* while there are no input filters for a subrequest, we will
          * try to insert some, so if we don't have valid data, the code
          * will seg fault.
@@ -1968,8 +1970,15 @@ static request_rec *make_sub_request(const request_rec *r,
         rnew->proto_input_filters = r->proto_input_filters;
         rnew->output_filters = next_filter;
         rnew->proto_output_filters = r->proto_output_filters;
-        ap_add_output_filter_handle(ap_subreq_core_filter_handle,
-                                    NULL, rnew, rnew->connection);
+        while (scan && (scan != r->proto_output_filters)) {
+            if (scan->frec == ap_subreq_core_filter_handle) {
+                break;
+            }
+        }
+        if (!scan || scan == r->proto_output_filters) {
+            ap_add_output_filter_handle(ap_subreq_core_filter_handle,
+                    NULL, rnew, rnew->connection);
+        }
     }
     else {
         /* If NULL - we are expecting to be internal_fast_redirect'ed
-- 
2.40.0