From: Yann Ylavic <ylavic@apache.org>
Date: Fri, 3 Sep 2021 16:50:33 +0000 (+0000)
Subject: Merge r1892728 from trunk:
X-Git-Tag: candidate-2.4.49-rc1~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0ae75f345309a0d42cd906b5a69fefc47fbf5d7f;p=thirdparty%2Fapache%2Fhttpd.git

Merge r1892728 from trunk:

 * mod_deflate: refrain from reading buckets of known length, just
   to get their length. This may transform buckets unwanted (e.g. file
   to mmap) and prevent optimization down the filter chain.


Submitted by: icing
Reviewed by: icing, ylavic, jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1892873 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/modules/filters/mod_deflate.c b/modules/filters/mod_deflate.c
index b1cb15453fd..2431fd7e8c9 100644
--- a/modules/filters/mod_deflate.c
+++ b/modules/filters/mod_deflate.c
@@ -583,9 +583,14 @@ static apr_status_t deflate_out_filter(ap_filter_t *f,
                     continue;
                 }
 
-                rc = apr_bucket_read(e, &data, &blen, APR_BLOCK_READ);
-                if (rc != APR_SUCCESS)
-                    return rc;
+                if (e->length == (apr_size_t)-1) {
+                    rc = apr_bucket_read(e, &data, &blen, APR_BLOCK_READ);
+                    if (rc != APR_SUCCESS)
+                        return rc;
+                }
+                else {
+                    blen = e->length;
+                }
                 len += blen;
                 /* 50 is for Content-Encoding and Vary headers and ETag suffix */
                 if (len > sizeof(gzip_header) + VALIDATION_SIZE + 50)