# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1498514026 -10800
# Node ID aeaac3ccee4f6fb4ab7928126028a55d107ee147
# Parent  bd2f97a3aecc14f8a971fd8fd710979736131c23
Range filter: allowed ranges on empty files (ticket #1031).

As per RFC 2616 / RFC 7233, any range request to an empty file
is expected to result in 416 Range Not Satisfiable response, as
there cannot be a "byte-range-spec whose first-byte-pos is less
than the current length of the entity-body".  On the other hand,
this makes use of byte-range requests inconvenient in some cases,
as reported for the slice module here:

http://mailman.nginx.org/pipermail/nginx-devel/2017-June/010177.html

This commit changes range filter to instead return 200 if the file
is empty and the range requested starts at 0.

diff --git a/src/http/modules/ngx_http_range_filter_module.c b/src/http/modules/ngx_http_range_filter_module.c
--- a/src/http/modules/ngx_http_range_filter_module.c
+++ b/src/http/modules/ngx_http_range_filter_module.c
@@ -382,6 +382,9 @@ ngx_http_range_parse(ngx_http_request_t 
             if (ranges-- == 0) {
                 return NGX_DECLINED;
             }
+
+        } else if (start == 0) {
+            return NGX_DECLINED;
         }
 
         if (*p++ != ',') {