[PATCH] Gzip static: ranges support (ticket #2349)

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1672713976 -10800
#      Tue Jan 03 05:46:16 2023 +0300
# Node ID e0688b4494f02dcf6feebf0c73e02749bd7de381
# Parent  07b0bee87f32be91a33210bc06973e07c4c1dac9
Gzip static: ranges support (ticket #2349).

In contrast to on-the-fly gzipping with gzip filter, static gzipped
representation as returned by gzip_static is persistent, and therefore
the same binary representation is available for future requests, making
it possible to use range requests.

Further, if a gzipped representation is re-generated with different
compression settings, it is expected to result in different ETag and
different size reported in the Content-Range header, making it possible
to safely use range requests anyway.

As such, ranges are now allowed for files returned by gzip_static.

diff --git a/src/http/modules/ngx_http_gzip_static_module.c b/src/http/modules/ngx_http_gzip_static_module.c
--- a/src/http/modules/ngx_http_gzip_static_module.c
+++ b/src/http/modules/ngx_http_gzip_static_module.c
@@ -247,6 +247,8 @@ ngx_http_gzip_static_handler(ngx_http_re
     ngx_str_set(&h->value, "gzip");
     r->headers_out.content_encoding = h;
 
+    r->allow_ranges = 1;
+
     /* we need to allocate all before the header would be sent */
 
     b = ngx_calloc_buf(r->pool);