[PATCH 11 of 20] Upstream: simplified Content-Encoding handling

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1650492330 -10800
#      Thu Apr 21 01:05:30 2022 +0300
# Node ID 6441069e16a0c4755c662bc07bdcb0960c9ac04a
# Parent  ee1a8a4aa2c262d25a4aa871cda4f6c4515fc85c
Upstream: simplified Content-Encoding handling.

Since introduction of offset handling in ngx_http_upstream_copy_header_line()
in revision 573:58475592100c, the ngx_http_upstream_copy_content_encoding()
function is no longer needed, as its behaviour is exactly equivalent to
ngx_http_upstream_copy_header_line() with appropriate offset.  As such,
the ngx_http_upstream_copy_content_encoding() function was removed.

Further, the u->headers_in.content_encoding field is not used anywhere,
so it was removed as well.

Further, Content-Encoding handling no longer depends on NGX_HTTP_GZIP,
as it can be used even without any gzip handling compiled in (for example,
in the charset filter).

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -147,11 +147,6 @@ static ngx_int_t ngx_http_upstream_rewri
 static ngx_int_t ngx_http_upstream_copy_allow_ranges(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 
-#if (NGX_HTTP_GZIP)
-static ngx_int_t ngx_http_upstream_copy_content_encoding(ngx_http_request_t *r,
-    ngx_table_elt_t *h, ngx_uint_t offset);
-#endif
-
 static ngx_int_t ngx_http_upstream_add_variables(ngx_conf_t *cf);
 static ngx_int_t ngx_http_upstream_addr_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
@@ -316,12 +311,10 @@ static ngx_http_upstream_header_t  ngx_h
                  ngx_http_upstream_process_transfer_encoding, 0,
                  ngx_http_upstream_ignore_header_line, 0, 0 },
 
-#if (NGX_HTTP_GZIP)
     { ngx_string("Content-Encoding"),
-                 ngx_http_upstream_process_header_line,
-                 offsetof(ngx_http_upstream_headers_in_t, content_encoding),
-                 ngx_http_upstream_copy_content_encoding, 0, 0 },
-#endif
+                 ngx_http_upstream_ignore_header_line, 0,
+                 ngx_http_upstream_copy_header_line,
+                 offsetof(ngx_http_headers_out_t, content_encoding), 0 },
 
     { ngx_null_string, NULL, 0, NULL, 0, 0 }
 };
@@ -5349,29 +5342,6 @@ ngx_http_upstream_copy_allow_ranges(ngx_
 }
 
 
-#if (NGX_HTTP_GZIP)
-
-static ngx_int_t
-ngx_http_upstream_copy_content_encoding(ngx_http_request_t *r,
-    ngx_table_elt_t *h, ngx_uint_t offset)
-{
-    ngx_table_elt_t  *ho;
-
-    ho = ngx_list_push(&r->headers_out.headers);
-    if (ho == NULL) {
-        return NGX_ERROR;
-    }
-
-    *ho = *h;
-
-    r->headers_out.content_encoding = ho;
-
-    return NGX_OK;
-}
-
-#endif
-
-
 static ngx_int_t
 ngx_http_upstream_add_variables(ngx_conf_t *cf)
 {
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -285,10 +285,6 @@ typedef struct {
     ngx_table_elt_t                 *transfer_encoding;
     ngx_table_elt_t                 *vary;
 
-#if (NGX_HTTP_GZIP)
-    ngx_table_elt_t                 *content_encoding;
-#endif
-
     ngx_table_elt_t                 *cache_control;
     ngx_table_elt_t                 *set_cookie;