copy from src/http/ngx_http_output_filter.c
copy to src/http/ngx_http_copy_filter.c
--- a/src/http/ngx_http_output_filter.c
+++ b/src/http/ngx_http_copy_filter.c
@@ -6,28 +6,29 @@
 
 typedef struct {
     ngx_bufs_t  bufs;
-} ngx_http_output_filter_conf_t;
+} ngx_http_copy_filter_conf_t;
 
 
-static void *ngx_http_output_filter_create_conf(ngx_conf_t *cf);
-static char *ngx_http_output_filter_merge_conf(ngx_conf_t *cf,
-                                               void *parent, void *child);
+static void *ngx_http_copy_filter_create_conf(ngx_conf_t *cf);
+static char *ngx_http_copy_filter_merge_conf(ngx_conf_t *cf,
+                                             void *parent, void *child);
+static ngx_int_t ngx_http_copy_filter_init(ngx_cycle_t *cycle);
 
 
-static ngx_command_t  ngx_http_output_filter_commands[] = {
+static ngx_command_t  ngx_http_copy_filter_commands[] = {
 
     {ngx_string("output_buffers"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
      ngx_conf_set_bufs_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
-     offsetof(ngx_http_output_filter_conf_t, bufs),
+     offsetof(ngx_http_copy_filter_conf_t, bufs),
      NULL},
 
     ngx_null_command
 };
 
 
-static ngx_http_module_t  ngx_http_output_filter_module_ctx = {
+static ngx_http_module_t  ngx_http_copy_filter_module_ctx = {
     NULL,                                  /* pre conf */
 
     NULL,                                  /* create main configuration */
@@ -36,40 +37,41 @@ static ngx_http_module_t  ngx_http_outpu
     NULL,                                  /* create server configuration */
     NULL,                                  /* merge server configuration */
 
-    ngx_http_output_filter_create_conf,    /* create location configuration */
-    ngx_http_output_filter_merge_conf      /* merge location configuration */
+    ngx_http_copy_filter_create_conf,      /* create location configuration */
+    ngx_http_copy_filter_merge_conf        /* merge location configuration */
 };
 
 
-ngx_module_t  ngx_http_output_filter_module = {
+ngx_module_t  ngx_http_copy_filter_module = {
     NGX_MODULE,
-    &ngx_http_output_filter_module_ctx,    /* module context */
-    ngx_http_output_filter_commands,       /* module directives */
+    &ngx_http_copy_filter_module_ctx,      /* module context */
+    ngx_http_copy_filter_commands,         /* module directives */
     NGX_HTTP_MODULE,                       /* module type */
-    NULL,                                  /* init module */
-    NULL                                   /* init child */
+    ngx_http_copy_filter_init,             /* init module */
+    NULL                                   /* init process */
 };
 
 
+static ngx_http_output_body_filter_pt    ngx_http_next_filter;
 
-ngx_int_t ngx_http_output_filter(ngx_http_request_t *r, ngx_chain_t *in)
+
+ngx_int_t ngx_http_copy_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
-    ngx_int_t                       rc;
-    ngx_output_chain_ctx_t         *ctx;
-    ngx_http_output_filter_conf_t  *conf;
+    ngx_output_chain_ctx_t       *ctx;
+    ngx_http_copy_filter_conf_t  *conf;
 
     if (r->connection->write->error) {
         return NGX_ERROR;
     }
 
     ctx = ngx_http_get_module_ctx(r->main ? r->main : r,
-                                            ngx_http_output_filter_module);
+                                            ngx_http_copy_filter_module);
 
     if (ctx == NULL) {
         conf = ngx_http_get_module_loc_conf(r->main ? r->main : r,
-                                            ngx_http_output_filter_module);
+                                            ngx_http_copy_filter_module);
 
-        ngx_http_create_ctx(r, ctx, ngx_http_output_filter_module,
+        ngx_http_create_ctx(r, ctx, ngx_http_copy_filter_module,
                             sizeof(ngx_output_chain_ctx_t), NGX_ERROR);
 
         ctx->sendfile = r->sendfile;
@@ -78,33 +80,23 @@ ngx_int_t ngx_http_output_filter(ngx_htt
 
         ctx->pool = r->pool;
         ctx->bufs = conf->bufs;
-        ctx->tag = (ngx_hunk_tag_t) &ngx_http_output_filter_module;
+        ctx->tag = (ngx_hunk_tag_t) &ngx_http_copy_filter_module;
 
-        ctx->output_filter = (ngx_output_chain_filter_pt)
-                                                      ngx_http_top_body_filter;
+        ctx->output_filter = (ngx_output_chain_filter_pt) ngx_http_next_filter;
         ctx->filter_ctx = r;
 
     }
 
-    rc = ngx_output_chain(ctx, in);
-
-    if (rc == NGX_ERROR) {
-
-        /* NGX_ERROR could be returned by any filter */
-
-        r->connection->write->error = 1;
-    }
-
-    return rc;
+    return  ngx_output_chain(ctx, in);
 }
 
 
-static void *ngx_http_output_filter_create_conf(ngx_conf_t *cf)
+static void *ngx_http_copy_filter_create_conf(ngx_conf_t *cf)
 {
-    ngx_http_output_filter_conf_t *conf;
+    ngx_http_copy_filter_conf_t *conf;
 
     ngx_test_null(conf,
-                  ngx_palloc(cf->pool, sizeof(ngx_http_output_filter_conf_t)),
+                  ngx_palloc(cf->pool, sizeof(ngx_http_copy_filter_conf_t)),
                   NULL);
 
     conf->bufs.num = 0;
@@ -113,13 +105,23 @@ static void *ngx_http_output_filter_crea
 }
 
 
-static char *ngx_http_output_filter_merge_conf(ngx_conf_t *cf,
-                                               void *parent, void *child)
+static char *ngx_http_copy_filter_merge_conf(ngx_conf_t *cf,
+                                             void *parent, void *child)
 {
-    ngx_http_output_filter_conf_t *prev = parent;
-    ngx_http_output_filter_conf_t *conf = child;
+    ngx_http_copy_filter_conf_t *prev = parent;
+    ngx_http_copy_filter_conf_t *conf = child;
 
     ngx_conf_merge_bufs_value(conf->bufs, prev->bufs, 1, 32768);
 
     return NULL;
 }
+
+
+static ngx_int_t ngx_http_copy_filter_init(ngx_cycle_t *cycle)
+{
+    ngx_http_next_filter = ngx_http_top_body_filter;
+    ngx_http_top_body_filter = ngx_http_copy_filter;
+
+    return NGX_OK;
+}
+