[PATCH 1 of 5] Fix incorrect 201 replies from dav module

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1288669810 -10800
# Node ID 1e3045c3de6be5718359f4e0e3af9007f3da50aa
# Parent  94ea26a3b3aac367dc08ef9ef6c71f9ab8effa09
Fix incorrect 201 replies from dav module.

Replies with 201 code contain body, and we should clearly indicate it's
empty if it's empty.  Before 0.8.32 chunked was explicitly disabled for
201 replies and as a result empty body was indicated by connection close
(not perfect, but worked).  Since 0.8.32 chunked is enabled, and this
causes incorrect responses from dav module when HTTP/1.1 is used: with
"Transfer-Encoding: chunked" but no chunks at all.

Fix is to actually return empty body in special reponse handler instead
of abusing r->header_only flag.

See here for initial report:

http://nginx.org/pipermail/nginx-ru/2010-October/037535.html

diff --git a/src/http/ngx_http_special_response.c b/src/http/ngx_http_special_response.c
--- a/src/http/ngx_http_special_response.c
+++ b/src/http/ngx_http_special_response.c
@@ -410,7 +410,6 @@ ngx_http_special_response_handler(ngx_ht
     if (error == NGX_HTTP_CREATED) {
         /* 201 */
         err = 0;
-        r->header_only = 1;
 
     } else if (error == NGX_HTTP_NO_CONTENT) {
         /* 204 */
@@ -617,7 +616,7 @@ ngx_http_send_special_response(ngx_http_
         r->headers_out.content_type_lowcase = NULL;
 
     } else {
-        r->headers_out.content_length_n = -1;
+        r->headers_out.content_length_n = 0;
     }
 
     if (r->headers_out.content_length) {
@@ -635,7 +634,7 @@ ngx_http_send_special_response(ngx_http_
     }
 
     if (ngx_http_error_pages[err].len == 0) {
-        return NGX_OK;
+        return ngx_http_send_special(r, NGX_HTTP_LAST);
     }
 
     b = ngx_calloc_buf(r->pool);