[nginx] Dav: fixed ngx_copy_file() to truncate destination file.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/3c357206a3b8
branches:  
changeset: 7328:3c357206a3b8
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Wed Aug 01 02:11:58 2018 +0300
description:
Dav: fixed ngx_copy_file() to truncate destination file.

Previously, ngx_open_file(NGX_FILE_CREATE_OR_OPEN) was used, resulting
in destination file being partially rewritten if exists.  Notably,
this affected WebDAV COPY command (ticket #1576).

diffstat:

 src/core/ngx_file.c |  3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diffs (13 lines):

diff --git a/src/core/ngx_file.c b/src/core/ngx_file.c
--- a/src/core/ngx_file.c
+++ b/src/core/ngx_file.c
@@ -839,8 +839,7 @@ ngx_copy_file(u_char *from, u_char *to, 
         goto failed;
     }
 
-    nfd = ngx_open_file(to, NGX_FILE_WRONLY, NGX_FILE_CREATE_OR_OPEN,
-                        cf->access);
+    nfd = ngx_open_file(to, NGX_FILE_WRONLY, NGX_FILE_TRUNCATE, cf->access);
 
     if (nfd == NGX_INVALID_FILE) {
         ngx_log_error(NGX_LOG_CRIT, cf->log, ngx_errno,