adopt NGX_FILE_TRUNCATE for win32
diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 982ab12..c4d2b7f 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -63,7 +63,7 @@
#define NGX_FILE_RDWR O_RDWR
#define NGX_FILE_CREATE_OR_OPEN O_CREAT
#define NGX_FILE_OPEN 0
-#define NGX_FILE_TRUNCATE O_TRUNC
+#define NGX_FILE_TRUNCATE O_CREAT|O_TRUNC
#define NGX_FILE_APPEND O_WRONLY|O_APPEND
#define NGX_FILE_DEFAULT_ACCESS 0644
diff --git a/src/os/win32/ngx_files.h b/src/os/win32/ngx_files.h
index 5efd0fe..2efbc20 100644
--- a/src/os/win32/ngx_files.h
+++ b/src/os/win32/ngx_files.h
@@ -67,6 +67,7 @@
#define NGX_FILE_CREATE_OR_OPEN OPEN_ALWAYS
#define NGX_FILE_OPEN OPEN_EXISTING
+#define NGX_FILE_TRUNCATE CREATE_ALWAYS
#define NGX_FILE_DEFAULT_ACCESS 0
#define NGX_FILE_OWNER_ACCESS 0