nginx 0.6.17 *) Feature: the "If-Range" request header line support. Thanks to Alexander V. Inyukhin. *) Bugfix: URL double escaping in a redirect of the "msie_refresh" directive; bug appeared in 0.6.4. *) Bugfix: the "autoindex" directive did not work with the "alias /" directive. *) Bugfix: a segmentation fault might occur in worker process if subrequests were used. *) Bugfix: the big responses may be transferred truncated if SSL and gzip were used. *) Bugfix: the $status variable was equal to 0 if a proxied server returned response in HTTP/0.9 version.

--- a/src/http/modules/ngx_http_not_modified_filter_module.c
+++ b/src/http/modules/ngx_http_not_modified_filter_module.c
@@ -70,7 +70,7 @@ ngx_int_t ngx_http_not_modified_header_f
      * I think that the equality of the dates is correcter
      */
 
-    if (ims != NGX_ERROR && ims == r->headers_out.last_modified_time) {
+    if (ims == r->headers_out.last_modified_time) {
         r->headers_out.status = NGX_HTTP_NOT_MODIFIED;
         r->headers_out.content_type.len = 0;
         ngx_http_clear_content_length(r);