nginx 0.8.36 *) Bugfix: the ngx_http_dav_module handled incorrectly the DELETE, COPY, and MOVE methods for symlinks. *) Bugfix: values of the $query_string, $arg_..., etc. variables cached in main request were used by the SSI module in subrequests. *) Bugfix: a variable value was repeatedly encoded after each an "echo" SSI-command output; the bug had appeared in 0.6.14. *) Bugfix: a worker process hung if a FIFO file was requested. Thanks to Vicente Aguilar and Maxim Dounin. *) Bugfix: OpenSSL-1.0.0 compatibility on 64-bit Linux. Thanks to Maxim Dounin. *) Bugfix: nginx could not be built --without-http-cache; the bug had appeared in 0.8.35.

--- a/src/core/ngx_open_file_cache.c
+++ b/src/core/ngx_open_file_cache.c
@@ -490,7 +490,14 @@ ngx_open_and_stat_file(u_char *name, ngx
     }
 
     if (!of->log) {
-        fd = ngx_open_file(name, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);
+
+        /*
+         * Use non-blocking open() not to hang on FIFO files, etc.
+         * This flag has no effect on a regular files.
+         */
+
+        fd = ngx_open_file(name, NGX_FILE_RDONLY|NGX_FILE_NONBLOCK,
+                           NGX_FILE_OPEN, 0);
 
     } else {
         fd = ngx_open_file(name, NGX_FILE_APPEND, NGX_FILE_CREATE_OR_OPEN,