handle the mmap() error of the file-size is 0 (fixes #1076)

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@1739 152afb58-edef-0310-8abb-c4023f1b3aa9

src/configfile.c

@@ -872,9 +872,14 @@ int config_parse_file(server *srv, config_t *context, const char *fn) {
 	}
 
 	if (0 != stream_open(&s, filename)) {
-		log_error_write(srv, __FILE__, __LINE__, "sbss",
-				"opening configfile ", filename, "failed:", strerror(errno));
-		ret = -1;
+		if (s.size == 0) {
+			/* the file was empty, nothing to parse */
+			ret = 0;
+		} else {
+			log_error_write(srv, __FILE__, __LINE__, "sbss",
+					"opening configfile ", filename, "failed:", strerror(errno));
+			ret = -1;
+		} 
 	} else {
 		tokenizer_init(&t, filename, s.start, s.size);
 		ret = config_parse(srv, context, &t);