[core] check whether server.chroot exists

From: Stefan Bühler <stbuehler@web.de>

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2896 152afb58-edef-0310-8abb-c4023f1b3aa9

NEWS

@@ -29,6 +29,7 @@ NEWS
   * [auth] put REMOTE_USER into cgi environment, making it accessible to lua via lighty.req_env (fixes #2495)
   * [auth] new method "extern" to use already present REMOTE_USER (from magnet, ssl, ...) (fixes #2436)
   * [core] remove requirement that default doc-root has to exist, there are reasonable scenarios not requiring static files at all
+  * [core] check whether server.chroot exists
 
 - 1.4.32 - 2012-11-21
   * Code cleanup with clang/sparse (fixes #2437, thx kibi)

src/configfile.c

@@ -1241,6 +1241,18 @@ int config_set_defaults(server *srv) {
 		{ FDEVENT_HANDLER_UNSET,          NULL }
 	};
 
+	if (!buffer_is_empty(srv->srvconf.changeroot)) {
+		if (-1 == stat(srv->srvconf.changeroot->ptr, &st1)) {
+			log_error_write(srv, __FILE__, __LINE__, "sb",
+					"server.chroot doesn't exist:", srv->srvconf.changeroot);
+			return -1;
+		}
+		if (!S_ISDIR(st1.st_mode)) {
+			log_error_write(srv, __FILE__, __LINE__, "sb",
+					"server.chroot isn't a directory:", srv->srvconf.changeroot);
+			return -1;
+		}
+	}
 
 	if (buffer_is_empty(s->document_root)) {
 		log_error_write(srv, __FILE__, __LINE__, "s",