gentoo-overlay/dev-lang/php/files/all_mysql_socket_location-gentoo.patch

diff -u a/ext/mysqlnd/mysqlnd.c b/ext/mysqlnd/mysqlnd.c
--- a/ext/mysqlnd/mysqlnd.c	2010-10-22 17:46:26.000000000 +0200
+++ b/ext/mysqlnd/mysqlnd.c	2010-12-08 21:54:47.000000000 +0100
@@ -619,7 +619,8 @@
 		if (host_len == sizeof("localhost") - 1 && !strncasecmp(host, "localhost", host_len)) {
 			DBG_INF_FMT("socket=%s", socket_or_pipe? socket_or_pipe:"n/a");
 			if (!socket_or_pipe) {
-				socket_or_pipe = "/tmp/mysql.sock";
+				// gentoo mysql default socket location
+				socket_or_pipe = "/var/run/mysqld/mysqld.sock";
 			}
 			transport_len = spprintf(&transport, 0, "unix://%s", socket_or_pipe);
 			unix_socket = TRUE;