configure: Fix Graphviz test and input generation.

[sliver-openvswitch.git] / m4 / openvswitch.m4

diff --git a/m4/openvswitch.m4 b/m4/openvswitch.m4
index 5d77ca2..c5f0742 100644 (file)
--- a/m4/openvswitch.m4
+++ b/m4/openvswitch.m4
@@ -198,7 +198,7 @@ AC_DEFUN([OVS_CHECK_DOT],
     [for dot],
     [ovs_cv_dot],
     [dnl "dot" writes -V output to stderr:
-     if (dot -V) 2>&1 | grep '^dot - [gG]raphviz version' >/dev/null 2>&1; then
+     if (dot -V) 2>&1 | grep '^dot - [[gG]]raphviz version' >/dev/null 2>&1; then
        ovs_cv_dot=yes
      else
        ovs_cv_dot=no