Fix detection of OpenFlow extensions submodule.

diff --git a/acinclude.m4 b/acinclude.m4
index 4dacae871a4101516a640a8f32a3767d186f7773..17283b1129735a6105694f072e5e749b9e8225fa 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -118,7 +118,7 @@ AC_DEFUN([OFP_ENABLE_EXT],
        HAVE_EXT=no
        ;;
      (*)
-       if test -d "$srcdir/ext"; then
+       if test -e "$srcdir/ext/configure"; then
          HAVE_EXT=yes
        else
          HAVE_EXT=no
@@ -126,7 +126,7 @@ AC_DEFUN([OFP_ENABLE_EXT],
        ;;
    esac
    if test $HAVE_EXT = yes; then
-     if test -d "$srcdir/ext"; then
+     if test -e "$srcdir/ext/configure"; then
        :
      else
        AC_MSG_ERROR([cannot configure extensions without "ext" directory])