[PATCH libnetfilter_queue] build: check whether dot is available when configuring doxygen.

[Jeremy Sowden <jeremy@azazel.net>]

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---
 configure.ac   | 4 ++++
 doxygen.cfg.in | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index d8d1d387c773..32e499071b26 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,6 +41,10 @@ AC_ARG_WITH([doxygen], [AS_HELP_STRING([--with-doxygen],
 	    [], [with_doxygen=no])
 AS_IF([test "x$with_doxygen" = xyes], [
 	AC_CHECK_PROGS([DOXYGEN], [doxygen])
+	AC_CHECK_PROGS([DOT], [dot], [""])
+	AS_IF([test "x$DOT" != "x"],
+	      [AC_SUBST(HAVE_DOT, YES)],
+	      [AC_SUBST(HAVE_DOT, NO)])
 ])
 
 AM_CONDITIONAL([HAVE_DOXYGEN], [test -n "$DOXYGEN"])
diff --git a/doxygen.cfg.in b/doxygen.cfg.in
index 3f13f97ad8ba..c54f534ada3f 100644
--- a/doxygen.cfg.in
+++ b/doxygen.cfg.in
@@ -161,7 +161,7 @@ PERL_PATH              = /usr/bin/perl
 CLASS_DIAGRAMS         = YES
 MSCGEN_PATH            =
 HIDE_UNDOC_RELATIONS   = YES
-HAVE_DOT               = YES
+HAVE_DOT               = @HAVE_DOT@
 CLASS_GRAPH            = YES
 COLLABORATION_GRAPH    = YES
 GROUP_GRAPHS           = YES
-- 
2.28.0