build: Make D-Bus policy configuration install optional

Makefile.am

@@ -8,8 +8,10 @@ builtin_sources =
 
 noinst_LTLIBRARIES = ell/libell-internal.la
 
+if DBUSCONF
 dbusdir = @DBUS_CONFDIR@/dbus-1/system.d
 dist_dbus_DATA = src/iwd-dbus.conf
+endif
 
 ell_sources = ell/ell.h ell/private.h ell/missing.h \
 			ell/util.h ell/util.c \
@@ -269,10 +271,12 @@ EXTRA_DIST = src/genbuiltin doc/main.conf $(manual_pages:.1=.txt)
 
 AM_CFLAGS = -fvisibility=hidden
 
-MAINTAINERCLEANFILES = Makefile.in configure config.h.in aclocal.m4
+DISTCHECK_CONFIGURE_FLAGS = --disable-dbusconf
 
 DISTCLEANFILES = $(BUILT_SOURCES) $(unit_tests) $(manual_pages)
 
+MAINTAINERCLEANFILES = Makefile.in configure config.h.in aclocal.m4
+
 BUILT_SOURCES = ell/internal src/builtin.h
 
 ell/internal: Makefile

bootstrap-configure

@@ -9,4 +9,4 @@ fi
 		--enable-debug \
 		--prefix=/usr \
 		--localstatedir=/var \
-		--with-dbusconfdir=/etc $*
+		--disable-dbusconf $*

configure.ac

@@ -89,10 +89,15 @@ AC_CHECK_HEADERS(linux/types.h linux/if_alg.h)
 AC_CHECK_HEADERS(readline/readline.h, enable_readline=yes,
 			AC_MSG_ERROR(readline header files are required))
 
+AC_ARG_ENABLE([dbusconf], AC_HELP_STRING([--disable-dbusconf],
+				[don't install D-Bus system policy file]),
+					[enable_dbusconf=${enableval}])
+AM_CONDITIONAL(DBUSCONF, test "${enable_dbusconf}" != "no")
+
 AC_ARG_WITH([dbusconfdir], AC_HELP_STRING([--with-dbusconfdir=DIR],
 				[path to D-Bus configuration directory]),
 					[path_dbusconfdir=${withval}])
-if (test -z "${path_dbusconfdir}"); then
+if (test "${enable_dbusconf}" != "no" && test -z "${path_dbusconfdir}"); then
 	AC_MSG_CHECKING([D-Bus configuration directory])
 	path_dbusconfdir="`$PKG_CONFIG --variable=sysconfdir dbus-1`"
 	if (test -z "${path_dbusconfdir}"); then