[gnome-initial-setup] build: add an option to specify vendor configuration file

[Cosimo Cecchi <cosimoc src gnome org>]

commit c794f26d8b884a34d0660f31010fdc07bf7e0674
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Fri Mar 10 14:52:57 2017 -0800

    build: add an option to specify vendor configuration file
    
    This file will contain customization values for vendor extension
    points.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=783388

 configure.ac |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index fb0eab9..e76a581 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,6 +18,17 @@ AC_DEFINE_UNQUOTED(GETTEXT_PACKAGE, "$GETTEXT_PACKAGE", [gettext package])
 
 AM_GLIB_GNU_GETTEXT
 
+AC_ARG_WITH(vendor-conf-file,
+            AS_HELP_STRING([--with-vendor-conf-file=<file>],
+                           [vendor conf file]))
+
+if ! test -z "$with_vendor_conf_file"; then
+   VENDOR_CONF_FILE=$with_vendor_conf_file
+else
+   VENDOR_CONF_FILE=${localstatedir}/lib/gnome-initial-setup/vendor.conf
+fi
+AC_SUBST(VENDOR_CONF_FILE)
+
 LIBNM_REQUIRED_VERSION=1.2
 LIBNMA_REQUIRED_VERSION=1.0
 GLIB_REQUIRED_VERSION=2.53.0