[glib-networking] build: Retrieve D-Bus and systemd paths

[Iñigo Martínez <inigomartinez src gnome org>]

commit 101561dc4b28a4ab544c3a498003bc72eddaa63b
Author: Iñigo Martínez <inigomartinez gmail com>
Date:   Wed Nov 15 20:55:31 2017 +0100

    build: Retrieve D-Bus and systemd paths
    
    D-Bus' session bus services' path and systemd's user units path are
    hardcoded. However, these directories can be retrieved by checking
    this information from their pkgconfig files.
    
    This patch retrieves the path for their correspondant pkgconfig
    files and uses those paths as installation directories.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=790367

 meson.build                |    6 ++++++
 proxy/libproxy/meson.build |    4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index d807b6a..261195f 100644
--- a/meson.build
+++ b/meson.build
@@ -51,6 +51,12 @@ assert(gio_module_dir != '', 'GIO_MODULE_DIR is missing from gio-2.0.pc')
 # *** Checks for LibProxy   ***
 enable_libproxy_support = get_option('libproxy_support')
 if enable_libproxy_support
+  dbus_service_dir = dependency('dbus-1').get_pkgconfig_variable('session_bus_services_dir')
+  assert(dbus_service_dir != '', 'session_bus_services_dir is missing from dbus-1.pc')
+
+  systemd_user_unit_dir = dependency('systemd').get_pkgconfig_variable('systemduserunitdir')
+  assert(systemd_user_unit_dir != '', 'systemduserunitdir is missing from systemd.pc')
+
   libproxy_dep = dependency('libproxy-1.0', version: '>= 0.3.1', required: true)
 endif
 
diff --git a/proxy/libproxy/meson.build b/proxy/libproxy/meson.build
index 0db801a..bb88445 100644
--- a/proxy/libproxy/meson.build
+++ b/proxy/libproxy/meson.build
@@ -7,7 +7,7 @@ configure_file(
   input: service + '.in',
   output: service,
   install: true,
-  install_dir: join_paths(datadir, 'dbus-1', 'services'),
+  install_dir: dbus_service_dir,
   configuration: service_conf
 )
 
@@ -17,7 +17,7 @@ configure_file(
   input: service + '.in',
   output: service,
   install: true,
-  install_dir: join_paths(libdir, 'systemd', 'user'),
+  install_dir: systemd_user_unit_dir,
   configuration: service_conf
 )