[dconf/wip/jtojnar/bash-completion-prefix] build: Install bash-completion relative to datadir

[Jan Tojnar <jtojnar src gnome org>]

commit 82e9a675fdf9937f90b65764f37025e76f79fd5b
Author: Jan Tojnar <jtojnar gmail com>
Date:   Thu Apr 16 11:21:06 2020 +0200

    build: Install bash-completion relative to datadir
    
    Now that bash-completion 2.10 has been released, we no longer need
    to rely on distro patches for overriding prefix but can pass datadir.
    
    Co-Authored-By: Iñigo Martínez <inigomartinez gmail com>

 meson.build | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index 6620112..9fecddb 100644
--- a/meson.build
+++ b/meson.build
@@ -50,8 +50,11 @@ dbus_session_service_dir = dependency('dbus-1').get_pkgconfig_variable('session_
 
 enable_bash_completion = get_option('bash_completion')
 if enable_bash_completion
-  # FIXME: the `.pc` file is wrong because `completionsdir` should be relative to `datadir`, not `prefix`
-  completions_dir = dependency('bash-completion').get_pkgconfig_variable('completionsdir', define_variable: 
['prefix', dconf_prefix])
+  bash_completion_dep = dependency('bash-completion')
+  completions_dir = bash_completion_dep.get_pkgconfig_variable(
+    'completionsdir',
+    define_variable: bash_completion_dep.version().version_compare('>= 2.10') ? ['datadir', dconf_datadir] : 
['prefix', dconf_prefix],
+  )
 endif
 
 configure_file(