[mutter] meson: Add udev_dir option

[Marge Bot <marge-bot src gnome org>]

commit c5943cd082461563fbfc89619a2e118b6e04f957
Author: Michel Dänzer <mdaenzer redhat com>
Date:   Thu Apr 29 16:33:36 2021 +0200

    meson: Add udev_dir option
    
    Same as in gnome-settings-daemon, allows overriding where to install
    udev rules files.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1844>

 data/meson.build  | 2 +-
 meson.build       | 6 +++++-
 meson_options.txt | 6 ++++++
 3 files changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/data/meson.build b/data/meson.build
index bf5c409d70..b1e81d1b5c 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -61,6 +61,6 @@ install_data(['mutter-schemas.convert'],
 
 if have_libgudev
   install_data(['61-mutter.rules'],
-    install_dir: join_paths(udevdir, 'rules.d'),
+    install_dir: join_paths(udev_dir, 'rules.d'),
   )
 endif
diff --git a/meson.build b/meson.build
index 6ba3ab45e6..28b7645c73 100644
--- a/meson.build
+++ b/meson.build
@@ -181,7 +181,11 @@ if have_libgudev
   libudev_dep = dependency('libudev', version: udev_req)
   gudev_dep = dependency('gudev-1.0', version: gudev_req)
   udev_dep = dependency('udev')
-  udevdir = udev_dep.get_pkgconfig_variable('udevdir')
+
+  udev_dir = get_option('udev_dir')
+  if udev_dir == ''
+    udev_dir = udev_dep.get_pkgconfig_variable('udevdir')
+  endif
 endif
 
 have_native_backend = get_option('native_backend')
diff --git a/meson_options.txt b/meson_options.txt
index 84e7dcc6c9..61d9cb48d1 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -69,6 +69,12 @@ option('udev',
   description: 'Enable udev support when using the X11 backend'
 )
 
+option('udev_dir',
+  type: 'string',
+  value: '',
+  description: 'Absolute path of the udev base directory'
+)
+
 option('libwacom',
   type: 'boolean',
   value: true,