[gnome-session] meson: unconditionally copy session file

[Ray Strode <halfline src gnome org>]

commit 9b37ffc6b82580f5213c2ea7e96b398ff45fa722
Author: Ray Strode <rstrode redhat com>
Date:   Mon Jan 8 16:39:19 2018 -0500

    meson: unconditionally copy session file
    
    gnome.desktop is installed in two places, but only if
    DESTDIR is unset..
    
    This commit makes it always happen.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=792207

 meson_post_install.py |   23 ++++++++++++++---------
 1 files changed, 14 insertions(+), 9 deletions(-)
---
diff --git a/meson_post_install.py b/meson_post_install.py
index 54361bf..e2e352c 100644
--- a/meson_post_install.py
+++ b/meson_post_install.py
@@ -5,17 +5,22 @@ import shutil
 import subprocess
 import sys
 
+if os.environ.get('DESTDIR'):
+  install_root = os.environ.get('DESTDIR') + os.path.abspath(sys.argv[1])
+else:
+  install_root = sys.argv[1]
+
 if not os.environ.get('DESTDIR'):
-  schemadir = os.path.join(sys.argv[1], 'glib-2.0', 'schemas')
+  schemadir = os.path.join(install_root, 'glib-2.0', 'schemas')
   print('Compile gsettings schemas...')
   subprocess.call(['glib-compile-schemas', schemadir])
 
-  # FIXME: this is due to unable to copy a generated target file:
-  #        https://groups.google.com/forum/#!topic/mesonbuild/3iIoYPrN4P0
-  dst_dir = os.path.join(sys.argv[1], 'wayland-sessions')
-  if not os.path.exists(dst_dir):
-    os.makedirs(dst_dir)
+# FIXME: this is due to unable to copy a generated target file:
+#        https://groups.google.com/forum/#!topic/mesonbuild/3iIoYPrN4P0
+dst_dir = os.path.join(install_root, 'wayland-sessions')
+if not os.path.exists(dst_dir):
+  os.makedirs(dst_dir)
 
-  src = os.path.join(sys.argv[1], 'xsessions', 'gnome.desktop')
-  dst = os.path.join(dst_dir, 'gnome.desktop')
-  shutil.copyfile(src, dst)
+src = os.path.join(install_root, 'xsessions', 'gnome.desktop')
+dst = os.path.join(dst_dir, 'gnome.desktop')
+shutil.copyfile(src, dst)