env: preprend gst-build/prefix/etc/xdg to XDG_CONFIG_DIRS

So gst-build/prefix/etc/xdg/tizonia/tizonia.conf can be found.
Which one contains path to tizonia plugins. Useful when
compiling tizonia-openmax-il and installing it in gst-build
's prefix location:
  autoreconf -ifs
  ./configure --disable-player
              --without-libspotify
              --prefix=path_to_gst-build/prefix/
  make && make install

Allows the following to work:
  gst-launch-1.0 videotestsrc ! vp8enc ! omxvp8dec ! xvimagesink

diff --git a/gst-env.py b/gst-env.py
index 44faf7b..2f83fc1 100755 (executable)
--- a/gst-env.py
+++ b/gst-env.py
@@ -329,7 +329,7 @@ def get_subprocess_env(options, gst_version):
         prepend_env_var(env, 'PYTHONPATH', mesonpath, options.sysroot)
 
     # For devhelp books
-    if not 'XDG_DATA_DIRS' in env or not env['XDG_DATA_DIRS']:
+    if 'XDG_DATA_DIRS' not in env or not env['XDG_DATA_DIRS']:
         # Preserve default paths when empty
         prepend_env_var(env, 'XDG_DATA_DIRS', '/usr/local/share/:/usr/share/', '')
 
@@ -339,6 +339,13 @@ def get_subprocess_env(options, gst_version):
                                                         'GStreamer-doc'),
                      options.sysroot)
 
+    if 'XDG_CONFIG_DIRS' not in env or not env['XDG_CONFIG_DIRS']:
+        # Preserve default paths when empty
+        prepend_env_var(env, 'XDG_CONFIG_DIRS', '/etc/local/xdg:/etc/xdg', '')
+
+    prepend_env_var(env, "XDG_CONFIG_DIRS", os.path.join(PREFIX_DIR, 'etc', 'xdg'),
+                    options.sysroot)
+
     return env
 
 def get_windows_shell():