[dconf-editor/wip/jtojnar/schema-dir-multi] Support multiple directories in GSETTINGS_SCHEMA_DIR

[Jan Tojnar <jtojnar src gnome org>]

commit 9643dbba76f844adab25ca8d1ee0c224ff99ab19
Author: Jan Tojnar <jtojnar gmail com>
Date:   Sat May 21 13:59:25 2022 +0200

    Support multiple directories in GSETTINGS_SCHEMA_DIR
    
    Bring in line with GLib:
    https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1315

 editor/source-manager.vala | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/editor/source-manager.vala b/editor/source-manager.vala
index 27b2b17a..52fe02dd 100644
--- a/editor/source-manager.vala
+++ b/editor/source-manager.vala
@@ -122,8 +122,11 @@ private class SourceManager : Object
         string user_data_dir = GLib.Environment.get_user_data_dir ();
         source = try_prepend_dir (source, Path.build_filename (user_data_dir, "glib-2.0", "schemas"));
         string? var_schema_dir = GLib.Environment.get_variable ("GSETTINGS_SCHEMA_DIR");
-        if (var_schema_dir != null)
-            source = try_prepend_dir (source, (!) var_schema_dir);
+        if (var_schema_dir != null) {
+            string[] extra_schema_dirs = ((!) var_schema_dir).split (Path.SEARCHPATH_SEPARATOR_S);
+            for (int i = system_data_dirs.length - 1; i >= 0; i--)
+                source = try_prepend_dir (source, extra_schema_dirs[i]);
+        }
         return source;
     }