gnu: Add gnome-tweak-tool.

* gnu/packages/patches/gnome-tweak-tool-search-paths.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/gnome.scm (gnome-tweak-tool): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

1 files changed, 52 insertions, 0 deletions

diff --git a/gnu/packages/patches/gnome-tweak-tool-search-paths.patch b/gnu/packages/patches/gnome-tweak-tool-search-paths.patch
new file mode 100644
index 0000000000..027c61b3af
--- /dev/null
+++ b/gnu/packages/patches/gnome-tweak-tool-search-paths.patch
@@ -0,0 +1,52 @@
+Gnome-tweak-tool does not look at GSETTINGS_SCHEMA_PATH or XDG_DATA_DIRS, it
+assumes that schemas are installed in one global directory
+(GSETTINGS_SCHEMA_DIR/gsettingsschemadir).
+
+Guix/GuixSD uses a different directory for every gir package and has
+packages pick-up files using XDG_DATA_DIRS.
+
+Upstream ticket: https://bugzilla.gnome.org/show_bug.cgi?id=764537
+janneke@gnu.org
+
+--- gnome-tweak-tool-3.18.1.orig/gtweak/gsettings.py	2015-04-08 15:21:32.000000000 +0200
++++ gnome-tweak-tool-3.18.1/gtweak/gsettings.py	2016-04-03 11:26:38.658482704 +0200
+@@ -16,7 +16,8 @@
+ # along with gnome-tweak-tool.  If not, see <http://www.gnu.org/licenses/>.
+ 
+ import logging
+-import os.path
++import os
++import sys
+ import xml.dom.minidom
+ import gettext
+ 
+@@ -31,6 +32,13 @@
+ class GSettingsMissingError(Exception):
+     pass
+ 
++def file_from_path(path, file_name):
++    for dir in path:
++        f = os.path.join(dir, file_name)
++        if os.path.exists(f):
++            return f
++    return None
++
+ class _GSettingsSchema:
+     def __init__(self, schema_name, schema_dir=None, schema_filename=None, **options):
+         if not schema_dir:
+@@ -38,9 +46,14 @@
+         if not schema_filename:
+             schema_filename = schema_name + ".gschema.xml"
+ 
++        schema_prefix = os.path.join('glib-2.0', 'schemas')
+         schema_path = os.path.join(schema_dir, schema_filename)
+         if not os.path.exists(schema_path):
+-            logging.critical("Could not find schema %s" % schema_path)
++            schema_path = file_from_path(os.environ.get ('GSETTINGS_SCHEMA_PATH', '').split(os.path.pathsep), schema_filename)
++        if not (schema_path and os.path.exists(schema_path)):
++            schema_path = file_from_path(os.environ.get ('XDG_DATA_DIRS', '').split(os.path.pathsep), os.path.join(schema_prefix, schema_filename))
++        if not (schema_path and os.path.exists(schema_path)):
++            logging.critical("Could not find schema %s" % schema_filename)
+             assert(False)
+ 
+         self._schema_name = schema_name