[meld/ui-next] test: Avoid loading icons from theme in a test

[Kai Willadsen <kaiw src gnome org>]

commit cf815065623936d9557fb19c006d58112c002704
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Mar 24 10:25:44 2019 +1000

    test: Avoid loading icons from theme in a test
    
    This is really another attempt at working out what the segfault is...

 test/test_gutterrendererchunk.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)
---
diff --git a/test/test_gutterrendererchunk.py b/test/test_gutterrendererchunk.py
index 6a11e6de..ef9827cf 100644
--- a/test/test_gutterrendererchunk.py
+++ b/test/test_gutterrendererchunk.py
@@ -60,12 +60,13 @@ def test_classify_change_actions(mode, editable, chunk, expected_action):
 
     source_editable, target_editable = editable
 
-    renderer = ActionGutter()
-    renderer._source_view = mock.Mock()
-    renderer._source_view.get_editable.return_value = source_editable
-    renderer._target_view = mock.Mock()
-    renderer._target_view.get_editable.return_value = target_editable
-    renderer.action_mode = mode
+    with mock.patch.object(ActionGutter, 'icon_direction'):
+        renderer = ActionGutter()
+        renderer._source_view = mock.Mock()
+        renderer._source_view.get_editable.return_value = source_editable
+        renderer._target_view = mock.Mock()
+        renderer._target_view.get_editable.return_value = target_editable
+        renderer.action_mode = mode
 
-    action = renderer._classify_change_actions(chunk)
-    assert action == expected_action
+        action = renderer._classify_change_actions(chunk)
+        assert action == expected_action