overrides: Fix length parameter when passing non-ascii strings to Gtk.Builder.add_from_string/add_objects_from_string

It was passing the codepoint count instead of the length in bytes which lead to things
reading past the provided memory and crashes.

Also use the same code for Gtk.UIManager.add_ui_from_string()

Fixes #255

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/test_overrides_gtk.py b/tests/test_overrides_gtk.py
index 1e365525..c515e513 100644
--- a/tests/test_overrides_gtk.py
+++ b/tests/test_overrides_gtk.py
@@ -822,6 +822,30 @@ class TestBuilder(unittest.TestCase):
                             []),
         }
 
+    def test_add_from_string(self):
+        builder = Gtk.Builder()
+        builder.add_from_string(u"")
+        builder.add_from_string("")
+
+        def get_example(string):
+            return u"""\
+<interface>
+  <menu id="appmenu">
+    <section>
+      <item>
+        <attribute name="label">%s</attribute>
+      </item>
+    </section>
+  </menu>
+</interface>""" % string
+
+        builder.add_from_string(get_example(u"ä" * 1000))
+
+        builder = Gtk.Builder()
+        builder.add_objects_from_string(u"", [''])
+        builder.add_objects_from_string("", [''])
+        builder.add_objects_from_string(get_example(u"ä" * 1000), [''])
+
     def test_extract_handler_and_args_object(self):
         class Obj():
             pass