gbinding: warn on failed value transformation

GBinding warned if g_value_transform() returned FALSE, but it didn't
warn if there was no transformation available at all. Fix that and
test it.

https://bugzilla.gnome.org/show_bug.cgi?id=726574

2 files changed, 31 insertions, 7 deletions

diff --git a/gobject/gbinding.c b/gobject/gbinding.c
index 0e17b898b..2237e5e5d 100644
--- a/gobject/gbinding.c
+++ b/gobject/gbinding.c
@@ -294,15 +294,15 @@ default_transform (const GValue *value_a,
         {
           if (g_value_transform (value_a, value_b))
             goto done;
+        }
 
-          g_warning ("%s: Unable to convert a value of type %s to a "
-                     "value of type %s",
-                     G_STRLOC,
-                     g_type_name (G_VALUE_TYPE (value_a)),
-                     g_type_name (G_VALUE_TYPE (value_b)));
+      g_warning ("%s: Unable to convert a value of type %s to a "
+                 "value of type %s",
+                 G_STRLOC,
+                 g_type_name (G_VALUE_TYPE (value_a)),
+                 g_type_name (G_VALUE_TYPE (value_b)));
 
-          return FALSE;
-        }
+      return FALSE;
     }
   else
     g_value_copy (value_a, value_b);
diff --git a/gobject/tests/binding.c b/gobject/tests/binding.c
index 5f87e84ef..f79640b99 100644
--- a/gobject/tests/binding.c
+++ b/gobject/tests/binding.c
@@ -612,6 +612,29 @@ binding_unbind (void)
   g_object_unref (target);
 }
 
+static void
+binding_fail (void)
+{
+  BindingSource *source = g_object_new (binding_source_get_type (), NULL);
+  BindingTarget *target = g_object_new (binding_target_get_type (), NULL);
+  GBinding *binding;
+
+  /* double -> boolean is not supported */
+  binding = g_object_bind_property (source, "value",
+                                    target, "toggle",
+                                    G_BINDING_DEFAULT);
+  g_object_add_weak_pointer (G_OBJECT (binding), (gpointer *) &binding);
+
+  g_test_expect_message ("GLib-GObject", G_LOG_LEVEL_WARNING,
+                         "*Unable to convert*double*boolean*");
+  g_object_set (source, "value", 1.0, NULL);
+  g_test_assert_expected_messages ();
+
+  g_object_unref (source);
+  g_object_unref (target);
+  g_assert (binding == NULL);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -629,6 +652,7 @@ main (int argc, char *argv[])
   g_test_add_func ("/binding/invert-boolean", binding_invert_boolean);
   g_test_add_func ("/binding/same-object", binding_same_object);
   g_test_add_func ("/binding/unbind", binding_unbind);
+  g_test_add_func ("/binding/fail", binding_fail);
 
   return g_test_run ();
 }