tests: Add testing for sideeffects of using CallsSettings

When setting up a binding between GSettings and GObject properties the
CallsSetting used to set the value from the GSetting to the property and
back to the GSetting.

While the value was still the default value it was marked as non default
because it had explicitly been set without any user interaction.

tests/meson.build

@@ -193,4 +193,17 @@ t = executable('contacts', test_sources,
                )
 test('contacts', t, env: test_env)
 
+test_sources = [ 'test-settings.c' ]
+t = executable('settings', test_sources,
+               c_args : test_cflags,
+               link_args: test_link_args,
+               pie: true,
+               link_with : [calls_vala, libcalls],
+               dependencies: calls_deps,
+               include_directories : [
+                   calls_includes,
+                 ]
+               )
+test('settings', t, env: test_env)
+
 endif