dialer: fix setting of number property

The number property is currently being overwritten, meaning any excess
characters in the previous number will remain.  To fix this, we assign
instead.  And add some tests to check.

src/hdy-dialer.c

@@ -168,7 +168,7 @@ hdy_dialer_set_property (GObject      *object,
 
   switch (property_id) {
   case PROP_NUMBER:
-    g_string_overwrite (priv->number, 0, g_value_get_string (value));
+    g_string_assign (priv->number, g_value_get_string (value));
     break;
 
   default:
@@ -392,6 +392,6 @@ hdy_dialer_set_number (HdyDialer  *self,
 {
   HdyDialerPrivate *priv = hdy_dialer_get_instance_private (self);
 
-  g_string_overwrite (priv->number, 0, newnumber);
+  g_string_assign (priv->number, newnumber);
   g_object_notify_by_pspec (G_OBJECT (self), props[PROP_NUMBER]);
 }

tests/test-dialer.c

@@ -30,6 +30,15 @@ test_hdy_dialer_setnumber(void)
   hdy_dialer_set_number(HDY_DIALER (dialer), "#1234");
   g_assert_cmpstr("#1234", ==, hdy_dialer_get_number(HDY_DIALER (dialer)));
   g_assert_cmpint(1, ==, notified);
+
+  /* Check that we're assigning to the string and not overwriting */
+  hdy_dialer_set_number(HDY_DIALER (dialer), "#123");
+  g_assert_cmpstr("#1234", !=, hdy_dialer_get_number(HDY_DIALER (dialer)));
+
+  /* Do the same using the GObject property */
+  g_object_set(G_OBJECT (dialer), "number", "#12", NULL);
+  g_assert_cmpstr("#123", !=, hdy_dialer_get_number(HDY_DIALER (dialer)));
+  g_assert_cmpstr("#12", ==, hdy_dialer_get_number(HDY_DIALER (dialer)));
 }