[perl-Gtk3] Fix a test failure in t/zz-GdkEvent.t

[Torsten Schönfeld <tsch src gnome org>]

commit ff8668314d19081658b0ce5dc3f8e70db3210423
Author: Torsten Schönfeld <kaffeetisch gmx de>
Date:   Sun Aug 2 16:58:12 2015 +0200

    Fix a test failure in t/zz-GdkEvent.t
    
    It wasn't protecting some event alias tests with appropriate version
    checks.

 t/zz-GdkEvent.t |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)
---
diff --git a/t/zz-GdkEvent.t b/t/zz-GdkEvent.t
index 0eece8f..859a43b 100644
--- a/t/zz-GdkEvent.t
+++ b/t/zz-GdkEvent.t
@@ -119,9 +119,7 @@ SKIP: {
 
 # Button #######################################################################
 
-foreach (qw/triple-button-press
-            3button-press
-            double-button-press
+foreach (qw/3button-press
             2button-press
             button-press/)
 {
@@ -129,6 +127,18 @@ foreach (qw/triple-button-press
           'Gtk3::Gdk::EventButton', "Gtk3::Gdk::Event->new $_");
 }
 
+SKIP: {
+  skip 'aliases', 2
+    unless Gtk3::CHECK_VERSION (3, 6, 0);
+  foreach (qw/triple-button-press
+              double-button-press/)
+  {
+    isa_ok ($event = Gtk3::Gdk::Event->new ($_),
+            'Gtk3::Gdk::EventButton', "Gtk3::Gdk::Event->new $_");
+  }
+}
+
+$event = Gtk3::Gdk::Event->new ('button-press');
 fields_ok ($event, time => 42,
                    x => 13,
                    y => 14,