[gtk] about dialog: Fix page visibility

[Matthias Clasen <matthiasc src gnome org>]

commit 1318d3748afba9ef8c476f05cca0516f885faeb7
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 12 18:19:36 2019 +0000

    about dialog: Fix page visibility
    
    The handling of page visibility broke when the dialog
    was ported to GtkStackPage in 52b83ac5530940bf17bc.
    
    Closes: https://gitlab.gnome.org/GNOME/gtk/issues/1877

 gtk/gtkaboutdialog.c     | 3 +--
 gtk/ui/gtkaboutdialog.ui | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkaboutdialog.c b/gtk/gtkaboutdialog.c
index 1105a966e9..d82e32a6e5 100644
--- a/gtk/gtkaboutdialog.c
+++ b/gtk/gtkaboutdialog.c
@@ -684,7 +684,7 @@ update_credits_button_visibility (GtkAboutDialog *about)
   gboolean show;
   GtkStackPage *page;
 
-  page = gtk_stack_get_page (GTK_STACK (priv->stack), priv->system_page);
+  page = gtk_stack_get_page (GTK_STACK (priv->stack), priv->credits_page);
 
   show = (priv->authors != NULL ||
           priv->documenters != NULL ||
@@ -2155,7 +2155,6 @@ add_credits_section (GtkAboutDialog  *about,
   gtk_widget_set_halign (label, GTK_ALIGN_END);
   gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
   gtk_grid_attach (grid, label, 0, *row, 1, 1);
-  gtk_widget_show (label);
 
   for (p = people; *p; p++)
     {
diff --git a/gtk/ui/gtkaboutdialog.ui b/gtk/ui/gtkaboutdialog.ui
index e339138a8a..c457a4ebd5 100644
--- a/gtk/ui/gtkaboutdialog.ui
+++ b/gtk/ui/gtkaboutdialog.ui
@@ -111,6 +111,7 @@
                 <child>
                   <object class="GtkStackPage">
                     <property name="name">credits</property>
+                    <property name="visible">0</property>
                     <property name="title" translatable="yes">Credits</property>
                     <property name="child">
                       <object class="GtkBox" id="credits_page">
@@ -147,6 +148,7 @@
                 <child>
                   <object class="GtkStackPage">
                     <property name="name">license</property>
+                    <property name="visible">0</property>
                     <property name="title" translatable="yes">License</property>
                     <property name="child">
                       <object class="GtkBox" id="license_page">
@@ -189,6 +191,7 @@
                 <child>
                   <object class="GtkStackPage">
                     <property name="name">system</property>
+                    <property name="visible">0</property>
                     <property name="title" translatable="yes">System</property>
                     <property name="child">
                       <object class="GtkBox" id="system_page">