File fix_gtk_popover_on_3.20.patch of Package libreoffice.22255

diff --git a/vcl/unx/gtk3/gtkinst.cxx b/vcl/unx/gtk3/gtkinst.cxx
index 6b592b3..2fce9eb 100644
--- a/vcl/unx/gtk3/gtkinst.cxx
+++ b/vcl/unx/gtk3/gtkinst.cxx
@@ -21415,12 +21415,16 @@ public:
         gtk_popover_set_relative_to(m_pPopover, pWidget);
 #endif
         gtk_popover_set_pointing_to(m_pPopover, &aRect);
-        gtk_popover_popup(m_pPopover);
+        // in GTK 3.22 you can just call gtk_popover_popup() to get it to show with transitions,
+        // but on SLE-12-SP5 we just have GTK 3.20, so enable transitions and show it to get the
+        // same effect
+        gtk_popover_set_transitions_enabled(m_pPopover, true);
+        gtk_widget_show(GTK_WIDGET(m_pPopover));
     }
 
     virtual void popdown() override
     {
-        gtk_popover_popdown(m_pPopover);
+        gtk_widget_hide(GTK_WIDGET(m_pPopover));
     }
 
     virtual ~GtkInstancePopover() override