[epiphany] Drop "Help" entry in Pantheon

[Jan-Michael Brummer <jbrummer src gnome org>]

commit 2a453024fe4c237261a4b5e59e2ddacc74ad0674
Author: Jan-Michael Brummer <jan brummer tabos org>
Date:   Wed Dec 19 11:28:16 2018 +0100

    Drop "Help" entry in Pantheon
    
    Add check for pantheon desktop function and remove help entry if needed
    
    Fixes: https://gitlab.gnome.org/GNOME/epiphany/issues/71

 src/ephy-header-bar.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/src/ephy-header-bar.c b/src/ephy-header-bar.c
index f169c0548..c7f3fcc9a 100644
--- a/src/ephy-header-bar.c
+++ b/src/ephy-header-bar.c
@@ -138,6 +138,14 @@ update_revealer_visibility (GtkRevealer *revealer)
                           gtk_revealer_get_child_revealed (revealer));
 }
 
+static gboolean
+is_desktop_pantheon (void)
+{
+  const gchar *xdg_current_desktop = g_environ_getenv (g_get_environ (), "XDG_CURRENT_DESKTOP");
+
+  return strstr (xdg_current_desktop, "Pantheon") != NULL;
+}
+
 static void
 ephy_header_bar_constructed (GObject *object)
 {
@@ -224,7 +232,11 @@ ephy_header_bar_constructed (GObject *object)
     gtk_widget_destroy (GTK_WIDGET (gtk_builder_get_object (builder, "save-as-application-separator")));
     gtk_widget_destroy (GTK_WIDGET (gtk_builder_get_object (builder, "save-as-application-button")));
     gtk_widget_destroy (GTK_WIDGET (gtk_builder_get_object (builder, "application-manager-button")));
+
+    if (is_desktop_pantheon ())
+      gtk_widget_destroy (GTK_WIDGET (gtk_builder_get_object (builder, "help-button")));
   }
+
   gtk_menu_button_set_popover (GTK_MENU_BUTTON (button), page_menu_popover);
   g_object_unref (builder);