[gedit] Fixes #143 - close without saving button color

[Jordi Mas <jmas src gnome org>]

commit cb4db9fc5b6151897a8bf0b4ea0a57a4b9f4ff10
Author: Jordi Mas <jmas softcatala org>
Date:   Mon Apr 8 22:49:40 2019 +0200

    Fixes #143 - close without saving button color

 gedit/gedit-close-confirmation-dialog.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)
---
diff --git a/gedit/gedit-close-confirmation-dialog.c b/gedit/gedit-close-confirmation-dialog.c
index 85af73fff..0fdebfe95 100644
--- a/gedit/gedit-close-confirmation-dialog.c
+++ b/gedit/gedit-close-confirmation-dialog.c
@@ -273,10 +273,16 @@ gedit_close_confirmation_dialog_new_single (GtkWindow     *parent,
 static void
 add_buttons (GeditCloseConfirmationDialog *dlg)
 {
-       gtk_dialog_add_buttons (GTK_DIALOG (dlg),
-                               _("Close _without Saving"), GTK_RESPONSE_NO,
-                               _("_Cancel"), GTK_RESPONSE_CANCEL,
-                               NULL);
+        GtkWidget *close_button;
+
+        close_button = gtk_dialog_add_button (GTK_DIALOG (dlg),
+                                              _("Close _without Saving"),
+                                              GTK_RESPONSE_NO);
+
+        gtk_style_context_add_class (gtk_widget_get_style_context (close_button),
+                                     "destructive-action");
+
+       gtk_dialog_add_button (GTK_DIALOG (dlg), _("_Cancel"), GTK_RESPONSE_CANCEL);
 
        if (dlg->disable_save_to_disk)
        {