[gnome-builder] modeline: use g_slice_dup and steal language string

[Christian Hergert <chergert src gnome org>]

commit b71e62f6597bb19bd711e54d947820a7df751a84
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jan 3 02:16:43 2018 -0800

    modeline: use g_slice_dup and steal language string

 src/libide/modelines/modeline-parser.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/libide/modelines/modeline-parser.c b/src/libide/modelines/modeline-parser.c
index c520ea2..d79f5b9 100644
--- a/src/libide/modelines/modeline-parser.c
+++ b/src/libide/modelines/modeline-parser.c
@@ -799,9 +799,8 @@ modeline_parser_apply_modeline (GtkTextBuffer   *buffer,
        }
        else
        {
-               previous = g_slice_new (ModelineOptions);
-               *previous = options;
-               previous->language_id = g_strdup (options.language_id);
+               previous = g_slice_dup (ModelineOptions, &options);
+               previous->language_id = g_steal_pointer (&options.language_id);
 
                g_object_set_data_full (G_OBJECT (buffer),
                                        MODELINE_OPTIONS_DATA_KEY,