[libglnx] Backport g_autoptr support for GString

[Alexander Larsson <alexl src gnome org>]

commit 7310bbdb58379fa4e6d7ec99aa89c2b069814335
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Sep 24 15:28:21 2015 +0200

    Backport g_autoptr support for GString

 glnx-backport-autocleanups.h |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/glnx-backport-autocleanups.h b/glnx-backport-autocleanups.h
index 472c865..f2bc483 100644
--- a/glnx-backport-autocleanups.h
+++ b/glnx-backport-autocleanups.h
@@ -31,6 +31,13 @@ g_autoptr_cleanup_generic_gfree (void *p)
     g_free (*pp);
 }
 
+static inline void
+g_autoptr_cleanup_gstring_free (GString *string)
+{
+  if (string)
+    g_string_free (string, TRUE);
+}
+
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GAsyncQueue, g_async_queue_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GBookmarkFile, g_bookmark_file_free)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GBytes, g_bytes_unref)
@@ -48,6 +55,7 @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(GPtrArray, g_ptr_array_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GMainContext, g_main_context_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GMainLoop, g_main_loop_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GSource, g_source_unref)
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GString, g_autoptr_cleanup_gstring_free)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GMappedFile, g_mapped_file_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GMarkupParseContext, g_markup_parse_context_unref)
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(gchar, g_free)