Define and use cleanup helpers for libarchive

This should fix some of the ASAN leaks around libarchive usage,
and is generally better.

Closes: #609
Approved by: jlebon

src/libostree/ostree-libarchive-input-stream.h

@@ -23,6 +23,7 @@
 #pragma once
 
 #include <gio/gio.h>
+#include "ostree-libarchive-private.h"
 
 G_BEGIN_DECLS
 

src/libostree/ostree-libarchive-private.h

@@ -0,0 +1,42 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2016 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Alexander Larsson <alexl@redhat.com>
+ */
+
+#pragma once
+
+#include <gio/gio.h>
+#include "libglnx.h"
+#ifdef HAVE_LIBARCHIVE
+#include <archive.h>
+#include <archive_entry.h>
+#endif
+
+G_BEGIN_DECLS
+
+#ifdef HAVE_LIBARCHIVE
+GLNX_DEFINE_CLEANUP_FUNCTION (void *, flatpak_local_free_write_archive, archive_write_free)
+#define ot_cleanup_write_archive __attribute__((cleanup (flatpak_local_free_write_archive)))
+
+GLNX_DEFINE_CLEANUP_FUNCTION (void *, flatpak_local_free_read_archive, archive_read_free)
+#define ot_cleanup_read_archive __attribute__((cleanup (flatpak_local_free_read_archive)))
+#endif
+
+G_END_DECLS

src/libostree/ostree-repo-libarchive.c

@@ -913,10 +913,9 @@ ostree_repo_write_archive_to_mtree (OstreeRepo                *self,
 {
 #ifdef HAVE_LIBARCHIVE
   gboolean ret = FALSE;
-  struct archive *a = NULL;
+  ot_cleanup_read_archive struct archive *a = archive_read_new ();
   OstreeRepoImportArchiveOptions opts = { 0, };
 
-  a = archive_read_new ();
 #ifdef HAVE_ARCHIVE_READ_SUPPORT_FILTER_ALL
   archive_read_support_filter_all (a);
 #else
@@ -945,7 +944,6 @@ ostree_repo_write_archive_to_mtree (OstreeRepo                *self,
   if (a)
     {
       (void)archive_read_close (a);
-      (void)archive_read_free (a);
     }
   return ret;
 #else