[network-manager-applet] shared/compat: fix memory handling of nm_setting_vpn_get_*_keys()

[Thomas Haller <thaller src gnome org>]

commit a52ccb2fe170558fc0aab4dd1d15ba8808b10951
Author: Jan Alexander Steffens (heftig) <jan steffens gmail com>
Date:   Thu Dec 21 20:36:48 2017 +0100

    shared/compat: fix memory handling of nm_setting_vpn_get_*_keys()
    
    The previous fix was bad because the keys do not come from NMSettingVpn's hash
    table but are copies that are freed by nm_setting_vpn_foreach_* before
    it returns.
    
    [thaller redhat com: import shared code from NetworkManager, merging
    three patches together.]
    
    Fixes: e93ca7fc129ec0f29f5313a3aa12839914df8fa2
    Fixes: 0c90e08f77b71d2bda699cf032fceec0122bbf82
    
    https://mail.gnome.org/archives/networkmanager-list/2017-December/msg00069.html
    https://mail.gnome.org/archives/networkmanager-list/2017-December/msg00070.html

 shared/nm-utils/nm-compat.c |   29 ++++++++++++++++++++++-------
 1 files changed, 22 insertions(+), 7 deletions(-)
---
diff --git a/shared/nm-utils/nm-compat.c b/shared/nm-utils/nm-compat.c
index 47035e6..90328c0 100644
--- a/shared/nm-utils/nm-compat.c
+++ b/shared/nm-utils/nm-compat.c
@@ -30,7 +30,7 @@ _get_keys_cb (const char *key, const char *val, gpointer user_data)
 {
        GPtrArray *a = user_data;
 
-       g_ptr_array_add (a, (gpointer) key);
+       g_ptr_array_add (a, g_strdup (key));
 }
 
 static const char **
@@ -40,22 +40,37 @@ _get_keys (NMSettingVpn *setting,
 {
        guint len;
        const char **keys = NULL;
-       gs_unref_ptrarray GPtrArray *a = NULL;
+       GPtrArray *a;
 
        nm_assert (NM_IS_SETTING_VPN (setting));
 
-       a = g_ptr_array_new ();
+       if (is_secrets)
+               len = nm_setting_vpn_get_num_secrets (setting);
+       else
+               len = nm_setting_vpn_get_num_data_items (setting);
+
+       a = g_ptr_array_sized_new (len + 1);
+
        if (is_secrets)
                nm_setting_vpn_foreach_secret (setting, _get_keys_cb, a);
        else
                nm_setting_vpn_foreach_data_item (setting, _get_keys_cb, a);
-       len = a->len;
 
-       if (a->len) {
+       len = a->len;
+       if (len) {
                g_ptr_array_sort (a, nm_strcmp_p);
                g_ptr_array_add (a, NULL);
-               keys = (const char **) g_ptr_array_free (g_steal_pointer (&a), FALSE);
-       }
+               keys = g_memdup (a->pdata, a->len * sizeof (gpointer));
+
+               /* we need to cache the keys *somewhere*. */
+               g_object_set_qdata_full (G_OBJECT (setting),
+                                        is_secrets
+                                        ? NM_CACHED_QUARK ("libnm._nm_setting_vpn_get_secret_keys")
+                                        : NM_CACHED_QUARK ("libnm._nm_setting_vpn_get_data_keys"),
+                                        g_ptr_array_free (a, FALSE),
+                                        (GDestroyNotify) g_strfreev);
+       } else
+               g_ptr_array_free (a, TRUE);
 
        NM_SET_OUT (out_length, len);
        return keys;