Author: David Rheinsberg <david.rheinsberg@gmail.com>
Origin: backport, https://github.com/bus1/dbus-broker/commit/608b259e25ef1348b9e4a8e022c35b5c68d3df98
Description: util/user: keep reference to user in each usage table
 Keep a reference to an owning user in each usage table. We want to allow
 callers to hold charges without holding on to any user references.
 .
 Also fix the peer-deinitialization to be ordered correctly and free the
 user references last (in particular, after the charges). This is not
 strictly necessary, but now follows our coding style and would have
 avoided possible failures.
 .
 This fixes an assertion failure when disconnecting entire groups of
 peers of the same user, due to the recent fix that actually made
 peer-accounting do something.
--- a/src/bus/peer.c
+++ b/src/bus/peer.c
@@ -358,12 +358,12 @@
         name_owner_deinit(&peer->owned_names);
         policy_snapshot_free(peer->policy);
         connection_deinit(&peer->connection);
-        user_unref(peer->user);
         user_charge_deinit(&peer->charges[2]);
         user_charge_deinit(&peer->charges[1]);
         user_charge_deinit(&peer->charges[0]);
         free(peer->seclabel);
         free(peer->gids);
+        user_unref(peer->user);
         free(peer);
 
         close(fd);
--- a/src/util/user.c
+++ b/src/util/user.c
@@ -48,7 +48,7 @@
                 return error_origin(-ENOMEM);
 
         usage->n_refs = REF_INIT;
-        usage->user = user;
+        usage->user = user_ref(user);
         usage->uid = uid;
         usage->user_node = (CRBNode)C_RBNODE_INIT(usage->user_node);
 
@@ -64,6 +64,7 @@
                 c_assert(!usage->slots[i]);
 
         user_usage_unlink(usage);
+        user_unref(usage->user);
         free(usage);
 }