Possible null dereference

[VoroninArtemii]

There is a possible null dereference in this line.

polkit/src/polkitbackend/polkitbackendsessionmonitor-systemd.c

Line 76 in 7a1cff6

ret = (*callback) (user_data);

We check the variable callback before it but only write it to the logs if callback is NULL.

polkit/src/polkitbackend/polkitbackendsessionmonitor-systemd.c

Line 74 in 7a1cff6

g_warn_if_fail (callback != NULL);

Found by Linux Verification Center (portal.linuxtesting.ru) with SVACE.
Author A. Voronin.