<para><function>sd_bus_error_get_errno</function> returns
<constant>false</constant> when <parameter>e</parameter> is
<constant>NULL</constant>, and a positive errno value mapped from
<para><function>sd_bus_error_get_errno</function> returns
<constant>false</constant> when <parameter>e</parameter> is
<constant>NULL</constant>, and a positive errno value mapped from