[master] Check failover pools per peer in test mode

    Merges in rt29892

RELNOTES

@@ -1102,6 +1102,11 @@ by Eric Young (eay@cryptsoft.com).
   at TDS Telecom for reporting this issue.
   [ISC-Bugs #35378]
 
+- The server now detects failover peers that are not referenced in at least
+  one pool when run with the command line option for test mode, -T.  Prior to
+  this the check was performed too far down stream to be detected in test mode.
+  [ISC-Bugs #29892]
+
 			Changes since 4.2.0 (new features)
 
 - If a client renews before 'dhcp-cache-threshold' percent of its lease

includes/dhcpd.h

@@ -3540,6 +3540,7 @@ void free_everything (void);
 /* failover.c */
 #if defined (FAILOVER_PROTOCOL)
 extern dhcp_failover_state_t *failover_states;
+void dhcp_failover_sanity_check (void);
 void dhcp_failover_startup (void);
 int dhcp_failover_write_all_states (void);
 isc_result_t enter_failover_peer (dhcp_failover_state_t *);

server/dhcpd.c

@@ -820,6 +820,10 @@ main(int argc, char **argv) {
 
 	postconf_initialization (quiet);
 
+#if defined (FAILOVER_PROTOCOL)
+	dhcp_failover_sanity_check();
+#endif
+
 #if defined(DHCPv6) && defined(DHCP4o6)
 	if (dhcpv4_over_dhcpv6) {
 		if ((local_family == AF_INET) && (interfaces != NULL))