[master] dig +trace could fail when retrying with TCP

3770.	[bug]		"dig +trace" could fail with an assertion when it
			needed to fall back to TCP due to a truncated
			response. [RT #24660]

CHANGES

@@ -1,3 +1,7 @@
+3770.	[bug]		"dig +trace" could fail with an assertion when it
+			needed to fall back to TCP due to a truncated
+			response. [RT #24660]
+
 3769.	[doc]		Improved documentation of "rndc signing -list".
 			[RT #30652]
 

bin/dig/dighost.c

@@ -811,6 +811,7 @@ make_empty_lookup(void) {
 #ifdef ISC_PLATFORM_USESIT
 	looknew->sitvalue = NULL;
 #endif
+	dns_fixedname_init(&looknew->fdomain);
 	ISC_LINK_INIT(looknew, link);
 	ISC_LIST_INIT(looknew->q);
 	ISC_LIST_INIT(looknew->connecting);
@@ -899,6 +900,9 @@ clone_lookup(dig_lookup_t *lookold, isc_boolean_t servers) {
 		memmove(looknew->ecs_addr, lookold->ecs_addr, len);
 	}
 
+	dns_name_copy(dns_fixedname_name(&lookold->fdomain),
+		      dns_fixedname_name(&looknew->fdomain), NULL);
+
 	if (servers)
 		clone_server_list(lookold->my_server_list,
 				  &looknew->my_server_list);
@@ -1883,7 +1887,6 @@ followup_lookup(dns_message_t *msg, dig_query_t *query, dns_section_t section)
 				lookup->trace_root = ISC_FALSE;
 				if (lookup->ns_search_only)
 					lookup->recurse = ISC_FALSE;
-				dns_fixedname_init(&lookup->fdomain);
 				domain = dns_fixedname_name(&lookup->fdomain);
 				dns_name_copy(name, domain, NULL);
 			}