Silence gcc-10-fanalyzer false positive

Add REQUIRE(type == dns_rdatatype_nsec3 || firstp != NULL); so
that dereferences of *firstp is not flagged as a NULL pointer
dereference.

(cherry picked from commit 683ad6e4bd12315ace3703d56ba0f0a3b1ad660f)

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index 9d27a1519f9abe88e154e95e343ece4f3e757936..3ee18766cdb0c6100a070b5f25726c391bc46be2 100644 (file)
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -3874,6 +3874,7 @@ previous_closest_nsec(dns_rdatatype_t type, rbtdb_search_t *search,
        isc_result_t result;
 
        REQUIRE(nodep != NULL && *nodep == NULL);
+       REQUIRE(type == dns_rdatatype_nsec3 || firstp != NULL);
 
        if (type == dns_rdatatype_nsec3) {
                result = dns_rbtnodechain_prev(&search->chain, NULL, NULL);