From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Fri, 1 Apr 2022 10:10:22 +0000 (+0300)
Subject: lib-dns: dns_lookup*() - Assert that at least one IP is returned on success
X-Git-Tag: 2.4.0~4121
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=2ac7728f4a298bc513d6f94f8a0a1bfddf25ab5c;p=thirdparty%2Fdovecot%2Fcore.git

lib-dns: dns_lookup*() - Assert that at least one IP is returned on success
---

diff --git a/src/lib-dns/dns-lookup.c b/src/lib-dns/dns-lookup.c
index 0cb56325cd..393015f212 100644
--- a/src/lib-dns/dns-lookup.c
+++ b/src/lib-dns/dns-lookup.c
@@ -306,6 +306,7 @@ static void dns_lookup_callback(struct dns_lookup *lookup)
 		e->add_str("cached", lookup->cached ? "yes" : "no");
 		e_debug(e->event(), "Lookup successful after %u msecs",
 			lookup->result.msecs);
+		i_assert(lookup->ptr_lookup || lookup->result.ips_count > 0);
 	}
 	lookup->callback(&lookup->result, lookup->context);
 }
diff --git a/src/lib-dns/dns-lookup.h b/src/lib-dns/dns-lookup.h
index 549bc9f053..7df1786758 100644
--- a/src/lib-dns/dns-lookup.h
+++ b/src/lib-dns/dns-lookup.h
@@ -30,7 +30,7 @@ struct dns_lookup_result {
 	unsigned int msecs;
 
 	/* for IP lookup: */
-	unsigned int ips_count;
+	unsigned int ips_count; /* guaranteed to be >0 on success */
 	const struct ip_addr *ips;
 	/* for PTR lookup: */
 	const char *name;