Index: avahi-core/dns.c
===================================================================
--- avahi-core/dns.c	(revision 1492)
+++ avahi-core/dns.c	(revision 1497)
@@ -153,6 +153,19 @@
     avahi_dns_packet_set_field(p, idx, avahi_dns_packet_get_field(p, idx) + 1);
 }   
 
+
+static void name_table_cleanup(void *key, void *value, void *user_data) {
+    AvahiDnsPacket *p = user_data;
+    
+    if ((uint8_t*) value >= AVAHI_DNS_PACKET_DATA(p) + p->size)
+        avahi_hashmap_remove(p->name_table, key);
+}
+
+void avahi_dns_packet_cleanup_name_table(AvahiDnsPacket *p) {
+    if (p->name_table)
+        avahi_hashmap_foreach(p->name_table, name_table_cleanup, p);
+}
+
 uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) {
     uint8_t *d, *saved_ptr = NULL;
     size_t saved_size;
@@ -216,6 +229,8 @@
 
 fail:
     p->size = saved_size;
+    avahi_dns_packet_cleanup_name_table(p);
+
     return NULL;
 }
 
@@ -685,6 +700,8 @@
         !avahi_dns_packet_append_uint16(p, k->type) ||
         !avahi_dns_packet_append_uint16(p, k->clazz | (unicast_response ? AVAHI_DNS_UNICAST_RESPONSE : 0))) {
         p->size = size;
+        avahi_dns_packet_cleanup_name_table(p);
+
         return NULL;
     }
 
@@ -799,6 +816,8 @@
 
 fail:
     p->size = size;
+    avahi_dns_packet_cleanup_name_table(p);
+
     return NULL;
 }
 
Index: avahi-core/dns.h
===================================================================
--- avahi-core/dns.h	(revision 1492)
+++ avahi-core/dns.h	(revision 1497)
@@ -52,6 +52,8 @@
 
 uint8_t *avahi_dns_packet_extend(AvahiDnsPacket *p, size_t l);
 
+void avahi_dns_packet_cleanup_name_table(AvahiDnsPacket *p);
+
 uint8_t *avahi_dns_packet_append_uint16(AvahiDnsPacket *p, uint16_t v);
 uint8_t *avahi_dns_packet_append_uint32(AvahiDnsPacket *p, uint32_t v);
 uint8_t *avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name);