get_address_info: don't allow duplicate entries to be returned in the list

OS-X's getaddrinfo() can return duplicate entries (and does for localhost with
the default 10.5 /etc/hosts).  This caused some annoying crashes which this
patch takes care of.

See http://trac.macosforge.org/projects/xquartz/ticket/44

1 files changed, 9 insertions, 1 deletions

diff --git a/gethost.c b/gethost.c
index a0f30da..94c1d99 100644
--- a/gethost.c
+++ b/gethost.c
@@ -307,7 +307,15 @@ struct addrlist *get_address_info (
 		family = FamilyInternet6;
 	    }
 
-	    if (len > 0 && src != NULL) {
+	    struct addrlist *duplicate;
+	    for(duplicate = retval; duplicate != NULL; duplicate = duplicate->next) {
+		if(duplicate->family == family && duplicate->len == len &&
+                   memcmp(duplicate->address, src, len) == 0) {
+		    break;
+                }
+	    }
+
+	    if (len > 0 && src != NULL && duplicate == NULL) {
 		struct addrlist *newrv = malloc (sizeof(struct addrlist));
 		if (newrv) {
 		    newrv->address = malloc (len);