BUG/MEDIUM: stick-table: Wrong stick-table backends parsing.

When parsing references to stick-tables declared as backends, they are added to
a list of proxies (they are proxies!) which refer to this stick-tables.
Before this patch we added them to these list without checking they were already
present, making the silly hypothesis the actions/sample were checked/resolved in the same
order the proxies are parsed.

This patch implement a simple inline function to in_proxies_list() to test
the presence of a proxy in a list of proxies. We use this function when resolving
/checking samples/actions.

This bug was introduced by 015e4d7 commit.

Must be backported to 2.0.

include/proto/proxy.h

@@ -184,6 +184,21 @@ static inline int l7_status_match(struct proxy *p, int status)
 	}
 	return 0;
 }
+
+/* Return 1 if <p> proxy is in <list> list of proxies which are also stick-tables,
+ * 0 if not.
+ */
+static inline int in_proxies_list(struct proxy *list, struct proxy *proxy)
+{
+	struct proxy *p;
+
+	for (p = list; p; p = p->next_stkt_ref)
+		if (proxy == p)
+			return 1;
+
+	return 0;
+}
+
 #endif /* _PROTO_PROXY_H */
 
 /*

src/action.c

@@ -56,7 +56,7 @@ int check_trk_action(struct act_rule *rule, struct proxy *px, char **err)
 		return 0;
 	}
 	else {
-		if (target->proxies_list != px) {
+		if (!in_proxies_list(target->proxies_list, px)) {
 			px->next_stkt_ref = target->proxies_list;
 			target->proxies_list = px;
 		}

src/sample.c

@@ -1274,7 +1274,7 @@ int smp_resolve_args(struct proxy *p)
 				break;
 			}
 
-			if (t->proxies_list != p) {
+			if (!in_proxies_list(t->proxies_list, p)) {
 				p->next_stkt_ref = t->proxies_list;
 				t->proxies_list = p;
 			}