sql_select.cc check for cond==NULL in add_ft_keys()

fulltext_left_join.result	BitKeeper file /usr/home/serg/Abk/mysql/mysql-test/r/fulltext_left_join.result
fulltext_left_join.test	BitKeeper file /usr/home/serg/Abk/mysql/mysql-test/t/fulltext_left_join.test

mysql-test/r/fulltext_left_join.result

+match(t1.texte,t1.sujet,t1.motsclefs) against('droit')
+0
+0
+0.67003110026735
+0

mysql-test/t/fulltext_left_join.test

+#
+# Test for bug from Jean-Cdric COSTA <jean-cedric.costa@ensmp.fr>
+#
+
+CREATE TABLE t1 (
+       id           VARCHAR(255) NOT NULL PRIMARY KEY,
+       sujet        VARCHAR(255),
+       motsclefs    TEXT,
+       texte        MEDIUMTEXT,
+       FULLTEXT(sujet, motsclefs, texte)
+);
+INSERT INTO t1 VALUES('123','toto','essai','test');
+INSERT INTO t1 VALUES('456','droit','penal','lawyer');
+INSERT INTO t1 VALUES('789','aaaaa','bbbbb','cccccc');
+CREATE TABLE t2 (
+       id         VARCHAR(255) NOT NULL,
+       author     VARCHAR(255) NOT NULL
+);
+INSERT INTO t2 VALUES('123', 'moi');
+INSERT INTO t2 VALUES('123', 'lui');
+INSERT INTO t2 VALUES('456', 'lui');
+
+select match(t1.texte,t1.sujet,t1.motsclefs) against('droit')
+       from t1 left join t2 on t2.id=t1.id;
+

sql/sql_select.cc

@@ -1329,6 +1329,9 @@ add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
 {
   Item_func_match *cond_func=NULL;
 
+  if (!cond)
+    return;
+
   if (cond->type() == Item::FUNC_ITEM)
   {
     Item_func *func=(Item_func *)cond,