diff --git a/mysql-test/std_data/Index.xml b/mysql-test/std_data/Index.xml
index 3dc647d8195..b8f61d59203 100644
--- a/mysql-test/std_data/Index.xml
+++ b/mysql-test/std_data/Index.xml
@@ -8,6 +8,13 @@
+
+
+ a
+ b
+
+
+
diff --git a/mysys/charset.c b/mysys/charset.c
index d59be4ab6c7..b1b91d716ba 100644
--- a/mysys/charset.c
+++ b/mysys/charset.c
@@ -220,7 +220,8 @@ copy_uca_collation(CHARSET_INFO *to, CHARSET_INFO *from)
static int add_collation(CHARSET_INFO *cs)
{
if (cs->name && (cs->number ||
- (cs->number=get_collation_number_internal(cs->name))))
+ (cs->number=get_collation_number_internal(cs->name))) &&
+ cs->number < array_elements(all_charsets))
{
if (!all_charsets[cs->number])
{