crash when using associative array and integer variable

[Roman Rakus]

Repeated in the bash-4.0.38 and bash-4.1.7 by the script;
#!/bin/bash

typeset -Ai s
y='*'
z='['
s[$y]=1
s[$z]=2
(( s[$z] = s[$z] + ${s[$y]} ))
(( s[$y] = s[$y] + ${s[$z]} ))
[[ ${s[$y]} = 4  ]] && echo "ok"

----
FIX: added check;
diff -up bash-4.1/variables.c.Ai bash-4.1/variables.c
--- bash-4.1/variables.c.Ai     2010-07-28 08:42:54.000000000 +0200
+++ bash-4.1/variables.c        2010-07-28 08:43:17.000000000 +0200
@@ -2371,7 +2371,7 @@ bind_int_variable (lhs, rhs)
 #endif
     v = bind_variable (lhs, rhs, 0);

-  if (isint)
+  if (isint && v)
     VSETATTR (v, att_integer);

   return (v);

RR