BESEN bug on String index named properties

BESEN-String-index-named-properties.js

/**
 * BESEN bug on String index named properties
 *  
 * There are some problems accessing the named properties of String 
 * objects that correspond to the individual characters of its
 * [[PrimitiveValue]].
 *
 * Tested on BESEN r117
 */


// When we use a String value, it doesn't work if the Expression  
// of the bracket notation property accessor holds directly a
// Numeric Literal:

var str = 'ab', i = 0;

// This fails:
print(str[0]);   //  undefined

// But the following works: 
print(str[i]);   // 'a' , OK
print(str['0']); // 'a' , OK
print(str[{ toString:function(){ return 0; } }]); // 'a', also OK


// With a String object, the properties are not accessible at all: 
str = new String("ab");

print(str[0]);   //  undefined
print(str[i]);   // undefined
print(str['0']); // undefined
print(str[{ toString:function(){ return 0; } }]); // undefined

// However the own properties are there, and their descriptor looks good:
print(str.hasOwnProperty('0')); // true      
print(JSON.stringify(Object.getOwnPropertyDescriptor(str, '0')));
// {"value":"a","writable":false,"enumerable":true,"configurable":false}

print(str.hasOwnProperty('1')); // true
print(JSON.stringify(Object.getOwnPropertyDescriptor(str, '1')));
// {"value":"b","writable":false,"enumerable":true,"configurable":false}

// Also, the following should be taken in consideration, if we add a
// property to the String.prototype object:

String.prototype['0'] = 'X';

// Even if the own property exist, and due they are not accessible 
// the String.prototype member is directly accessible:
 
print(str[0]);   // "X"
print(str[i]);   // "X"
print(str['0']); // "X"
print(str[{toString:function(){ return 0;} }]); // "X"