Key collisions for non-identical strings

[inexorabletash]

The userData API storage mechanism uses HTML attributes to store key/values; attribute names are case-insensitive. The cleanKey mechanism maps all non-attribute characters to "-". Together, this means that the following keys would be treated as the same:

"A-B-C"
"a-b-c"
"a%b*c"

This could lead to data overwrites if arbitrary keys are used.

Here's one possible key escaping mechanism to avoid this:

function (key) {
key = String(key);
var m = ['k'], len = key.length;
for (var i = 0; i < len; ++i) {
m.push(key.charCodeAt(i).toString(36));
}
return m.join('-');
}