Closed Bug 1145326 Opened 5 years ago Closed 5 years ago

String.prototype.normalize error when normalization form parameter is not an atom


(Core :: JavaScript: Internationalization API, defect)

37 Branch
Not set



Tracking Status
firefox39 --- fixed


(Reporter: pathall, Assigned: evilpie)



(2 files)

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:37.0) Gecko/20100101 Firefox/37.0
Build ID: 20150305191659

Steps to reproduce:

Assume a button with an id of "NFKC":

<button id="NFKC">NFKC</button>

Stick that string in a variable:

var s1 = document.body.querySelector('#NFKC').id

By way of comparison, assign the very same string to a variable directly:

var s2 = 'NFKC'

So of course:

s1 === s2
// true


s1 == s2
// true

To normalize a string, you pass one of NFC, NFD, NFKC, or NFKD to .normalize(), like this:

// "á"

Depending on the normalization form you choose, you get different codepoints:

'á'.normalize('NFC').length == 1
// true
'á'.normalize('NFD').length == 2
// true

Actual results:

Since we know that s1 (the string we retrieved from the DOM) and s2 are THE SAME STRING (s1 === s2 is true), then obviously we can use either to normalize a string:

// well yeah, because s2 IS 'NFKC'. 

Naturally, s1 will behave exactly the same way, right?

 // RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD'

Why the error here, but not with s2?

Expected results:

If I pass one of four strings corresponding to normalization forms to .normalize(), it should carry out normalization. Instead, I get a RangeError.
As pointed out on StackOverflow by Rick Hitchcock, the string doesn't have to be extracted from the DOM to cause the error:

    var s2 = 'NFKC'.split('').join('');
    var s2 = 'NFKCabc'.replace('abc','');

Rick points out that this version this doesn't: 

    var s2 = 'N'+'F'+'K'+'C';
Component: Untriaged → JavaScript: Internationalization API
Product: Firefox → Core
Assignee: nobody → evilpies
Summary: String.prototype.normalize error when normalization form parameter is from the DOM → String.prototype.normalize error when normalization form parameter is not an atom
So the problem here is that the form parameter can be a "linear string", but not an atom. And of course if it's not an atom the pointer comparison to any atom is always going to fail.
Ever confirmed: true
Attached patch normalizeSplinter Review
Attachment #8580637 - Flags: review?(jwalden+bmo)
Comment on attachment 8580637 [details] [diff] [review]

Review of attachment 8580637 [details] [diff] [review]:

Oh fail, how did I review that.  :-(
Attachment #8580637 - Flags: review?(jwalden+bmo) → review+
Closed: 5 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla39
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