1378782 - Incorrect Upper Case Mapping Of Unicode Characters '\ufb06' & '\ufb05'

Status: RESOLVED DUPLICATE of bug 1318403

(Core :: JavaScript Engine, defect)

Description

[Rakesh]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170628075643
Firefox for Android

Steps to reproduce:

Open console and run below statements :

'\ufb05'.toUpperCase()=="ST"
'\ufb06'.toUpperCase()=="ST"


Actual results:

It should return "true" for both statements but instead it returned "false" because the unicode characters '\ufb05' and '\ufb06' are not turned to character "ST" by toUpperCase() function.



Expected results:

It should have returned "true" because uppercase mapping of '\ufb05' and '\ufb05' is "ST". Testing the same on Chrome and Safari returned correct value "ST".

Ref : http://www.fileformat.info/info/unicode/char/fb06/index.htm
Ref : http://www.fileformat.info/info/unicode/char/fb05/index.htm

Comment 1

[:Gijs (he/him)]

Doesn't look like a security bug to me. Also, works for me on 55 beta.

André, is this an ICU thing? Or is this just a JS engine thing?

Comment 2

[Zibi Braniecki [:zbraniecki][:gandalf]]

Seems like landing of ICU59 (bug 1353650) likely fixed it?

Reporter - please test against today's nightly.

WFM. Reopen if needed.

Comment 3

[Jonathan Kew [:jfkthame]]

(In reply to Zibi Braniecki [:gandalf][:zibi] from comment #2)
> Seems like landing of ICU59 (bug 1353650) likely fixed it?
> 
> Reporter - please test against today's nightly.
> 
> WFM. Reopen if needed.

I suspect this is specific to Android release-channel builds (where AFAIK we're not yet using ICU; at least, bug 1344625 is still open). I don't think the ICU 59 update will have affected this (it works in my pre-ICU-59 desktop Nightly, FWIW); rather, my guess is that this works when using ICU-based casing support, and fails with whatever fallback the JS engine uses when ENABLE_INTL_API is not set.

Comment 4

[Zibi Braniecki [:zbraniecki][:gandalf]]

Oh, that makes sense!

Adding bug 1344625 as a dependency then. Hope to have it landed soon! :)

Comment 5

[André Bargull [:anba]]

Special-casing support for toLowerCase/toUpperCase was added in bug 1318403 (mozilla 55).

Comment 6

[André Bargull [:anba]]

Except for U+03A3 (GREEK CAPITAL LETTER SIGMA), Firefox Android without ICU will support all other (locale-independent) special-casing case conversions.