From: sam.saffron@...
Date: 2020-12-17T04:26:17+00:00
Subject: [ruby-core:101492] [Ruby master Bug#17400] Incorrect character	downcase for Greek Sigma

Issue #17400 has been updated by sam.saffron (Sam Saffron).


Java has complicated opinions as well: 

class Main {  
  public static void main(String args[]) { 
    
    System.out.println("��".toLowerCase());
    System.out.println("����s".toLowerCase()); 
    System.out.println("����".toLowerCase()); 
    System.out.println("����, sss".toLowerCase());
    System.out.println("����,sss".toLowerCase());
    System.out.println("����;sss".toLowerCase());
    System.out.println("����:sss".toLowerCase());
    System.out.println("����: sss".toLowerCase());
    System.out.println("����^sss".toLowerCase());
    System.out.println("����.sss".toLowerCase());
    System.out.println("����. sss".toLowerCase());
    System.out.println("����'sss".toLowerCase());
    System.out.println("����$sss".toLowerCase());
  } 
}

��
����s
����
����, sss
����,sss
����;sss
����:sss
����: sss
����^sss
����.sss
����. sss
����'sss
����$sss

full stop (.) and single quote (') are handled differently than comma (,) and other special chars. This is one very tricky edge case. 

  

----------------------------------------
Bug #17400: Incorrect character downcase for Greek Sigma
https://bugs.ruby-lang.org/issues/17400#change-89270

* Author: xfalcox (Rafael Silva)
* Status: Open
* Priority: Normal
* Assignee: duerst (Martin D��rst)
* ruby -v: ruby 3.0.0dev (2020-12-16T18:46:44Z master 93ba3ac036) [x86_64-linux]
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN
----------------------------------------
An issue caused by this bug was first reported at Discourse support community at https://meta.discourse.org/t/unicode-username-results-in-error-loading-profile-page/173182?u=falco.

The issue is that in Greek, there are two ways to downcase the letter ��������

 - �������� when it is used at the end of a word
 - �������� anywhere else

NodeJS follows this rule:

```
���  node
Welcome to Node.js v12.11.1.
Type ".help" for more information.
> "������������".toLowerCase()
'������������'
```

Python too:

```
��� python
Python 3.8.2 (default, Nov 23 2020, 16:33:30) 
[GCC 10.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> "������������".lower()
'������������'
```

Ruby (both 2.7 and 3) doesn't:

```
���  ruby --version           
ruby 3.0.0dev (2020-12-16T18:46:44Z master 93ba3ac036) [x86_64-linux]
���  irb           
irb(main):001:0> "������������".downcase
=> "������������"
```

```
���  ruby --version
ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-linux]
���  irb
irb(main):001:0> "������������".downcase
=> "������������"
```




-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:ruby-core-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>