[ruby-core:64093] [ruby-trunk - Bug #10097] Case-insensitive Regexp matching for Windows-1252 not working for ŠšŽžŒœÿŸ

Issue #10097 has been updated by Nobuyoshi Nakada.


I've forgotten the test file, "test/ruby/enc/test_windows_1252.rb", and added it now.
What tests are needed?

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Bug #10097: Case-insensitive Regexp matching for Windows-1252 not working for ŠšŽžŒœÿŸ
https://bugs.ruby-lang.org/issues/10097#change-48105

* Author: Martin Dürst
* Status: Open
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: 1.9.3p545
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
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By chance I had a look at enc/iso_8859_1.c and found

~~~C
ENC_REPLICATE("Windows-1252", "ISO-8859-1")
~~~
on line 288. But this does not work for case folding:

~~~ruby
# http://en.wikipedia.org/wiki/Windows-1252
s1 = "\u0160".encode 'windows-1252' # 'Š'
r1 = Regexp.new("\u0161".encode('windows-1252'), Regexp::IGNORECASE) # /š/i
s1 =~ r1
   # => nil
s2 = "\u0178".encode 'windows-1252' # 'Ÿ'
r2 = Regexp.new("\u00FF".encode('windows-1252'), Regexp::IGNORECASE) # /ÿ/i
s2 =~ r2
   # => nil
s3 = "\u00C0".encode 'windows-1252' # 'À'
r3 = Regexp.new("\u00E0".encode('windows-1252'), Regexp::IGNORECASE) # /à/i
s3 =~ r3
   # => 0
~~~

So case-insensitive matching works when both characters are in iso-8859-1, but not when one (ÿŸ) or both (ŠšŽžŒœ) characters are not in iso-8859-1.



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