[Bug 27878] New: Big5 : handling of U+5341(and potentially other dupe points) is incompatible with Firefox, Chrome and IE 11

https://www.w3.org/Bugs/Public/show_bug.cgi?id=27878

            Bug ID: 27878
           Summary: Big5 : handling of U+5341(and potentially other dupe
                    points) is incompatible with Firefox, Chrome and IE 11
           Product: WHATWG
           Version: unspecified
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Encoding
          Assignee: annevk@annevk.nl
          Reporter: jshin@chromium.org
        QA Contact: sideshowbarker+encodingspec@gmail.com
                CC: mike@w3.org, www-international@w3.org

Spun off from bug 16389 

Duplicate entries in index-*.txt is
http://lists.w3.org/Archives/Public/www-archive/2012Apr/0062.html


https://encoding.spec.whatwg.org/#index-pointer has the following:



The index pointer for code point in index is the first pointer corresponding to
code point in index, or null if code point is not in index.

And, the big5 encoder has the following steps:

3. Let pointer be the index pointer for code point in index big5.

4. If pointer is null, return error with code point.

....




Using the first pointer for round-trip while using others for decoding-only
(toUnicode) seems to lead to at least one discrepancy from Firefox 35, Chrome
and IE 11 in Big5. 

index-big5.txt has two entries for U+5341 as shown below: 

  5287   0x5341  十 (<CJK Ideograph>)
  5512   0x5341  十 (<CJK Ideograph>)

5287 corresponds to {0xA2 0xCC} and 5512 is {0xA4 0x51}. 

All three browsers above encode U+5341 to {0xA4 0x51} in Big5 instead of {0xA2
0xCC}.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

Received on Wednesday, 21 January 2015 20:30:08 UTC