On Fri, 23 Aug 2024 10:38:38 GMT, Pratiksha.Sawant <d...@openjdk.org> wrote:

> Mapping ISO-8859-8-I charset to ISO-8859-8.
> Below mentioned 2 aliases are added as part of this:-
> **ISO-8859-8-I**
> **ISO8859-8-I**
> 
> The bug report for the same:- https://bugs.openjdk.org/browse/JDK-8195686

As the original bug submitter I might add that adding a mapping from 
ISO-8859-8-i to ISO-8859-8 is almost certainly correct and makes sense in the 
real world.

The character encodings for ISO-8859-8 and ISO-8859-8-i charsets are exactly 
the same, and the distinction is only due to historical reasons.

Email clients in the past did not "know about" right-to-left languages, instead 
the text was sent as regular ISO-8859-8 mail but sent line-by-line but with 
each line reversed. The reversed lines are displayed LTR (left-to-right) as-is. 
This is what's known as "visual ordering", and is required for old email 
clients.

Newer email clients can do right-to-left, i.e. their text display engines 
started to support RTL display. So it was no longer necessary to send emails in 
"visual order" with reversed lines. But now there's a problem: how does the 
email client know whether the text is in "visual order" (displayed as-is LTR) 
or in "logical order" (displayed as RTL text).

Thus ISO-8859-8-i was introduced. The charset decoding is exactly the same as 
ISO-8859-8, the only difference is in instructing the email client to display 
the lines not as-is LTR, but RTL.

Old email clients cannot show these mails, as they do not know about 
ISO-8859-8-i and do not support RTL display anyways.

The only drawback to adding the alias from ISO-8859-8-i to ISO-8859-8 is if you 
have a very old application (email client) that cannot do RTL display but used 
the newest JDK. Instead of showing an "unsupported charset" error it would then 
show the email but as LTR with each line reversed. I think that would be 
acceptable for almost everyone.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/20690#issuecomment-2354559575

Reply via email to