Re: BUG #19354: JOHAB rejects valid byte sequences

Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:
> On Wed, Apr 15, 2026 at 1:20 PM Henson Choi <assam258(at)gmail(dot)com> wrote:
>> I understand the appeal of simply deleting a dead-looking encoding,
>> and Thomas' removal patch is clean work. However, Korean archival
>> data from the 1990s (government records, academic repositories, early
>> online corpora) does exist as JOHAB bytes; as a client encoding, JOHAB
>> in PostgreSQL provides a straightforward ingest path
>> (client_encoding=JOHAB, convert_from, then store as UTF-8). Once
>> removed, that path closes with no obvious alternative short of
>> preprocessing outside PostgreSQL. Fixing the verifier preserves the
>> capability at the cost of a ~30-line correction plus tests.

> The counter argument would be that you could use iconv
> --from-code=JOHAB ..., or libiconv, or the codecs available in Python,
> Java, etc for dealing with historical archived data, something that
> data archivists must be very aware of.

Sure. But it's not comfortable to remove a user-visible feature
we've had for decades. My own primary concern about it was that a
correct fix could require non-backwards-compatible behavior changes.
Henson's analysis says that that's not a problem. So assuming this
patch withstands review, I'd be much happier to see it applied than
to remove JOHAB.

No opinion at the moment about whether to back-patch.

regards, tom lane