KOI8-T is Tajik encoding partially compatible with KOI8-R. This is default encoding of Tajik locale tg_TJ in glibc (but in X11 locale.alias file it is KOI8-C, issue20087).

Proposed patch adds support for this encoding. I have not found official mapping of KOI8-T and have used a table from Apple's implementation of libiconv. It matches a table in Wikipedia [2] and GNU iconv.

[1] http://www.opensource.apple.com/source/libiconv/libiconv-4/libiconv/tests/KOI8-T.TXT
[2] https://ru.wikipedia.org/wiki/КОИ-8 (Russian)

Ah, actually Apple uses (a fork of) GNU libiconv. So I should correct links.

Ping.

Looks good to me.

New changeset 78de5d040492 by Serhiy Storchaka in branch 'default':
Issue #22681: Added support for the koi8_t encoding.
https://hg.python.org/cpython/rev/78de5d040492

Lots of "LookupError: unknown encoding: koi8_t" test failures (on OS X 10.10) after this commit, for example, in test_codecs:

======================================================================
ERROR: test_basics (test.test_codecs.BasicUnicodeTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/py/dev/3x/source/Lib/test/test_codecs.py", line 1869, in test_basics
    name = codecs.lookup(encoding).name
LookupError: unknown encoding: koi8_t

======================================================================
ERROR: test_decoder_state (test.test_codecs.BasicUnicodeTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/py/dev/3x/source/Lib/test/test_codecs.py", line 2024, in test_decoder_state
    self.check_state_handling_decode(encoding, u, u.encode(encoding))
LookupError: unknown encoding: koi8_t

======================================================================
ERROR: test_seek (test.test_codecs.BasicUnicodeTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/py/dev/3x/source/Lib/test/test_codecs.py", line 1992, in test_seek
    reader = codecs.getreader(encoding)(io.BytesIO(s.encode(encoding)))
  File "/py/dev/3x/blds/uxd/../../source/Lib/codecs.py", line 998, in getreader
    return lookup(encoding).streamreader
LookupError: unknown encoding: koi8_t

----------------------------------------------------------------------
Ran 211 tests in 5.970s

FAILED (errors=5, skipped=17)

Also the 10.6 (Snow Leopard) buildbot:

http://buildbot.python.org/all/builders/AMD64%20Snow%20Leop%203.x/builds/3125/steps/test/logs/stdio

New changeset def3bab79c8f by Serhiy Storchaka in branch 'default':
Added forgotten new files for issues #22681 and #22682.
https://hg.python.org/cpython/rev/def3bab79c8f

Thanks Ned. I just forgive to add new encoding files.

All better, thanks!