[ruby-dev:40233] utf8-mac: Conditional jump or move depends on uninitialised value(s)

"\u05DB\u05BF".encode("UTF-8", "UTF8-MAC") とすると変な値を元に条件分岐
しているようなんですが、いいんでしょうか。

% valgrind ./ruby -ve '"\u05DB\u05BF".encode("UTF-8", "UTF8-MAC")'
==10637== Memcheck, a memory error detector.
==10637== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
==10637== Using LibVEX rev 1854, a library for dynamic binary translation.
==10637== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
==10637== Using valgrind-3.3.1-Debian, a dynamic binary
instrumentation framework.
==10637== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
==10637== For more details, rerun with: -v
==10637==
ruby 1.9.2dev (2010-01-28 trunk 26458) [i686-linux]
==10637== Conditional jump or move depends on uninitialised value(s)
==10637==    at 0x485889D: buf_shift_char (utf8_mac.c:10691)
==10637==    by 0x4858BE4: buf_apply (utf8_mac.c:10763)
==10637==    by 0x4858C70: from_utf8_mac_finish (utf8_mac.c:10787)
==10637==    by 0x811952E: transcode_restartable0 (transcode.c:725)
==10637==    by 0x8119960: transcode_restartable (transcode.c:771)
==10637==    by 0x8119A9C: rb_transcoding_convert (transcode.c:807)
==10637==    by 0x811A4DF: trans_sweep (transcode.c:1143)
==10637==    by 0x811A71A: rb_trans_conv (transcode.c:1235)
==10637==    by 0x811AD1F: rb_econv_convert0 (transcode.c:1354)
==10637==    by 0x811B068: rb_econv_convert (transcode.c:1462)
==10637==    by 0x811CDFE: transcode_loop (transcode.c:2268)
==10637==    by 0x811D725: str_transcode0 (transcode.c:2609)
==10637==
==10637== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 31 from 1)
==10637== malloc/free: in use at exit: 685,265 bytes in 14,651 blocks.
==10637== malloc/free: 15,992 allocs, 1,341 frees, 1,726,147 bytes allocated.
==10637== For counts of detected errors, rerun with: -v
==10637== searching for pointers to 14,651 not-freed blocks.
==10637== checked 455,964 bytes.
==10637==
==10637== LEAK SUMMARY:
==10637==    definitely lost: 533,012 bytes in 9,815 blocks.
==10637==      possibly lost: 4,099 bytes in 1 blocks.
==10637==    still reachable: 148,154 bytes in 4,835 blocks.
==10637==         suppressed: 0 bytes in 0 blocks.
==10637== Rerun with --leak-check=full to see details of leaked memory.
-- 
[田中 哲][たなか あきら][Tanaka Akira]