Bug #10464: Bignum同士の乗算の不具合

• Status: Closed
• Assignee: Nishihama (Kohji Nishihama)
• Target version: 2.6
• ruby -v: ruby 2.1.4p265 (2014-10-27 revision 48166) [i386-mingw32]
• Backport: 2.0.0: DONTNEED, 2.1: DONE

[Nishihama (Kohji Nishihama)]

あるBignum同士を乗算すると、誤った値が出力されます。
OSはWindows Vista Home Premium。
なお、ruby 1.8.7 (2008-08-11 patchlevel 72) [i386-mswin32]、ruby 1.9.3p484 (2013-11-22) [i386-mingw32]、200: ruby 2.0.0p353 (2013-11-22) [i386-mingw32]では正常に動作し、
ruby 2.1.3p242 (2014-09-19 revision 47630) [i386-mingw32]では同様に不具合が生じました。

$ ruby bug.rb
5470148495 # 誤った乗算の値
1943359375 # 真の乗算の値
#なお、冗長になるので下10桁のみを表示しています

[Nishihama (Kohji Nishihama)]

対象バージョン：を誤ってしまいました。
正しくは2.1.0です。

[Nishihama (Kohji Nishihama)]

• Copied to Bug #10465: Bug of multiplication between Bignums added

[akr (Akira Tanaka)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r48222.

---

• bignum.c (bary_mul_balance_with_mulfunc): Fix free work area
  location.
  [ruby-dev:48723] [Bug #10464]
  [ruby-core:66044] [Bug #10465]
  Reported by Kohji Nishihama.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN to 2.0.0: DONTNEED, 2.1: REQUIRED

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: DONTNEED, 2.1: REQUIRED to 2.0.0: DONTNEED, 2.1: DONE

Backported into ruby_2_1 at r48272.