cae4321112270231e3a4aa8c53c07df194a67dc8 is the first bad commit
commit cae4321112270231e3a4aa8c53c07df194a67dc8
Author: yugui <yugui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date:   Sat Jan 30 12:53:22 2010 +0000

    merges r25494 from trunk into ruby_1_9_1.
    adds a test case for the change
    --
    * vm.c (invoke_block_from_c): return Qnil when its iseq is
      SPECIAL CONST. [ruby-core:26335]

    git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_1@26506 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

:100644 100644 fc42212bb863d800730369d83ffb28a235f93bb7 c1043fac8f9eda5b9167437a13320ecc47504ac4 M      ChangeLog
:040000 040000 940f3c2d6bf3be9b5eb5cd6521b93c678bbc1549 de370ff5657d366af2768424db6237fc5ad7a9de M      test
:100644 100644 76effda1d171a6da2195913f4be260c3f9291b8f f578844ec766f35f2c0c9165835d18a85069c7a9 M      version.h
:100644 100644 f357156993494486892e4020b53c3dff2394d0fe dfdcb17137264d5a6be03955d54902ba91f0a0cb M      vm.c