[ruby-cvs:73611] nobu:r66510 (trunk): Prohibit circular causes [Bug #15447]

[nobu at ruby-lang.org]

nobu	2018-12-23 20:11:36 +0900 (Sun, 23 Dec 2018)

  New Revision: 66510

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=66510

  Log:
    Prohibit circular causes [Bug #15447]

  Modified files:
    trunk/eval.c
    trunk/test/ruby/test_exception.rb