This issue was solved with changeset r41733.
Kenta, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
* ext/bigdecimal/bigdecimal.c (BigMath_s_exp): Fix for the cases when
the argument x is not a BigDecimal.
This change is based on the patch made by Garth Snyder.
[Fix GH-332] https://github.com/ruby/ruby/pull/332
This change is based on the patch made by Heesob Park and Garth Snyder.
[Bug #6862] [ruby-core:47145]