* ext/gdbm/gdbm.c (fgdbm_select): ditto.
* ext/sdbm/sdbm.c (fsdbm_select): ditto.
* ext/dbm/dbm.c (fdbm_delete): adopt Hash#delete behavior.
* ext/sdbm/sdbm.c (fsdbm_delete): ditto.
* ext/gdbm/gdbm.c: need not to dup key to the block.
* ext/sdbm/sdbm.c : replace RuntimeError with SDBMError.
* eval.c (rb_f_missing): NoMethod error messages for true, false,
nil must respond visibility like for other objects.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2145 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
matz