since octal literals are formed by three digits at most.

* eval.c (rb_eval_cmd): cbase should not be NULL; it should be
  either ruby_wrapper or Object.

* enum.c (enum_each_with_index): should return self.

* process.c (proc_setpgrp): should return value for non-void function.

* process.c (proc_getpgid): should raise exception if getpgid() return -1.

* string.c (rb_str_ljust): should return a duplicated string.

* string.c (rb_str_rjust): ditto.

* string.c (rb_str_center): ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_6@2186 b2dd03c8-39d4-4d8f-98ff-823fe69b080e