merge revision(s) 55609: [Backport #12568]

	* vm_args.c (setup_parameters_complex): don't raise ArgumentError
	  if an array is given for instance_exec with optional argument.
	  [ruby-core:76300] [Bug #12568]
	  https://github.com/rails/rails/pull/25699


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@55956 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/vm_args.c b/vm_args.c
index 037fb09c1f..9781bc0580 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -587,6 +587,7 @@ setup_parameters_complex(rb_thread_t * const th, const rb_iseq_t * const iseq,
       case arg_setup_lambda:
 	if (given_argc == 1 &&
 	    given_argc != iseq->body->param.lead_num &&
+	    !iseq->body->param.flags.has_opt &&
 	    !iseq->body->param.flags.has_rest &&
 	    args_check_block_arg0(args, th)) {
 	    given_argc = RARRAY_LENINT(args->rest);