instance_eval env should remake Fix #3191

Author: ksss

mrbgems/mruby-eval/src/eval.c

@@ -247,6 +247,7 @@ f_instance_eval(mrb_state *mrb, mrb_value self)
     cv = mrb_singleton_class(mrb, self);
     c->ci->target_class = mrb_class_ptr(cv);
     proc = create_proc_from_string(mrb, s, len, mrb_nil_value(), file, line);
+    mrb->c->ci->env = NULL;
     return mrb_vm_run(mrb, proc, mrb->c->stack[0], 0);
   }
   else {

mrbgems/mruby-eval/test/eval.rb

@@ -64,6 +64,8 @@
   assert_equal(['test.rb', 10]) { obj.instance_eval('[__FILE__, __LINE__]', 'test.rb', 10)}
   assert_equal('test') { obj.instance_eval('@test') }
   assert_equal('test') { obj.instance_eval { @test } }
+  o = Object.new
+  assert_equal ['', o, o], o.instance_eval("[''].each { |s| break [s, o, self] }")
 end
 
 assert('Kernel.#eval(string) context') do