vm.c: guard arguments [EXPERIMENTAL]

* vm.c (invoke_iseq_block_from_c): guard arguments on stack, not
  to be clobbered during splatting.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58012 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 0 deletions

diff --git a/vm.c b/vm.c
index 70df6707b8..74ca28c5c7 100644
--- a/vm.c
+++ b/vm.c
@@ -998,12 +998,14 @@ invoke_iseq_block_from_c(rb_thread_t *th, const struct rb_captured_block *captur
     th->passed_bmethod_me = NULL;
 
     CHECK_VM_STACK_OVERFLOW(cfp, argc);
+    cfp->sp = sp + i;
     for (i=0; i<argc; i++) {
 	sp[i] = argv[i];
     }
 
     opt_pc = vm_yield_setup_args(th, iseq, argc, sp, passed_block_handler,
 				 (type == VM_FRAME_MAGIC_LAMBDA ? (splattable ? arg_setup_lambda : arg_setup_method) : arg_setup_block));
+    cfp->sp = sp;
 
     if (me == NULL) {
 	return invoke_block(th, iseq, self, captured, cref, type, opt_pc);