From 47141797bed55eb10932c9a722a5132f50d4f3d8 Mon Sep 17 00:00:00 2001 From: Yusuke Endoh Date: Mon, 16 Mar 2020 23:03:22 +0900 Subject: hash.c: Do not use the fast path (rb_yield_values) for lambda blocks As a semantics, Hash#each yields a 2-element array (pairs of keys and values). So, `{ a: 1 }.each(&->(k, v) { })` should raise an exception due to lambda's arity check. However, the optimization that avoids Array allocation by using rb_yield_values for blocks whose arity is more than 1 (introduced at b9d29603375d17c3d1d609d9662f50beaec61fa1 and some commits), seemed to overlook the lambda case, and wrongly allowed the code above to work. This change experimentally attempts to make it strict; now the code above raises an ArgumentError. This is an incompatible change; if the compatibility issue is bigger than our expectation, it may be reverted (until Ruby 3.0 release). [Bug #12706] --- struct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'struct.c') diff --git a/struct.c b/struct.c index 79131db2bd..3042d3bed5 100644 --- a/struct.c +++ b/struct.c @@ -821,7 +821,7 @@ rb_struct_each_pair(VALUE s) RETURN_SIZED_ENUMERATOR(s, 0, 0, struct_enum_size); members = rb_struct_members(s); - if (rb_block_arity() > 1) { + if (rb_block_pair_yield_optimizable()) { for (i=0; i