{Enumerable,Array,Range}#first, {Array,Range}#last with blockfeature/enumerable-first-with-block

* array.c (rb_ary_first, ary_last): extend Array#{first,last} to accept
  a block. If a block is passed, these methods collects only elements
  for which the block returns a truthy value.
* enum.c: extend Enumerable#first to accept a block.
* range.c: extend Range#{first,last} to accept a block.
* gc.c: avoid using rb_ary_last(), because it may call a block.
* test/ruby/test_array.rb: add test
* test/ruby/test_enum.rb: ditto
* test/ruby/test_range.rb: ditto

1 files changed, 3 insertions, 1 deletions

diff --git a/gc.c b/gc.c
index 2baf7a8665..f2853666d7 100644
--- a/gc.c
+++ b/gc.c
@@ -6094,7 +6094,9 @@ void
 rb_gc_register_mark_object(VALUE obj)
 {
     VALUE ary_ary = GET_THREAD()->vm->mark_object_ary;
-    VALUE ary = rb_ary_last(0, 0, ary_ary);
+    VALUE ary = Qnil;
+    if (RARRAY_LEN(ary_ary))
+	ary = RARRAY_AREF(ary_ary, RARRAY_LEN(ary_ary) - 1);
 
     if (ary == Qnil || RARRAY_LEN(ary) >= MARK_OBJECT_ARY_BUCKET_SIZE) {
 	ary = rb_ary_tmp_new(MARK_OBJECT_ARY_BUCKET_SIZE);