compile.c: fix unconditional branch optimization

* compile.c (iseq_peephole_optimize): add dummy `putnil` after a
  `jump` replacing an unconditional branch, to adjust removed
  `dup`.  [ruby-core:86666] [Bug #14708]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63255 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 11 insertions, 0 deletions

diff --git a/compile.c b/compile.c
index 6a7f0ede40..2fadf643ad 100644
--- a/compile.c
+++ b/compile.c
@@ -2893,6 +2893,10 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
 		    ELEM_INSERT_NEXT(&iobj->link, &pobj->link);
 		}
 		if (cond) {
+		    if (prev_dup) {
+			pobj = new_insn_core(iseq, pobj->insn_info.line_no, BIN(putnil), 0, NULL);
+			ELEM_INSERT_NEXT(&iobj->link, &pobj->link);
+		    }
 		    iobj->insn_id = BIN(jump);
 		    goto again;
 		}
diff --git a/test/ruby/test_optimization.rb b/test/ruby/test_optimization.rb
index b2b2b31e03..6bfaf11d7f 100644
--- a/test/ruby/test_optimization.rb
+++ b/test/ruby/test_optimization.rb
@@ -764,4 +764,11 @@ class TestRubyOptimization < Test::Unit::TestCase
     assert_equal(42, obj.foo {result = 42})
     assert_equal(42, result)
   end
+
+  def test_unconditional_branch_to_leave_block
+    assert_valid_syntax("#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      tap {true || tap {}}
+    end;
+  end
 end