[Bug #19877] Fix flip-flop in block

2 files changed, 19 insertions, 0 deletions

diff --git a/parse.y b/parse.y
index c209940712..be68bdf180 100644
--- a/parse.y
+++ b/parse.y
@@ -12472,6 +12472,10 @@ cond0(struct parser_params *p, NODE *node, enum cond_type type, const YYLTYPE *l
 
         return NEW_MATCH2(node, NEW_GVAR(idLASTLINE, loc), loc);
 
+      case NODE_BLOCK:
+        node->nd_end->nd_head = cond0(p, node->nd_end->nd_head, type, loc);
+        break;
+
       case NODE_AND:
       case NODE_OR:
         node->nd_1st = cond0(p, node->nd_1st, COND_IN_COND, loc);
diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 0f71e11f7e..2f1a522dc2 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -465,6 +465,21 @@ class TestParse < Test::Unit::TestCase
     assert_parse_error(%q[def (:"#{42}").foo; end], msg)
   end
 
+  def test_flip_flop
+    [
+      '((cond1..cond2))',
+      '(; cond1..cond2)',
+      '(1; cond1..cond2)',
+      '(%s(); cond1..cond2)',
+      '(%w(); cond1..cond2)',
+      '(1; (2; (3; 4; cond1..cond2)))',
+      '(1+1; cond1..cond2)',
+    ].each do |code|
+      code = code.sub("cond1", "n==4").sub("cond2", "n==5")
+      assert_equal([4,5], eval("(1..9).select {|n| true if #{code}}"))
+    end
+  end
+
   def test_op_asgn1_with_block
     t = Object.new
     a = []